702STRUCTURAL CONCRETE

702.01Description

This work shall consist of furnishing and placing portland cement concrete for structures and incidental construction in accordance with 105.03.

702.02Classes of Concrete

The following classes of concrete shall be used where specified.

CLASS OF CONCRETE A B C Cement content in lb/cu yd 564 470 658 Maximum water/cement ratio in lb of water per lb of cement 0.450 0.620 0.443 Minimum water/cement ratio in lb of water per lb of cement* 0.380 0.400 0.380 * The minimum water/cement ratio for all slipformed railings shall be 0.360.

702.01

Unless specified otherwise, the concrete used shall be class A. When class A is specified, class C may be used as a substitution. When class B is specified, class A or class C may be used as a substitution.

Class A concrete shall be used in the following:

Concrete in footings shall be class B.

Concrete in superstructure, integral bents, and railings shall be class C. 30

MATERIALS

702.03Materials

Materials shall be in acco rdance with the following:

Admixtures for Use in Concrete .................................. 912.03 Castings ....................................................................... 910.05 Concrete Coarse Aggregate For exposed concrete, Class A or Higher ............... ITM 226, 904 40 For non-exposed concrete, Class B or Higher ........ ITM 226, 904 Curing Materials .......................................................... 912.01 Elastomeric Bearings ................................................... 915.04 Fabric for Wa terproofing ............................................. 918.06 Fly Ash ........................................................................ 901.02 Geotextile for Use with Underdrains ........................... 918.03 High Density B earing Strips ........................................ 906.08 Permanent Metal Forms .............................................. 910.03 Polychloroprene Joint Membrane and Adhesive ......... 906.02(a)4 50 Preformed Expansion Joint Filler ................................ 906.03 Portland Cement .......................................................... 901.01(b) Silica Fume .................................................................. 901.04 Slag Cement ................................................................ 901.03 Utility Asphalt, UA-1 .................................................. 902.01(d) Water ........................................................................... 913.01 702.03

Drainage pipe through concrete masonry shall be in accordance with 715.

Grout material for field drilled holes shall be selected from the QPL of Chemical 60 Anchor Systems.

702.04Shipping and Storage

The cement shall be well protected from rain and moisture. All cement damaged by moisture or which fails to meet the specified requirements shall be rejected and removed from the work. Cement stored for a period longer than 60 calendar days shall be retested before being used on the work. Cement of different brands, types, or from different mills shall be stored separately.

CONSTRUCTION REQUIREMENTS 70

702.05Proportioning

Control of PCC for air content, slump, or relative yield will be determined from tests performed by the Engineer. Concrete and necessary labor for sampling shall be furnished by the Contractor as required by the Engineer. Testing will be in accordance with the Frequency Manual.

A CMDS shall be submitted seven calendar days prior to production and be approved by the Engineer on the Departme nt provided spreadsheet. The absolute volume of the mix design shall be 27.0 cu ft at the design air content of 6.5%. 80

The aggregate blend on the CMDS may produce an optimized aggregate gradation in accordance with the Department provided spreadsheet. If an optimized aggregate gradation is used, it shall consist of, at a minimum, one concrete coarse aggregate and one fine aggregate, No. 23. One additional class A or higher for exposed or class B or higher for non-exposed intermediate-sized coarse aggregate may be included if approved by the Engineer.

The proportion of ingredients of each batch shall be within the following limits and shall be as approved. 90

The relative yield of the concrete shall be determined in accordance with 505. The concrete when produced shall provide a relative yield of 1.00 ±0.02. When the relative yield is outside the tolerances, adjustments to the batch weights shall be made. The minimum amount of cement shall be used for the desired class of concrete. The cement content shall not be increased more than 60 lb/cu yd. The relative yield of the concrete shall be maintained as stated above. If Type IP or Type IP-A cements are to be used in the structural concrete, the cement content shall be increased by a multiplier of 1.06 times the minimum amount of cement required or the desired increased cement content for the specified class of concrete. 100

For example: 1.06 x 564 = 598 lb/cu yd for class A concrete. 702.04

Fly ash from a qualified source may be used as a partial replacement for portland cement. The substitution of fly ash for portland cement will not be allowed in conjunction with the use of slag cement or blended cement types IP, IP-A, IS, or IS-

minimum 1.25:1 ash-to-cement replacement ratio, by weight.

Slag cement from a qualified source may be used as a partial replacement for 110 portland cement. The substitution of slag cement for portland cement will not be allowed in conjunction with the use of blended cement types IP, IP-A, IS, IS-A, or fly ash. Mix designs will be based on using a maximum 30% cement substitution with a 1:1 slag-to-cement ratio, by weight.

Slag cement or silica fume in accordance with 709.05(c) shall be used in all bridge decks, reinforced concrete bridge approaches, and terminal joint lugs.

Blended portland pozzolan cements, fly ash, and slag cement may be used in concrete when the ambient temperature is above 45°F during the entire placement 120 period. Immediately following placement, the average ambient te mperature shall be above 45°F for the entire curing period. The average temperature shall be calculated based on hourly temperature measurements taken at the jobsite or from published weather station data within 10 miles of the jobsite. If the temperature restrictions are not met during placement or during the require d curing period, curing shall continue and the element shall not be put into service until the strength requirements in accordance with 702.24 are met. If no test specimens are availa ble to determine the concrete strength, curing shall continue and the concrete will be adjudicated as failed material. In no case shall the curing period be reduced below the minimum number of days specified for the element. 130

All concrete shall have an air content of 6.5% ±1.5% by volume. Air content shall be determined in accordance with 505.

Powdered admixtures shall be measured by weight. Paste or liquid admixtures shall be measured by weight or volume. All admixtures shall be within 3% of the amount required. When admixtures are used in small quantities in proportion to the cement, as is the case for air-entraining admixtures, mechanical dispensing equipment shall be provided.

Class A concrete shall contain a water-reducing admixture. Class C concrete shall contain a retarding admixture when either the air temperature is above 70°F or the concrete temperature is above 80°F, or if retardation is required due to the structure design, or due to the proposed pour sequenc e such as for the requirements for floor slab pours set out in 704.04. Air-entraini ng cements will not be allowed in class C concrete.

702.05

If the contract requires stay-in-place me tal forms for the bridge deck or if the Contractor elects to use such forms, the br idge deck concrete shall incorporate class AP coarse aggregate instead of class A. 150

702.06Measuring and Batching

Unless otherwise specified, the minimum batch shall be 2 cu yds. Measuring and batching of materials shall be performed at a batching plant. Different kinds or sources of coarse aggregate or different brands of cement shall not be used in any unit of the structure, except in an emergency and with written approval.

Either sacked or bulk cement may be used . No fraction of a sack of cement shall be used in a batch of concrete unless the cement is weighed. All bulk cement shall be 160 weighed on an approved weighing device. The bulk cement weighing hopper shall be sealed and vented to preclude dusting during operation. The discharge chute shall not be suspended from the weighing hopper and shall be arranged so that cement does not lodge in it or leak from it. Accuracy of batching shall be ±1% of the required weight.

If fly ash is used as a pozzolan in portland cement concrete, the cement and fly ash shall be weighed and discharged separately when a manual operation is utilized. When an automatic batching plant is utilized, the fly ash may be weighed into the cement weigh hopper in one cumulative operation with the portland cement always being weighed in first. 170

Water may be measured either by volume or by weight. The accuracy of measuring the water shall be within 1% of the required amount.

The batch plant site, layout, equipment, and provisions for transporting material shall assure a continuous supply of reasonably uniform material to the work. Aggregate stockpiles shall be in areas sufficiently well drained to prevent any dirt underneath the stockpile from becoming softened and pumping into the aggregate to a 180 level from which the aggregate is to be removed and used in the work. Stockpiles shall be built in layers not to exceed 6 ft in depth. Upper layers shall be prevented from spilling over the sides of the layers below.

The removal of aggregates from stockpiles shall be performed so that segregation will not occur. Aggregate which has become mixed with dirt shall not be used in the work.

Washed aggregates shall drain for at least 12 h prior to use. An increase in the drainage time may be required, as directed , at any time when the moisture becomes 190 non-uniform in aggregates from any source. Aggregates from different sources shall not be stockpiled together without written approval.

