723REINFORCED CONCRETE THREE-SIDED STRUCTURES

723.01Description

This work shall consist of constructing a reinforced concrete three-sided arch- topped structure or structure extension with headwalls and wingwalls, a reinforced concrete three-sided flat-topped structure or structure extension with headwalls and wingwalls, or a reinforced concrete true ar ch shape structure or structure extension with spandrel walls and wingwalls in accordance with 105.03. The reinforced concrete three-sided structure, structure extension, headwalls, wingwalls, footings, and spandrel walls may be precast or cast-in-place. 10

The Contractor may be allowed to substitute a box structure in accordance with 714 which shall be subject to a revision of the waterway permits and shall be as approved by the Engineer.

MATERIALS

723.02Materials

Materials shall be in acco rdance with the following:

Chemical Anchor System ............................................ 901.05 Coarse Aggregates, Class A or Higher, Size No. 91 ... 904.03 Epoxy Coated Reinfo rcing Bars .................................. 910.01(b)9 Geotextile .................................................................... 918.02 Hydrated Lime ............................................................. 913.04(a) Joint Membrane for Precast Reinforced Concrete Box and Three-Sided Structure Sections .................. 907.07 723.01

Masonry Ceme nt ......................................................... 901.01(c) 30 Mortar Sand ................................................................. 904.02(e) Natural Sand ................................................................ 904.02(a) Non-Epoxy PCC Sealer ............................................... 909.10 Portland Ceme nt .......................................................... 901.01(b) Precast Reinforced Concrete Headwalls, Wingwalls, Footings, and Spandrel Walls ............ 907.06 Precast Reinforced Concrete Structure Sections ......... 907.05 Preformed Flexible Joint Sealant ................................. 907.11(a) Reinforcing Bars .......................................................... 910.01 Riprap .......................................................................... 904 40 WWR, Smooth a nd Deformed..................................... 910.01

Cast-in-place concrete for a reinforced co ncrete three-sided structure, or splices between an existing culvert structure and a precast reinforced concrete three-sided structure extension shall be class A or higher in accordance with 707.04(c). It shall have a 28-day minimum concrete compressive strength of 5,000 psi. Cast-in-place concrete for headwalls, wingwalls, or spa ndrel walls shall be class A or higher in accordance with 707.04(c). It shall have a 28-day minimum concrete compressive strength of 4,000 psi. 50

When the Contractor elects to provide a cast-in-place structure, acceptance of the structure will be based on tests for relative yield, air content, slump, water/cementitious ratio, and compressive strength. Relative yield and air content shall be in accordance with 702.05. The slump and concrete temperature shall be in accordance with 707.04(c). The amount of time from the introduction of mixing water to the cement and aggregates to the completion of the discharge of the concrete shall not exceed 90 minutes. The water/cementitious ratio shall be in accordance with

707.04(d). The 28-day compressive strength shall be equal to or greater than the

specified concrete compressive strength an d otherwise shall be in accordance with 60

(c)3. The Contractor shall provide the necessary 6 in. diameter by 12 in

cylinder molds for the Department’s use.

For plastic concrete sampling, acceptance testing procedures and casting cylinders will be in accordance with 505.01. Except for footings, concrete flexural strength or results from beam breaks will not be accepted in lieu of concrete compression cylinder test results.

Cast-in-place concrete used to seal existi ng culverts shall be class A. Cast-in-place concrete for footings and base slabs shall be class B. 70

Unless otherwise specified herein, reinforcement may consist of either reinforcing bars or WWR. If specified to be coated, WW R shall be coated with either galvanized coating or epoxy coating. Reinforcing bars shall be coated with epoxy coating. For WWR, material with minimum yield strength of 65 ksi shall be used. 723.02

Reinforcement in headwalls and pedestals shall consist of reinforcing bars and shall be epoxy coated. Reinforcement in spandrel walls shall be coated. If the structure is specified as requiring coated reinforc ement, reinforcement, including support devices, in that structure shall be coated. In lieu of coating, the support device may be 80 manufactured of a non-corrosive material.

Headwalls, wingwalls, and spandrel walls shall be connected to the outside structure sections. Wingwalls shall be connected to the spandrel walls if the structure is a true arch shape structure. Precast headwalls, precast wingwalls, and precast spandrel walls shall be connected with bolted steel plates.