702.06

Batching shall be conducted to obtain the weights of materials required within a tolerance of ±2%.

The batching plant shall include bins, weighing hoppers, and scales for the fine aggregate and for each size of coarse aggregat e. If cement is used in bulk, a bin, hopper, and scale for cement shall be included. If fly ash is used, the separation of 200 cement and fly ash bins will be as approved. Bins with adequate separate compartments for fine aggregate and for each size of coarse aggregate shall be provided in the batching plant.

Means of control shall be provided so that as the quantity required in the weighing hopper is approached the material may be added slowly and shut off with precision. A port or other opening for removing an overload from the hopper shall be provided. A port for sampling cement shall be provided and may be either the overload port or a separate port located at any point from the bottom of the storage bin to the weigh

hopper. The sampling port shall be located and constructed to provide a representative210

sample of the cement being used. Weighing hoppers shall be constructed to eliminate

accumulation of tare materials and to discharge fully.

For applied loads of 1,000 lb and greater on the cement scale and applied loads of

4,000 lb and greater on the aggregate scale, the scales shall be accurate to 0.5%. For

applied loads of less than 1,000 lb and 4,000 lb for the cement and aggregate scales,

respectively, the scales shall be accurate to 2.0% or one graduation, whichever is

larger. Poises shall be designed to be locked in any position to prevent unauthorized

change of position. Scales will be inspected as often as necessary to ensure their

continued accuracy. A minimum of ten 50 lb weights shall be provided for testing of220

scales.

Batching plants may be equipped with approved automatic weighing devices to

proportion aggregates and bulk cement.

When batches are hauled to the mixer, bulk cement shall be transported either in

waterproof compartments or between the fine and coarse aggregates. When cement is

placed in contact with the aggregates, batches may be rejected unless mixed within

1 1/2 h of such contact. Sacked cement may be transported on top of the aggregates.230

Batches shall be delivered to the mixer separate and intact. Each batch shall be

dumped cleanly into the mixer without loss and, when more than one batch is carried

on the truck, without spillage of material from one batch compartment into another.

702.07Mixing

Concrete may be mixed at the site of construction, at a central point, or wholly or

in part in truck mixers. Retempering concrete by adding water or by other means will

not be allowed after initial set. When the concrete is delivered in transit mixers and

702.07

624

when allowed, additional water may be added occasionally to increase the slump.240

When water is added to the mix, additional mixing shall be performed as directed with

all operations completed within the time limits in accordance with 702.09(c). The

amount of water added shall be determined accurately and noted on the batch ticket.

Such addition of water will not be allowed as a continuing operation. The total of all

water included in the mix shall not exceed the maximum in accordance with 702.02.

Concrete that is outside the specified slump limits at time of placement shall not

be used. Except as required in 702.05 for class A and class C concrete, chemical

admixtures Type A, Type B, Type D, Type F, and Type G may be used in the concrete.

Chemical admixtures Type C and Type E will be allowed only with prior written250

permission.

702.08Mixing at Site of Work

For concrete to be acceptable, no more than 1 h shall elapse from the time mixing

water has entered the mixer until the mixed batch is deposited into the forms.

The concrete shall be mixed in an approved batch mixer having a rated capacity

of no less than 188 lb except for pours of 20 cu yds or less, or where otherwise

specified, a 94 lb minimum capacity mixer may be used. Mixers shall produce a

uniform distribution of ingredients throughout the mass. No mixer shall be operated260

beyond its factory rated capacity.

The concrete shall be mixed no less than 60 s after all ingredients, including water,

are in the mixer.

During the period of mixing, the drum shall rotate at the speed for and it was

designed, which shall be no less than 14 and no more than 20 revolutions per minute.

If this procedure does not mix the concrete thoroughly, a sufficient additional number

of turns at the same rate shall be made until a thorough mixing of the ingredients is

obtained.270

The mixer shall be equipped with a batch meter for counting the number of

batches discharged and a timer for automatically locking the discharge chute to prevent

emptying the mixer prior to the specified minimum mixing time. Mixers shall be

equipped with mechanical means for preventing the addition of ingredients, including

water, after mixing is started. The first batch shall contain an additional quantity of

cement, fine aggregate, and water sufficient to coat the inside surface of the drum to

avoid diminishing the mortar content of the initial batch. The entire contents of the

drum shall be removed before the materials for the next batch are introduced. Upon

cessation of mixing for any considerable time, the drum shall be cleaned thoroughly.280

Structural concrete shall be mixed only in such quantities as are required for

immediate use and shall be placed while fresh before initial set has occurred. Hand

mixing will not be allowed except in an emergency and then only with permission.

Hand mixing shall be done on a watertight platform in such manner and so continued

702.08

625

to ensure a homogeneous mixture of the required consistency. Hand mixed batches

shall not exceed 1/2 cu yd in volume.

702.09Ready-Mixed Concrete

290

Ready-mixed concrete shall be mixed and delivered by means of one of the

following operations:

transported to the point of delivery in a truck-agitator or

truck-mixer at agitating speed or in non-agitating equipment in

accordance with 702.09(d). Concrete delivered under these

provisions shall be known as central-mixed concrete.

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in a truck-mixer. Concrete delivered under these provisions

shall be known as shrink-mixed concrete.

these conditions shall be known as transit-mixed concrete.

The source of ready-mixed concrete shall be approved prior to delivery of the

concrete. This approval will be based on the capacity and condition of the equipment,

volume of production, and length of haul, with consideration of the use of the concrete.310

Original approval will not constitute continued approval if satisfactory concrete or rate

of delivery is not maintained.

Approval may be refused or previous approval may be withdrawn for a truck

mixer or for a part of equipment not functioning in such manner as to produce and

deliver uniform concrete to the site of the work at a uniform rate.

Before a pour is started, the number of trucks to be assigned to the work, the rate

of production, and all other conditions necessary for furnishing satisfactory concrete

shall be subject to approval. Such assigned equipment shall be in satisfactory operating320

condition prior to the start of the pour. Once assigned to a pour, equipment shall not

be diverted for another purpose without approval.

Mixers and agitators shall be in accordance with the following:

may be truck-mixers or truck-agitators. Each mixer and agitator

shall have attached metal plates, prominently placed and plainly

marked, indicating the various designed uses of the equipment,330

the volume capacity of mixed concrete, the speed of rotation of

702.09

626

the mixing drum, and the manufacturer’s name and address.

Stationary mixers shall be equipped with an acceptable timing

device which does not enable the batch to be discharged until

the specified mixing time has elapsed. Truck-mixers shall be

equipped with means by which the number of revolutions of the

drum may be verified readily. The counters shall be actuated at

the time of starting mixing at mixing speed.

without overload, shall be capable of combining the ingredients

of the concrete within the specified time into a thoroughly

mixed and uniform mass and of discharging the concrete with a

satisfactory degree of uniformity in accordance with

without overload, shall be capable of maintaining the mixed

concrete in a thoroughly mixed and uniform mass and of

discharging the concrete with a satisfactory degree of350

uniformity in accordance with 702.09(b)4.

discharged at approximately the 1/4 and 3/4 points of each load.

If the slumps differ by more than 1 in. when the average slump

is 3 in. or less, or by more than 2 in. when the average slump is

greater than 3 in., the mixer or agitator shall not be used until

conditions are corrected, except as set out in 702.09(b)5.

longer mixing time or with a smaller load will enable the

requirements in 702.09(b)4 to be met.

conditions due to the accumulations of hardened concrete or

mortar or to wear of blades. When such change of conditions is

found, the tests described in 702.09(b)4 shall be repeated.

Mixers and agitators shall be operated within the limits of the capacity and speed370

of rotations designated by the manufacturer. The following shall apply in fulfilling

these requirements.

than 60 s. Mixing time shall be measured from the time all

cement and aggregates are in the drum. The batch shall be so

charged into the mixer that some of the water enters in advance

702.09

627

of the cement and aggregates. All required water shall be in the

drum by the end of the first quarter of the specified mixing time.