CONSTRUCTION REQUIREMENTS

723.03General Requirements 90

Excavation and disposal shall be in accordance with the applicable requirements of 206. Waterproofing of the designated areas shall be in accordance with 702.23. All underground drains encountered during excavation for the structure shall be perpetuated as dictated by field conditions. Drainage openings through masonry shall be in accordance with 702.16. Handling of three-sided structures shall be in accordance with 907.05. Handling of wingwalls and spandrel walls shall be in accordance with 907.06.

For precast three-sided structures, the ma nufacturer’s representative shall provide technical instruction and on-site technical assistance to the Contractor during the 100 erection of the members.

The three-sided structure, headwalls, wingwalls, and footings shall be designed and constructed in accordance with the dimensions shown on the contract plans. Construction joints shall not be used with in the cross-section of precast three-sided structures unless shown on the contract plans.

723.04Design Requirements

A three-sided structure shall be designed for HL-93 loading in accordance with AASHTO LRFD Bridge Design Specifications. 110

The three-sided structure, headwalls, wingwalls, footings, and spandrel walls shall be designed in accordance with the soil parameters shown in the contract documents.

Headwalls, wingwalls, and spandrel walls shall be designed based on a minimum equivalent fluid pressure of 40 lb/cu ft. If flowable backfill is to be used, the Contractor shall consider the effects of hydrostatic pressure on the structure. Weep holes shall be provided in all wingwalls. Horizontal pressures shall be increased for sloping backfill surfaces and live load surcharge. Head wall connections, wingwall footings, and 120 spandrel walls shall be checked for sliding and for overturning. 723.03

A headwall with guardrail mounted on top, the anchorage of the headwall or spandrel wall to the structure section, or a moment slab with bridge railing, shall be designed for the bridge railing test level shown on the plans.

Continuity shall be established between the structure footing and the wingwall footing.

For three-sided arch-topped or true arch shape structure sections, the concrete cover over the outside circumferential reinforcement shall be a minimum of 2 in. The cover over the inside circumferential reinforcement shall be a minimum of 1 1/2 in. The clear distance of the end circumferential reinforcement shall not be less than 1 in. and no more than 2 in. from the ends of the structure section. The ends of the longitudinal distribution reinforcement shall be no more than 3 in. from the ends of the structure section.

For flat-topped structure sections, the cover dimension over the top mat of reinforcement shall be a minimum of 2 in. The cover over the lower mat of 140 reinforcement in the structure top shall be a minimum of 1 1/2 in. The cover in the legs shall be a minimum of 2 in. The clear distance of the end circumferential reinforcement shall not be less than 1 in. and no more than 2 in. from the ends of the structure section. The ends of the longitudinal distribution reinforcement shall be no more than 2 in. from the ends of the structure section.

Cover for headwall, wingwall, spandrel wall, and pedestal reinforcement shall be a minimum of 2 in. Cover for footing and base slab reinforcement shall be 3 in. for the top and sides and 4 in. for the bottom.

Reinforcement splicing and spacing sh all be in accordance with the AASHTO LRFD Bridge Design Specifications except as indicated herein. Tension splices in circumferential reinforcement shall be made by means of lapping. Where reinforcing bars are used for longitudinal distribution reinforcement, the reinforcing bars shall have a center to center spacing not to exceed 12 in. in flat-topped structure sections or 16 in. in arch-topped or true arch shape structure sections.

Where reinforcing bars are used in wingwalls, the maximum spacing for wingwall reinforcing bars shall be 18 in. for horizontal bars and 12 in. for vertical bars. 160

Exterior corner reinforcement for flat-topped structure sections shall be fully developed beyond the point where it is no longer required to resist flexure.

Working drawings shall be submitted in accordance with 105.02 for:

723.04

three-sided structure,

structure extension,

The working drawings shall include notes indicating design assumptions, applicable design codes, and material re quirements, all details, dimensions, and quantities necessary to construct the structure, headwalls, wingwalls, or spandrel walls and shall include, but not be limited to, the following information:

details, locations and details of lifting devices or inserts, locations and details of pre- or post-installed anchorages, concrete clear cover, size and spacing of reinforcing bars or WWR, and reinforcing bar bending diagrams. An analysis of the precast segment modeled as a simple span and designed in accordance with AASHTO LRFD Bridge Design Specifications Section 5.7.3. This analysis sh all demonstrate that the precast 190 segment is designed to withstand the forces of erection. Details for providing horizontal restraint of the structure legs during installation until after the completion of backfill placement shall be included unless the analysis indicates such details are not needed.

reinforcing bar sizes, reinforcing bar bending diagrams, lengths, spacings, and anchorag e details. Headwall elevation and section views shall be provided. 200

dimensions, elevations, reinforcement sizes, bending diagrams, lengths, spacings, and anchorage details. Wingwall plan, elevation, and section views shall be provided.

elevations, reinforcement sizes, bending diagrams, lengths,

spacings, and anchorage details. Spandrel wall elevation and

section views shall be provided.210

dimensions, elevations, reinforcing bar sizes, reinforcing bar

bending diagrams, lengths, and spacings indicated. Footing

723.04

799

plan and section views shall be provided. If a pile footing is

required, the pile layout shall be shown. The actual soil bearing

pressure shall be shown on the footing detail sheets.

if required.220

wingwalls.

structure.

be submitted with the working drawings where the structure

span length measured along the roadway centerline is greater230

than 20 ft, except where the height of cover is greater than 8 ft

and exceeds the perpendicular span length. The structure shall

load rate greater than 1.0 for the loading described herein or as

shown on plans. The load rating methodology shall be in

accordance with the AASHTO Manual of Bridge Evaluation

using the LRFR methodology.

723.05Manufacture

The structure sections, headwalls, wingwalls, footings and spandrel walls shall be

free of fractures. Headwalls, wingwalls, and spandrel walls shall be given a finish in240

accordance with 702.21.

The structure units shall not be stored in an upright position until the designated

handling and storage compressive strength, as shown on the working drawings, has

been achieved.

723.06Rejection

Structure sections, wingwalls, footings, or spandrel walls will be rejected due to

the following conditions.

250

single end crack which does not exceed one-half the thickness of the

section or wall,

not in accordance with this specification,

satisfactory joint.

723.06

800

723.07Repairs

Structure sections, headwalls, wingwalls, footings, or spandrel walls shall be

repaired, when necessary, due to imperfections in manufacture, handling damage, or

construction. Repairs will be acceptable if it is determined that the repairs are sound,

properly finished and cured, and if the repaired structure section headwall, wingwall,

footing, or spandrel wall is in accordance with the requirements herein.

723.08Trench Compaction270

The soils in the bottom of the excavation shall be compacted to 95% of the

maximum dry density in accordance with 203.23. If 95% of the maximum dry density

cannot be obtained in the bottom of the excavation or in other areas, the Office of

Geotechnical Services shall be contacted for additional recommendations. If during

construction, soft soils are encountered at depths that make removal impractical, the

Office of Geotechnical Services shall be contacted for additional recommendations.

723.09Footings

All footings shall be given a smooth float finish. Footing concrete shall reach a

compressive strength of 2,000 psi or flexural strength in accordance with 702.24(c)280

prior to placement of the structure sections or wingwalls. The surface shall not vary

more than 1/4 in. in 10 ft when tested with 10 ft straightedge.

An 8 in. layer of coarse aggregate No. 8 in accordance with 301 shall be placed

under the full width of the footing. Precast footings shall be made into a continuous

strip footing using closure pours between the precast units. Closure pours shall be as

detailed in the working drawings and shall be designed to accommodate the design

loads.

723.10Pedestals290

Where a reinforced concrete pedestal is required between the base of the structure

leg and the top of the footing to provide the required rise and low structure elevation

as shown on the contract plans, the Contractor shall have the option of providing a

structure with extended legs or constructing the pedestals.