380

stationary mixer may be reduced to the minimum required to

mix the ingredients, or approximately 30 s. Mixing shall then

be completed in a truck-mixer by no less than 50 and no more

than 100 revolutions of the drum or blades at the rate of rotation

designated by the manufacturer of the equipment as mixing

speed. Additional mixing, if required, shall be at the speed

designated by the manufacturer as agitating speed.

capacity, the number of revolutions of the drum or blades at

mixing speed shall be no less than 70 and no more than 100, but

not less than that recommended by the mixer manufacturer.

concrete that has been completely mixed in a stationary mixer,

further mixing during transportation shall be at the speed

designated by the manufacturer of the equipment as agitating

speed.

400

concrete, the concrete shall be delivered to the site of the work

and its discharge completed within 90 minutes after the

introduction of the mixing water to the cement and aggregates,

or the introduction of cement to the aggregates, unless a shorter

time is otherwise specified. When a truck-mixer is used for the

complete mixing of the concrete, the mixing operations shall

begin within 30 minutes after the cement has been added to the

aggregates.

410

aggregates and water at the batching plant and with bagged

cement at the point of delivery, provided the truck-mixer is then

operated at mixing speed for the required additional revolutions

and satisfactory concrete is produced.

the mixing water for succeeding batches.

Central mixed concrete may be transported from the mixing plant to the place of

use in non-agitating equipment as approved. The following shall apply in fulfilling

these requirements.

702.09

628

metal containers equipped with gates that enable control of the

discharge of the concrete. Covers shall be provided for

protection of the concrete when required.

thoroughly mixed and uniform mass and discharged with the

degree of uniformity in accordance with 702.09(d)3. Discharge

shall be completed within 30 minutes after the introduction of

the mixing water to the cement and aggregates.

slump differs by more than these tolerances the non-agitating

equipment shall not be used until the conditions are corrected

in accordance with 702.09(d)4.

440

agitating equipment is operated at minimum capacity for the

maximum time of haul and with the concrete mixed the

minimum time, the equipment may still be used when operated

using smaller loads, shorter hauls, or longer mixing times, or

combinations thereof, which enables 702.09(d)3 to be met.

702.10Pumping Concrete

If the Contractor elects to convey concrete by means of pumping, the concrete

shall be handled to minimize disturbance to the concrete which significantly alters the450

properties of the concrete being pumped, especially the loss or variability of the air

content. The pumping equipment shall be mechanically sound, suitable in kind, and

adequate in capacity for the proposed work. The concrete shall not be pumped through

aluminum or aluminum alloy pipe. All pipes used for pumping concrete shall be kept

clean and free from coatings of hardened concrete. Pump lines shall not rest directly

on epoxy coated reinforcing bars. The pumping equipment shall be located such that

operational vibrations will not damage freshly placed concrete.

When placing concrete directly from a truck mounted boom, the concrete pump

lines shall have a flexible end section at least 10 ft long. Methods of placement shall460

result in a steady and continuous discharge. If necessary, this may require the use of a

restrictive device at or near the end of the discharge tube, the laying the flexible end

section horizontally, or other means. For the initial placement of concrete pours which

are predominantly vertical, the discharge end of the flexible end section shall be within

2 ft of the bottom of the pour.

The Contractor shall submit a description of the intended pumping procedures

which it intends to use, and shall notify the Engineer as to the pumping procedure at

least 24 h in advance of concrete placement.

702.10

629

470

702.11Cold Weather Concrete

When it is necessary to place concrete at or below an atmospheric temperature of

40°F, or whenever it is determined that the temperature may fall below 40°F within

the curing period, the water, the aggregates, or both shall be heated and suitable

enclosures and heating devices provided. Cold weather concrete shall be placed at the

risk of the Contractor and shall be removed and replaced with no additional payment

if it becomes frozen or otherwise damaged.

When aggregates or water are heated, the resulting concrete shall have a

temperature of at least 50°F and not more than 80°F at the time of placing. Heating480

equipment or methods which alter or prevent the entrainment of the required amount

of air in the concrete shall not be used. The equipment shall be capable of heating the

materials uniformly. Neither aggregates nor water used for mixing shall be heated to

a temperature exceeding 150°F. When aggregates or water are heated to 100°F or

above, they shall be combined first in the mixer before the cement is added. The

maximum temperature of concrete produced with heated aggregates shall be 90°F.

Materials containing frost or lumps of frozen material shall not be used.

Stockpiled aggregates may be heated using dry heat or steam. Aggregates shall

not be heated directly by gas or oil flame or on sheet metal over fire. However, a drier490

may be used if approved.

When aggregates are heated in bins, steam-coil heating, water-coil heating, or

other methods which are not detrimental to the aggregates may be used. The use of

salt or other chemicals to accelerate hardening of the concrete will not be allowed

unless approved in writing.

Immediately after a pour is completed, the freshly poured concrete and forms shall

be covered to form a complete protective enclosure around the element being poured.

If the element is a bridge deck, the enclosure shall encompass the top, bottom, and all500

sides. The air within the entire enclosure shall be maintained at a temperature above

50°F for a minimum of 144 h for bridge decks, the top surface of reinforced concrete

slab bridges, and for a minimum of 72 h for all other concrete. If for any reason this

minimum temperature is not maintained, the heating period shall be extended. When

dry heat is used, means shall be provided to maintain adequate moisture in the air

within the enclosure.

All necessary measures shall be taken during protective heating to keep the

heating equipment in continuous operation and to maintain the proper temperature

around all sides, including the top and bottom of the concrete. Adequate fire protection510

shall be provided where heating is in progress and such protection shall be accessible

at all times.

Where practicable, forms insulated with at least 2 in. thick blankets made of

fiberglass, rock wool, balsam wool, or similar commercial material capable of

702.11

630

maintaining the surface of the concrete at no less than 50°F may be used in lieu of

other protection of concrete involving housing and heating. When forms are insulated,

exposed horizontal surfaces shall be protected with a similar layer of the insulating

material fastened securely in place. If the insulated forms do not maintain the proper

temperature at the surface of the concrete, auxiliary protection and heat shall be used.520

702.12Consistency

Slump will be measured in accordance with 505 and shall be no less than 1 in. and

no more than 6 in.

702.13Forms

Forms shall be mortar-tight and sufficiently rigid to prevent distortion due to the

pressure of the concrete and other loads incident to the construction operations,530

including vibration. Forms shall be constructed and maintained to prevent the opening

of joints due to shrinkage of the lumber.

Unless otherwise provided, all forms for exposed surfaces except the undersides

of girders, slabs, and arch rings shall be lined with approved plywood, metal, or similar

satisfactory composition. The lining shall not be sprung into place. Before concrete is

placed, all open joints shall be filled with a satisfactory filler which is impervious to

moisture, does not stain or otherwise injure the concrete, and produces a tight joint.

The lining shall present a smooth uniform surface. Lining of sufficient thickness to

resist the pressure of the concrete without deflection may be applied directly to the540

studding if it otherwise complies with the foregoing provisions for form lining.

In designing forms, fresh concrete shall be considered as a liquid weighing 150

lb/cu ft for vertical loads and 100 lb/cu ft for horizontal pressure. A live load allowance

of 50 lb/sq ft shall be used on horizontal projections of surfaces. The scheme of

formwork for work on a span over active railroad tracks shall provide a horizontal

clearance of not less than 8 ft from the centerline of track and a clearance height of not

less than 22 ft from the top of the track rail.

Spreader blocks and bracing shall be removed from the inside of the forms before550

concrete is placed and no portion of wood shall be left in the concrete.

Forms for exposed concrete edges shall be chamfered 3/4 in. Forms shall be given

a bevel or draft in the case of all projections, such as girders and copings, to ensure

easy removal.

Approved ties or anchorages within the forms shall be so constructed as to enable

their removal to a depth of at least 1 in. from the face without injury to the concrete.

Ties may be metal or fiberglass. Ties shall be capable of supporting the designed loads.560

Fiberglass ties shall be ground flush with the face of the concrete surfaces. The cavities

702.12

631

shall be filled with cement mortar and the surface left sound, smooth, even, and

uniform in color. Filling of the cavities will not be required between the fascia beams

or girders on the underside of decks, the bottom surface of slab decks, or the bottom

deck surface of box culverts. In general, tie rods shall be designed to also act as struts

or spreaders. The use of wood struts will not be allowed in copings, railings, and walls

less than 2 ft thick. Devices which, when removed, leave an opening entirely through

the concrete will not be allowed unless approved in writing. Wire ties shall not be

used.

570

Where the bottom of the forms is inaccessible, the lower form boards shall be left

loose or other provisions made so that extraneous material may be removed from the

forms immediately before placing the concrete.

All forms shall be treated with a formulated form coating that allows them to be

released without adhering, discoloring, or otherwise damaging the concrete.

The specifications for forms as they regard design, mortar tightness, filleted

corners, beveled projections, bracing, alignment, removal, re-use, and oiling apply to

metal forms. The metal used for forms shall be of such thickness that the forms remain

true to shape. All bolt and rivet heads shall be countersunk. Clamps, pins, or other

connecting devices shall be designed to hold the forms together rigidly and to allow

removal without injury to the concrete. Metal forms which do not present a smooth

surface or do not line up properly shall not be used. Care shall be exercised to keep

metal forms free from rust, grease, or other foreign matter.590

Fabricated permanent metal forms for concrete deck slabs may be used as an

alternate method of forming on a steel beam, steel girder, prestressed concrete I-beam,

prestressed concrete spread box beam, or prestressed concrete bulb-T beam bridge.

Permanent metal forms shall not be removed and shall otherwise be in accordance with

the applicable requirements of this section.

The metal forms shall be designed based on dead load of the forms, reinforcing

bars, and plastic concrete plus 50 lb/sq ft for construction loads. The unit working600

stress in the steel sheet shall be not more than 0.725 of the specified minimum yield

strength of the material furnished but not to exceed 36,000 psi. Deflection under the

weight of the forms, the plastic concrete, and the reinforcing bars shall not exceed

1/180 of the form span or 1/2 in., whichever is less. However, the deflection loading

shall not be less than 120 lb/sq ft total. The allowable form camber shall be based on

the actual dead load condition. Camber shall not be used to compensate for deflection

in excess of the foregoing limits. The design span of the form sheets shall be the clear

702.13

632

span of the form plus 2 in. measured parallel to the form flutes. If the design span of

the form sheets exceeds 9.5 ft, concrete will not be allowed to be placed in the valleys

of the corrugations of the metal forms. Physical design properties shall be computed610

in accordance with requirements of the American Iron and Steel Institute

Specifications for the Design of Cold Formed Steel Structural Members.

All reinforcing bars shall have a minimum clearance of 1 in. from the forms. The

plan dimensions from the top surface for all primary deck reinforcing bars shall be

maintained. The deck reinforcing bars shall be tied down at a maximum of 6 ft centers.

Permanent metal forms shall not remain in place closer than 1 ft from any joint exposed

to the underside of the slab, except when an overlay is used on the deck.

Fabricator’s working drawings shall be submitted for approval. These drawings620

shall indicate the grade of steel and the physical and section properties for all

permanent metal bridge deck form sheets. If the bridge is a steel beam or steel girder

structure, these drawings shall also include a clear indication of locations where the

forms are supported by steel beam flanges subject to tensile stress. The drawings shall

be certified by a registered professional engineer prior to submittal.

Form sheets shall not rest directly on the top of the beam flanges. Sheets shall be

securely fastened to the form supports and shall have a minimum bearing length of 1

in. at each end. All attachments shall be made by welds, bolts, clips, or other approved

means. Except as amended by these specifications, welding and welds shall be in630

accordance with the requirements of 711.32 pertaining to fillet welds. However, 1/8

in. fillet welds will be allowed. The vertical leg of angles used as form supports shall

not extend higher than the top of the permanent metal form.

Form supports at steel beam or girder bridges shall be placed in direct contact with

the top flange of the beam or girder and shall be adjusted to maintain the required deck

thickness. If straps are used on the top flanges, the straps shall be No. 8 gauge thick,

fit tight, and shall not be galvanized. Form supports shall not be welded to flanges of

non-weldable grades of steel or to steel flanges subject to tensile stresses.

640

Form supports at prestressed concrete I-beam, prestressed concrete spread box

beam, and prestressed concrete bulb-T beam bridges shall be placed in direct contact

with the sides of the box or edge of the I-beam or bulb-T beam flange and shall be

adjusted to maintain the required deck thickness. The form supports may be attached

to steel inserts cast into the top of the box, I-beam, bulb-T beam, straps extending

across the top of the flange, hangers mechanically attached to reinforcing bars

extending from the top flange, or by other approved methods. If straps are used across

the top flange, they shall be No. 8 gauge thick, fit tight, and shall not be galvanized.

Attachments shall not be welded directly to beam reinforcement. In addition, the use

of recesses cast into the beam to serve as form supports will not be allowed.650

All permanently exposed form metal, where the galvanized coating has been

damaged, shall be thoroughly and satisfactorily cleaned, wire brushed, and painted

702.13

633

with two coats of zinc oxide-zinc dust primer in accordance with Federal Specification

MIL-P-2441, Type II, with no color added. Minor heat discoloration in areas of welds

need not be touched up.

Concrete shall be placed in accordance with 702.20. Particular emphasis shall be

placed on proper vibration of the concrete to avoid honeycombs and voids, especially

at construction joints, expansion joints, attachment hardware, and valleys and ends of660

form sheets. Pouring sequences, procedures, and mixes shall be submitted for

approval.

If it is determined that the procedures used during the placement of the concrete

warrant inspection of the underside of the deck, at least one section of the forms shall

be removed at a location and time selected for each span in the contract. This is to be

done as soon after placing the concrete as practical to provide visual evidence that the

concrete mix and the procedures are obtaining the desired results. An additional

section shall be removed if it is determined that there has been any change in the

concrete mix or in the procedures warranting additional inspection.670

After the deck concrete has been in place for a minimum of two days, the concrete

shall be tested for soundness and bonding to the forms by sounding with a hammer as

directed. If areas of doubtful soundness are detected by this procedure, the forms shall

be removed from such areas for visual inspection after the pour has attained adequate

strength. This removal of the permanent metal bridge deck forms shall be with no

additional payment. At locations where sections of the forms are removed, form

replacement will not be required, but the adjacent metal forms and supports shall be

repaired to present a neat appearance and ensure their satisfactory retention. As soon

as the form is removed, the concrete surfaces will be examined for cavities,680

honeycombs, and other defects. If irregularities are found, and it is determined that

these irregularities do not justify rejection of the work, the concrete shall be repaired

as directed and shall be given a finish in accordance with 702.21. If the concrete where

the form is removed is unsatisfactory, additional forms, as necessary, shall be removed

to inspect and repair the slab, and the methods of construction shall be modified as

required to obtain satisfactory concrete in the slab. All unsatisfactory concrete shall be

removed or repaired as directed.

The amount of sounding and form removal may be moderated as directed after a

substantial amount of slab has been constructed and inspected, if the methods of690

construction and the results of the inspections as outlined above indicate that sound

concrete is being obtained throughout the slabs. All necessary facilities shall be

provided for the safe and convenient performance of inspection procedures.

The forms for any portion of the structure shall not be removed until the concrete

is strong enough to withstand damage. If field operations are not controlled by beam

702.13

634

or cylinder tests, the following periods, exclusive of days when the ambient700

temperature is below 40°F, for removal of forms and supports may be used as a guide.

Centering under beams ....................................................... 15 days

Roadway Slabs ................................................................... 7 days

Walls, Columns, Sides of Beams, and all other parts ......... 12 h

If high-early strength cement is used, these periods may be reduced as directed. If

portland-pozzolan cement, types IP or IP-A, fly ash or slag cement is used in the

structural concrete as a pozzolan, these periods shall not apply and the removal of

forms and supports shall be controlled by test beams in accordance with 702.13(h).710

To obtain a satisfactory surface finish, forms for railings, parapets, and exposed

vertical surfaces shall be removed no less than 12 h and no more than 48 h after the

concrete is placed, depending on weather conditions.

Copings, corners, and projections shall not be cracked or injured during the

removal of the forms. If damage occurs, the amount of concrete adjacent to the

damaged portion shall be removed and replaced as directed with no additional

payment.

720

The shape, strength, rigidity, water-tightness, and surface smoothness of re-used

forms shall be maintained at all times. Any warped or bulged lumber shall be re-sized

before being used. Unsatisfactory forms shall not be used.

When portland-pozzolan cement, types IP or IP-A, is incorporated into the

structural concrete elements listed below, when fly ash or slag cement is incorporated

into the structural concrete elements listed below, or when field operations are being

controlled by beam tests, the removal of forms will be allowed when the modulus of

rupture reaches or exceeds the following values:730

Concrete Use Required Flexural Strength, psi,

Dead Load Only

Girders, Arches, and similar units 390

Interior Bent or Pier Caps 480

The beams will be cured under the same conditions as the concrete which they

represent. Beams will be tested for flexural strength as simple beams with third-point

loading in accordance with 505.

702.14Falsework and Centering

Detailed working drawings for falsework and arch centering shall be submitted in

accordance with 105.02. Since the quality of the lumber is not known and because of

the uncertainty of computing nailed joints, no responsibility will be assumed by the740

Department for the strength of falsework and centering.

702.14

635

Working drawings for falsework shall include details for support of interior bent

caps, hammerhead piers, and the portion of the bridge floor and coping beyond fascia

girders or beams if the overhang is 18 in. or more, or if a finishing machine, concrete

spreader, or other equipment is to be supported by the overhang.

The scheme of falsework for work on a span over active railroad tracks shall

provide a minimum horizontal clearance of 13 ft from the centerline of the nearest

tangent track or 14 ft from the centerline of the nearest track on a horizontal curve and750

a minimum vertical clearance of 22 ft from the top of the highest track rail unless

different clearance values are approved by the railroad.

Falsework shall be designed and constructed to safely carry the full load applied

with a minimum settlement and deflection and with sufficient camber to counteract

unavoidable shrinkage, deformation, and settlement. Structures shall have a permanent

camber only when shown on the plans and the falsework shall be set to provide it.

For designing falsework and centering, a weight of 150 lb/cu ft shall be assumed760

for plastic concrete. A live load allowance of 50 lb/sq ft shall be added for horizontal

projections of surfaces. All beams supporting plastic concrete shall be designed so that

there are no appreciable deflections under full load. The beams shall be considered as

being unsupported by knee-bracing, such bracing to be considered as relieving sagging

and bending only. The use of inclined columns, where properly braced, will be

allowed.

The unsupported lengths of wooden columns and compression members shall not

exceed 30 times the dimensions of the least side, or 30 times the least diameter.

770

Unit stresses in timber shall not exceed the following:

For Douglas fir, white oak, long-leaf yellow pine:

Bending................................................... 1,800 psi

Columns.................................................. 1,800 (1-L/60D) psi

For spruce, cypress, short-leaf pine, white pine, western hemlock:

Bending................................................... 1,500 psi

Columns.................................................. 1,500 (1-L/60D) psi

780

In the above:

L = length of column in inches

D = least diameter or least dimension in inches.

Hardwood wedges may be required to take up any settlement in the falsework,

either before or during the placing of concrete.

702.14

636

Arch centering shall be constructed to enable it to be lowered or released gradually

and uniformly after pouring arch ribs and rings. Lagging for arch centering shall be of

uniform thickness. Unless otherwise specified, the nominal thickness shall be no less790

than 2 in. A smooth surface shall be produced on the undersides of arch rings. The

upper sides of all lagging shall be oiled before concrete is placed.

Unless driving of piles for falsework bents is precluded by soil or other special

conditions or unless otherwise specified, all bents for falsework shall have driven piles.

These shall be driven to support the required loads without settlement, spacing, and

subsequent removal shall be satisfactory.

If permission is given to place frame bents, they shall be placed on continuous

concrete mudsills, or as approved.800

Unless otherwise specified, the following shall apply to the removal of falsework

and centering:

by beams or girders shall remain in place at least seven days

after concrete placement and until attaining or exceeding 480

psi flexural strength. Operations on the slab may continue after

achieving the required flexural strength. No additional concrete810

shall be cast until the falsework has been released.

including the bridge deck overhang shall remain in place at least

three days after concrete placement and until attaining or

exceeding 480 psi flexural strength. Falsework jacks may be

loosened, but not removed, and operations may continue on

overhangs three days after concrete placement and achieving

the required flexural strength. Falsework jacks may be removed

after seven days.820

pier caps, shall remain in place at least three days after concrete

placement and until attaining or exceeding 480 psi flexural

strength.

shall not be released from any one span until the adjacent and

spandrel walls have cured for the required time and the next

adjacent arch ring has been poured for at least 48 h.830

girder units shall not be released from any span until the entire

702.14

637

continuous unit has been completed and all concrete cured for

the required period.

November, or any time between April and October when the

average temperature is less than 50°F, the above periods shall

be increased 20%. For concrete poured during December,840

January, and February, they shall be increased 40%.

to take the stresses, due to its own weight, uniformly and

gradually.

Permission for removal may be refused if it is determined that

there may be resulting damage to the structure.

850

702.15Joints

Construction joints shall be located across regions of low shearing stress and, so

far as possible, where they are hidden from view in the finished structure. They shall

be made only where shown on the plans, unless otherwise specified.

Placing of concrete shall be continuous between construction joints. If placing is

interrupted and a construction joint becomes necessary, provisions shall be made for

interlocking with the preceding layer by constructing raised keyways as shown on the860

plans or as directed.

When fresh concrete is intended to be joined to concrete that has already set, the

surface of the in-place concrete shall be cut with a suitable tool to remove all loose

and foreign material. The cut surface shall then be scrubbed with wire brooms and

kept wet until the new concrete is placed thereon. Immediately before the new concrete

is placed, the forms shall be drawn tight against the in-place concrete and the exposed

surface of the concrete shall be coated with a thin coating of mortar composed on one

part cement and two parts No. 23 sand.

870

All concrete for slabs, beams, girders, cantilevered brackets, and footings shall be

placed in one continuous operation to form monolithic construction. However, if,

because of rain or other unavoidable reasons, concreting is interrupted where

monolithic construction is required, the concrete shall be kept plastic by placing

frequent small batches until this part of the work is completed or until normal

operations can be resumed. If the interruption is such that even partial operations

cannot be carried on and construction joints are unavoidable, the joints shall be made

in planes exactly normal to the main reinforcing bars and only where the shear is at a

702.15

638

minimum. In simply supported slabs, beams, and girders, such regions of minimum

shear are at or near the center of the span.880

Unless otherwise provided, pours in all abutments for an arch bridge shall be

continuous from the top of footing to the skewback. If it is advisable to pour only a

portion of the abutment at one time, a vertical construction joint may be placed parallel

to the major reinforcement of the arch ring with written permission.

Horizontal construction joints will not be allowed in footings. If there is a

probability that the entire amount of concrete cannot be poured monolithically, vertical

or other construction joints shall be provided as directed.

890

Horizontal construction joints in the shafts of reinforced piers, retaining walls,

and abutments, other than abutments for arch bridges, may be made only if approved.

Where such joints show on an exposed surface, special care shall be taken to make the

joints truly straight, clean, and watertight. To avoid visible joints so far as possible on

exposed faces, the top surface of the concrete shall be finished to the underside of a

strip nailed to the form work for the exposed surface of the concrete, the strip to be

placed as directed. If such a horizontal joint intersects any coping or any sloping

surface where a featheredge would be formed, an inclined bulkhead shall be placed to

make the joint normal to the sloping surface for a distance of no less than 6 in. or, if

there is a coping, no less than the depth of the coping. Horizontal construction joints900

will not be allowed in the stems of concrete T-beams or at the junction of T-beam

stems and flanges.

Bridge expansion joints shall be of the form, dimensions, material, and design

shown on the plans. Open expansion joints shall be completely open for the

dimensions specified and for their entire length. Preformed expansion joint filler shall

be placed true and even and with abutting sections pressed together tightly. The

material shall be of the size shown on the plans and shall be in accordance with 906.03.

910

These joints shall be free from kinks and watertight. At bends, the strip shall be

one piece if possible. Unless otherwise shown on the plans, the joints shall be soldered.

Copper shall be in accordance with 910.16. Lead sheets shall be no less than 1/8 in.

thick.

The surface of the supporting concrete for a sliding joint shall be troweled to a

smooth finish and then covered with the required thickness of bituminous material, or

otherwise treated if so designated.920

Polychloroprene joint membrane used for semi-integral end bents shall be secured

to the concrete with an adhesive. The polychloroprene joint membrane shall be

702.15

639

centered vertically on the joint and shall have no gaps. Any field joint in the

polychloroprene membrane shall be lapped a minimum of 12 in.

702.16Drainage Pipes Through Concrete Masonry

At all enclosures where water could not otherwise escape through the concrete,

drainage pipes shall be installed as shown on the plans. Before fill is placed around930

these pipes, geotextile for use with underdrains shall be placed over the drain pipe and

securely held in place. Loose stone shall be laid by hand over the inlet end to provide

a cover sufficient to retain the fill and enable free drainage. Drains through abutments

and retaining walls shall be placed with a slight incline downward towards the exposed

face.

702.17Encased Pipes and Conduits

Pipes and conduits to be encased in the concrete shall be installed before the

concrete is placed. No direct compensation will be made for the installation of the

pipes and conduits. No deduction in concrete quantities will be made for the volume940

occupied.

702.18Roadway Surface Drainage

Drainage grates and basins, necessary fittings, and connections to drainage pipes

shall be placed as shown on the plans or as directed.

702.19Pouring Bent Caps

Caps shall not be poured on end bents or on any other bents falling within the

limits of the approach grade until the fill material has been placed.

950

702.20Placing Concrete

Concrete shall not be placed until forms and reinforcing bars have been checked

and approved. The forms shall be clean of all debris before concrete is placed. The

method and sequence of placing concrete shall be approved.

Where concrete floor slabs are to be poured, walkways shall be provided to protect

reinforcement from pedestrian traffic. Before placing concrete, continuous walkways

shall be placed parallel to the section of floor to be poured and shall remain in place960

until after the concrete is placed and hardened sufficiently to avoid any damage.

Walkways shall be constructed to not come in contact with the reinforcement and shall

be of sufficient width to allow finishing operations to be conducted entirely from the

walkway.

Except as otherwise directed, concrete shall be placed in horizontal layers of no

more than 24 in. thick. When less than a complete layer is placed in one operation, it

shall be terminated by a vertical bulkhead. In order to avoid planes of separation

between the layers and damage to the plastic concrete beneath, each layer shall be

placed and consolidated before the preceding layer has taken initial set. On horizontal970

702.20

640

surfaces and at horizontal construction joints, the forms shall be overfilled

approximately 1/2 in. and then struck off to the required elevation prior to the initial

set of the concrete.

When placing is temporarily discontinued and as soon as it becomes firm enough

to retain its shape, the concrete shall be cleaned of all laitance and other objectionable

material to a depth sufficient to expose sound concrete. Unless otherwise authorized,

depositing concrete shall not be discontinued within 18 in. of the top of a face.

However, if provisions have been made for a coping of less than 18 in. thick, a

construction joint may be made at the underside of the coping.980

Where new concrete is to abut existing concrete, the existing concrete surfaces

and existing exposed reinforcement shall be cleaned free of dust, chips, and water.

Epoxy resin adhesive, in accordance with 909.11, shall be used to coat the existing

concrete surfaces. The epoxy coating shall be tacky at the time that the new concrete

is placed. If the epoxy coating has cured beyond the obvious tacky condition, it shall

be reapplied prior to placing the new concrete.

After initial set of the concrete, the forms shall not be jarred and no strain shall be

placed on the ends of projecting reinforcement.990

The external surface of all concrete shall be worked thoroughly, during placing,

by means of tools of an approved type. The working shall be such as to force all coarse

aggregate from the surface and to bring mortar against the forms to produce a smooth

finish substantially free from water and air pockets or honeycomb.

Concrete shall be placed to avoid segregation of the materials and the

displacement of the reinforcement. Where steep slopes are required, the chutes shall

be equipped with baffle boards or be in short lengths that reverse the direction of1000

movement. Open troughs and chutes shall extend as nearly as possible to the point of

deposit. Equipment made of or coated with aluminum alloys shall not be used to

transport concrete. Pumping of concrete shall be in accordance with 702.10. When the

discharge needs to be intermittent, a hopper or other device for regulating the discharge

shall be provided. Placement of supplementary bins or hoppers may be ordered above

the point where concrete is being deposited. The concrete shall be allowed to

accumulate in these containers in considerable quantity and shall be discharged

immediately through pipes extending from the bottoms of these bins or hoppers. All

chutes, troughs, and pipes shall be kept clean and free from coatings of hardened

concrete. The water used for flushing shall be discharged clear of the concrete already1010

in place.

Concrete shall not be dropped in the forms a distance of more than 5 ft except

when confined by closed chutes or pipes. Each part of the form shall be filled by

depositing the concrete as near final position as possible. The coarse aggregate shall

be worked back from the forms and worked around the reinforcement without

702.20

641

displacing the bars. After initial set of the concrete, the forms shall not be jarred and

no strain shall be placed on the ends of projecting reinforcement.

Unless otherwise directed, the concrete shall be compacted with mechanical

vibrators operating within the concrete. When required, vibrating shall be

supplemented by hand spading with suitable tools to ensure proper and adequate

compaction. Vibrators shall be of an approved type and design, adequately powered

and capable of transmitting 10,800 impulses per minute in air. The diameter of the

head of the vibrator shall be 1 1/4 to 2 1/2 in. Vibrators shall be manipulated so that

the concrete is thoroughly worked around the reinforcement and imbedded fixtures

and into corners and angles of the forms. Vibrators shall not be used as a means to

cause concrete to flow or run into position in lieu of placing. The vibration at any point

shall be of sufficient duration to accomplish compaction but shall not be prolonged to1030

the point where segregation occurs. Vibrators shall not be attached to or allowed to

contact forms or reinforcement or to penetrate beyond any layer of fresh concrete.

No concrete except for foundation seals shall be deposited under water, without

written permission. If such permission is granted, care shall be exercised to prevent

the formation of laitance. Concrete shall not be deposited until any laitance, which

may have formed on concrete previously placed, has been removed. Pumping shall be

discontinued while depositing foundation concrete if it results in a flow of water inside

the forms. If concrete, except for foundation seals, is deposited under water, the1040

proportion of cement used shall be increased at least 25% with no additional payment

to compensate for losses due to water. Concrete deposited under water shall be placed

in a compact mass in its final position by means of a tremie, a closed bottom dump

bucket, or other approved method and shall not be disturbed after being deposited.

A tremie shall consist of a tube having a diameter of no less than 10 in. and

constructed in sections having flanged couplings fitted with gaskets. Support of the

tremie shall be such that it enables free movement of the discharge end over the entire

top surface of the area on which the concrete is to be deposited and allows rapid

lowering, when necessary, to retard or stop the flow of the concrete. The discharge end1050

shall be kept closed until immediately prior to depositing in order to prevent water

entering the tube and shall be completely sealed except when concrete is actually being

deposited. The tremie tube shall be kept full to the bottom of the hopper. When a batch

is dumped into the hopper, the flow of concrete through the tube shall be started by

slightly raising the discharge end, but always keeping it in the previously deposited

concrete. The flow shall be continuous until all the required concrete is deposited.

Except as otherwise provided for a foundation seal, footing concrete shall not be

placed except when the cofferdam is dewatered and so maintained during placement.1060

702.20

642

If it is necessary to operate the pump while placing footing concrete, or

immediately thereafter, the seepage water shall be conducted to a sump at the pump

intake in such manner that it does not flow over the fresh concrete. Special care shall

be taken to prevent pumping cement out of the fresh concrete.

Footing concrete may be placed directly against sheet piling of the cofferdam

when shown on the plans or authorized in writing. Where class X excavation has been

extended beyond established neat lines of a footing, the bottom 12 in. of such footing

shall be poured to the actual limits of the excavation. When necessary, the foundation1070

material on which the footing is to rest shall be protected from freezing. Where an

existing structure is to be extended, the existing footings shall be protected from

damage. Damaged footings shall be repaired as directed with no additional payment.

Piling, if any, shall be driven to or cut off at the proper elevation to enable

embedment in the footing concrete equal to that shown on the plans. All laitance or

other unsatisfactory material shall be removed from the exposed surface of the

concrete in place by some means which does not injure the concrete. If a footing is to

be constructed on a foundation seal, it shall be to the dimensions shown on the plans

and, if necessary, the height of the shaft adjusted to bring the bridge seat to the required1080

elevation.

Placing concrete in footings shall start at one end of the footing and be continued

until the surface of the concrete is brought to the elevation of the top of the footing.

The concrete shall be allowed to work forward, displacing any water with as little help

as possible. The concrete shall not be dragged through or shoveled into water or

deposited into running water. Placing concrete in more than a few inches of water shall

be done only with written permission.

A foundation seal may be required by the plans, as requested, or as directed. When

required by the plans, the seal shall be constructed to the size shown, or as specified

in writing. Where adverse dewatering conditions are encountered as described in

206.09, a foundation seal may be required to be placed to the necessary dimensions

If a foundation seal is requested, written permission shall be obtained before

starting such work. If approval is given, the seal shall be placed to designated

dimensions.

Seals shall be of class A concrete having a slump in accordance with 702.12,1100

placed continuously from start to finish, and in accordance with 702.20(d). The

cofferdam shall have been vented or ported at low-water level. The seal shall be of the

thickness shown on the plans, or as requested and approved. When the seal has

hardened sufficiently to withstand the hydrostatic pressure, the cofferdam shall be

dewatered and the remainder of the structural concrete shall be placed in dry

conditions.

702.20

643

702.21Finishing Concrete Surfaces

Unless otherwise authorized, the surface of the concrete shall be finished

immediately after form removal. Only the minimum amount of covering necessary to1110

allow finishing operations to be carried on shall be removed at one time. Subject to

approval, metal ties may be left in the concrete for the purpose of supporting or bracing

subsequent work. Such ties shall be in accordance with 702.13(b) and shall be of a

type which uses a cone and rod as both spreader and tie. Before final acceptance of the

work, the cones shall be removed and the cavities filled, in accordance with 702.13(b).

All concrete surfaces shall be given a finish immediately following the removal

of any forms.

At the time of the removal of forms, the concrete surface shall be scraped to1120

remove all fins and irregular projections. The surface shall then be power ground to

smooth all joints and chamfers.

After grinding is completed, a paste of grout shall be applied to the concrete

surface with a sponge float to fill all air holes and small irregularities. The paste grout

shall be six parts of pre-mix mortar mix for masonry and one part white portland

cement in accordance with ASTM C150, Type 1.

After the paste grout takes its initial set, the surface of the concrete shall be

scraped with a steel drywall knife to remove the paste from the surface.1130

The concrete surfaces of pier and bent caps, the front face of mudwalls, and any

other concrete surfaces specified shall be sealed. The material used for sealing shall

be in accordance with 709. It shall be applied to obtain a finished film thickness of at

least 10 mils. Mixing, surface preparation, and method of application shall be in

accordance with the manufacturer’s recommendations. However, the surfaces to be

sealed shall be prepared in accordance with 709 prior to applying the sealer.

702.22Curing Concrete

Concrete in bridge decks or the top surface of reinforced concrete slab bridges1140

shall be cured continuously 24 h per day for a minimum of 168 h commencing

immediately after the surface is able to support the protective covering without

deformation. Water curing in accordance with 702.22(a) shall be initiated within 60

minutes after the finishing machine completes the final strike-off of any portion of the

concrete surface. Curing or other protective efforts which may include the use of

evaporative retardants shall begin sooner if adverse conditions exist. Adverse

conditions include, but are not limited to, high winds, extreme temperatures, or low

humidity. A work bridge shall be used following the finishing machine to facilitate the

placement of curing materials, if necessary. Curing time for bridge decks and the top

surface of reinforced concrete slab bridges are not controlled by beam tests and the1150

cure time shall not be reduced. In addition to the minimum of 168 h cure period, curing

shall continue until a flexural strength of 550 psi has been attained. Curing of patches

or small full depth deck replacement areas on existing bridge decks that are to be

702.22

644

overlaid, may be controlled by test beams in accordance with 702.24(a).

Unless otherwise specified, all other concrete shall be cured continuously 24 h per

day for at least 96 h commencing immediately after the surface is able to support the

protective covering without deformation. In addition to the required hours, curing shall

continue until the flexural strength stated in 702.13(h) and 702.24 has been attained.

1160

Where it has been determined that a surface treatment is to be used, the membrane

forming curing compound shall not be used. Membrane forming curing compound

shall not be used on bridge decks nor on reinforced concrete slab bridges.

The curing of surfaces to be waterproofed may be discontinued when

waterproofing is started.

If further precautions are necessary to ensure strength, they shall be taken as

directed.

1170

Surfaces to be cured shall be protected and kept continuously and thoroughly wet

during the curing period. Curing shall consist of pre-wetted burlap underneath a layer

of white plastic sheeting with a network of soaker hoses. Other wet curing systems

including engineered mats or blankets shall be submitted to the Engineer for approval

at least 14 days prior to use. Burlap shall be free of contamination and shall be prepared

by soaking in clean water for at least 2 h before beginning concrete placement. New

burlap shall be soaked at least 12 h prior to use. Immediately before use, the burlap

shall be draped or suspended vertically to remove excess water that may dilute or

damage plastic concrete. Soaker hoses shall be placed after the concrete is hard enough1180

to walk on without deformation. The protective covering shall be suitably anchored to

keep the protective materials in place during the curing period. Curbs, walls, handrails,

copings, and other surfaces requiring a finish in accordance with 702.21 may have the

covering temporarily removed for finishing, but the covering shall be restored as soon

as possible.

All surfaces shall be given the required surface finish prior to application of the

curing compound. During the finishing period, the concrete shall be protected by the

water curing method.1190

The curing compound shall be mixed thoroughly within 1 h before use. The

application shall be a minimum spreading rate of 1 gal. of liquid coating for every 150

sq ft of concrete surface. Curing compound shall be applied to provide a uniform,

solid, white opaque coverage on all surfaces, similar to a white sheet of paper. All

concrete cured by this method shall receive two applications of the curing compound.

The first application shall be applied immediately after stripping of forms and

acceptance of the concrete finish. If the surface is dry, the concrete shall be wetted

with water and the curing compound applied just as the surface film of water

702.22

645

disappears. The second application shall be applied after the first application has set.1200

During curing operations all unsprayed surfaces shall be kept wet with water.

The coating shall be protected against marring for at least 10 days after

application. All coatings marred or otherwise disturbed shall be given an additional

coating. If the surface coating is continuously subjected to injury, immediate

application of water curing may be required. If the use of a curing compound results

in a streaked or blotchy appearance, the method shall be stopped and water curing

applied until the cause of the defective appearance is corrected.

702.23Waterproofing1210

The expansion joint shall be waterproofed on the following:

The inside face of spandrel walls and extrados of arches shall be waterproofed.

1220

A firmly bonded membrane consisting of two layers of dry fabric and three

applications of waterproofing material, shall be placed at all expansion joints set out

herein. One uncoated layer of fabric shall not touch another layer or the concrete at

any point. There shall be at least three complete and separate applications of the

waterproofing material. The application shall be sufficiently heavy to conceal the

weave in the fabric. Sufficient fabric shall be placed in V-strips at the joints to enable

the movement of adjacent sections of concrete without tearing the fabric. The

membrane shall be carefully flashed at all exposed edges and laps sealed down

thoroughly. Waterproofing shall be planned so that, at the close of work each day, all

fabric placed shall have received the final application of waterproofing material.1230

Concrete surfaces to be waterproofed shall be reasonably smooth and free from

projections and holes. Immediately before the application, the surface shall be cleaned

of dust and loose materials. Waterproofing shall be done only when the surface is at

least dry enough to prevent the formation of steam when the hot material is applied.

When the air temperature is below 35°F, waterproofing shall not be done, unless

otherwise specified.

The material shall be applied to cover the area completely. If necessary, more than

one coat shall be applied to secure a satisfactory coating and proper adhesion. Coating1240

and fabric shall stop a uniform distance below the top surfaces of walls. The material

shall not be splattered over surfaces or faces of concrete which subsequently are

exposed in the finished structure. Utility asphalt for waterproofing shall be heated to a

temperature of between 300°F and 350°F. The material shall be stirred frequently to

702.23

646

prevent local overheating. The waterproofing material shall not be damaged when

backfill is placed against a waterproofed joint.

702.24Application of Loads to and Acceptance of New Concrete

Except as otherwise hereinafter provided, application of loads to new concrete

shall be in accordance with the following:1250

beams representing all concrete required to carry live loads have

attained a flexural strength of 550 psi for third-point loading.

representing the concrete required to resist it have attained a flexural

strength of 440 psi for third-point loading. The unbalanced height

shall not exceed 10 ft until test beams representing the concrete have

attained a flexural strength of 480 psi for third-point loading.1260

be placed on concrete until test beams representing the concrete have

attained a flexural strength of 400 psi for third-point loading. A dead

load shall not be placed on hammer-head piers until test beams

representing the concrete have attained a flexural strength of at least

480 psi for third-point loading. The concrete floor, if to be placed

thereon, shall not be poured until test beams representing the

concrete supporting the superstructure have attained a flexural

strength of at least 440 psi for third-point loading.1270

falsework shall attain a flexural strength of a minimum of 480 psi

for third-point loading, before a dead load of concrete is applied.

are used in bridge railings or concrete barrier and the temperature

limitations in accordance with 702.05 are not met, the bridge railings

or concrete barrier may be put into service when flexural strength

testing performed on test specimens indicate a modulus of rupture1280

of 500 psi has been attained.

No time extension will be considered for delays due to time necessary to attain

specified strengths.

Beams will be prepared and tested in accordance with 702.13(h). Before traffic is

allowed over a concrete structure built to be under fill, it shall be covered with 9 in. or

more of earth or other suitable material, or otherwise protected. All other structures

shall be properly protected against impact or other damage.

1290

702.24

647

When compressive strength is used as a basis for acceptance of concrete, for

determining when a latex modified concrete overlaid bridge deck may be opened to

traffic, for determining form removal time, or for determining when a structure may

be put into service, standard specimens shall be made and cured in accordance with

ASTM C31 and shall be tested in accordance with ASTM C39. Strength requirements

shall be in accordance with ASTM C94, with the exception that the strength shall be

the average of the strengths of all cylinders tested at the age specified, with a minimum

of two cylinders. This average shall be equal to or greater than the required strength.

If the compressive strength of one or more cylinders in a strength test is below 75% of

the required strength, the entire test will be considered as failed.1300

Failure to meet the strength requirements will be cause for rejection of the quantity

of concrete represented by the cylinders. All molds, facilities, and materials necessary

to prepare and cure the specimens shall be furnished with no additional payment.

702.25Field Drilled Holes in Concrete

This work shall consist of field drilling holes of the diameter and length shown on

the plans or as directed.

When vertical holes are to be drilled into the top of a concrete bridge deck, a1310

minimum clearance of 2 in. shall be maintained between the bottoms of holes and

bottom of slab. When vertical holes are to be drilled over a steel beam flange, the holes

may be extended to the top of the beam flange. When vertical holes are to be drilled

over a concrete I-beam, concrete box beam, concrete bulb-T beam, or concrete girder,

the depths of the holes shall be as shown on the plans. If breakout occurs on the bottom

of slab during the drilling process, the work shall be stopped, the breakout shall be

repaired as directed, and an approved alternate drilling method shall be used to prevent

breakout.

When grouted holes are specified, the diameter and length of the holes shall be in1320

accordance with the grout manufacturer’s recommendations.

702.26Artificial Lighting

No portion of the work which cannot be finished during daylight hours shall be

started unless written permission is given, in which case adequate lighting shall be

provided and maintained.

702.27Method of Measurement

Concrete will be measured by the cubic yard in accordance with the neat lines

shown on the plans or as directed. No deductions will be made for the volume of joint1330

material, embedded reinforcement, encased piles, or for a pipe with an area of less

than 1 sq ft.

Cast iron grates, basins, and fittings will be measured by the number of complete

assemblies installed. Drainage pipe through concrete masonry will be measured in

702.27

648

accordance with 715. Field drilled holes will be measured by the number of holes

drilled.

Concrete in railings will be measured in accordance with 706.07. Reinforcing bars

will be measured in accordance with 703.07.1340

702.28Basis of Payment

The accepted quantities of structural concrete will be paid for at the contract unit

price per cubic yard of concrete, for the class and use specified. Cast iron grates,

basins, and fittings will be paid for at the contract unit price per each assembly,

complete in place. Steel drain pipe will be paid for at the contract lump sum price.

Field drilled holes in concrete will be paid for at the contract unit price per each.

Concrete in railings will be paid for in accordance with 706.08. Reinforcing bars

will be paid for in accordance with 703.08. Drainage pipe through concrete masonry1350

will be paid for in accordance with 715.

If a foundation seal is constructed as shown on the plans, it will be paid for at the

contract price per cubic yard for concrete, foundation seal. If ordered to be done, or

allowed to be done, payment will be made at a unit price per cubic yard equal to 75%

of the contract unit price per cubic yard for class B concrete in footings. The

excavation for the foundation seal will be paid for at the contract unit price per cubic

yard for the class of excavation specified for the footing. Unless otherwise provided,

the pay quantity for excavation for foundation seal will be equal to the theoretical

volume bounded by the bottom of the proposed footing, the bottom of the approved1360

excavation, and vertical planes 18 in. outside the neat line of the footing and parallel

thereto, regardless of the quantity actually removed. If design of the structure requires

sheeting to be outside these limits, the limits will be extended to 6 in. beyond the neat

lines required by the design of the structure. If the Contractor chooses to construct a

rectangular cofferdam around a U-shaped abutment in lieu of following the outline of

the footing, the maximum allowable increase in the pay quantity above the theoretical

shall not exceed 25%. The pay quantity for the foundation seal will be equal to the

excavation volume described above.

Payment will be made under:1370

Pay Item Pay Unit Symbol

Concrete, A, Substructure.......................................................... CYS

Concrete, A, Superstructure....................................................... CYS

Concrete, B, Above Footings .................................................... CYS

Concrete, B, Footings ................................................................ CYS

Concrete, C, ____ ...................................................................... CYS

use

Concrete, Foundation Seal......................................................... CYS1380

Field Drilled Hole in Concrete .................................................. EACH

Grates, Basins, and Fittings, Cast Iron ...................................... EACH

702.28

649

The cost of forms, PVC for bridge floor drains, falsework, falsework piling,

centering, expansion joints, preformed expansion joint filler, waterproofing, curing,

finishing, and necessary incidentals shall be included in the cost of the pay items. The

cost of placing epoxy resin adhesive on existing concrete surfaces shall be included in

the cost of new concrete which abuts the existing concrete. Payment for concrete used

in footings in class X excavation will be made at the contract unit price only for the

cubic yards placed within the neat lines of the footings as shown on the plans or as1390

revised.

If the Contractor elects to increase the cement content as allowed herein, no

additional compensation will be made.

The cost of permanent metal forms shall be included in the cost of concrete, C,

superstructure. The pay quantity of concrete in the slab will be computed from the

dimensions shown on the plans, with no allowance for form deflection or geometry.

Elastomeric bearings will not be paid for directly, unless otherwise specified. The1400

cost thereof shall be included in the cost of the structural member they support. The

cost of protecting existing footings to be extended shall be included in the cost of

concrete, B, footings, unless otherwise specified.

The cost of grout for grouting reinforcing bars in place, the length of grouted hole

recommended by the grout manufacturer in excess of the length shown on the plans,

and the additional length of reinforcing bars required shall be included in the cost of

field drilled hole in concrete.

The cost of furnishing and installing polychloroprene sheeting shall be included1410

in the cost of concrete, A, substructure.

The cost of high density plastic bearing strips shall be included in the cost of

concrete, A, substructure.