723.11Placement of Structure Sections and Wingwalls

For three-sided arch-topped structures and three-sided flat-topped structures, the

structure sections shall be set on masonite or steel shims. Each wingwall that is not

precast as one unit with the footing shall be set on masonite or steel shims. A minimum

gap of 1/2 in. shall be provided between the footing and the bottom of each section or300

wingwall. Once the wingwalls or structure sections are placed, the space underneath

the wingwall or structure leg section to the top of the keyway sides shall be filled with

prepackaged grout in accordance with ASTM C1107, or conventional or self-

consolidating fine grout in accordance with ASTM C476, except as modified herein.

If conventional fine grout is used, it shall be troweled into the keyway and mounded

on one side of the leg or wingwall. The mound of conventional fine grout shall be

vibrated until it passes through to the other side of the leg or wingwall. After

723.07

801

completing this process on one side, if the conventional fine grout has not passed

through to the other side, the process shall be repeated on the other side. Conventional

or self-consolidating fine grout shall be from a prepackaged source or composed of310

one of the following mixtures:

mortar sand.

mortar sand.

with No. 23 natural sand or mortar sand.320

The maximum water/cement ratio shall be 0.446 for both conventional and self-

consolidating fine grout. An air-entraining agent from the QPL of PCC Admixtures

and Admixture Systems may be used. A Type F or Type G chemical admixture from

the QPL of PCC Admixtures and Admixture Systems shall be used in self-

consolidating fine grout to achieve the slump flow and visual stability index

requirements. Filling procedure B of ASTM C1611 will be used for measuring slump

flow. Appendix X1 of ASTM C1611 will be used for determining the visual stability

index value.

330

Acceptance of conventional fine grout will be based on an air content of 12%

±4%. Acceptance of self-consolidating fine grout will be based on tests for air content,

slump flow, and visual stability index. Air content shall be 12% ±4%. Slump flow

shall be 27 in. ±3 in. Visual stability index value shall not exceed 1. A Type C

certification in accordance with 916 shall be provided for prepackaged grout.

True arch shape structures may have grout leveling pads poured in the footing

keyways to ensure the correct seating of the true arch sections. Leveling pads shall be

approximately 2 in. thick and 16 in. long to ensure that each true arch section is resting

on approximately 8 in. of pad at each joint. The leveling pads shall be poured within340

1/8 in. of the required elevation. No loads shall be placed on the grout leveling pads

within 72 h of their placement. Masonite shims may also be used as leveling pads.

Concrete blocks of 1 1/2 in. thickness, hardwood wedges, and steel or plastic shims

shall be placed to retain the true arch sections in their proper positions until grout can

be placed in the keyway. Grout shall be consolidated in the keyway to ensure that the

entire area around the true arch section is completely filled. The grout used to construct

the leveling pads and to fill the keyways shall be in accordance with this section. Grout

shall not be placed if the air temperature is expected to be below 35°F for a period of

72 h following grout placement.

350

723.12Extension of Existing Structure

All applicable requirements of this specification shall apply to the extension of an

existing three-sided arch-topped structure with headwalls and wingwalls, a three-sided

flat-topped structure with headwalls and wingwalls, or a true arch shape structure with

723.12

802

spandrel walls and wingwalls. Such portions of the existing structure designated for

removal shall be removed. All portions of the existing structure which are to remain

in place and are damaged shall be repaired or replaced as directed. Those portions left

in place which are wholly or partially filled with debris shall be cleaned out. Material

removed shall be disposed of in accordance with the applicable requirements of

202.02.360

Before removing concrete from an existing structure with wingwalls, the

Contractor shall saw around the perimeter of the removal area on the interior and

exterior of the existing structure a depth of 1 in. All existing reinforcement in the top

slab and sidewalls exposed after concrete removal shall be cleaned and straightened in

preparation for lapping with reinforcement from adjacent new work. Where existing

reinforcement has deteriorated or been damaged during the removal operation, holes

shall be drilled into the face of the existing structure to provide embedment for

replacement reinforcing bars. The holes shall be of the diameter and depth required by

the chemical anchor system manufacturer. The holes shall be cleaned prior to placing370

the chemical anchor system and the reinforcing bars.

No concrete shall be removed from an existing structure that has a headwall but

no wingwalls. Reinforcing bars to tie the existing structure to the new structure section

shall be installed by drilling holes into the face of the existing structure to provide

embedment for reinforcing bars. The diameter and depth of the holes shall be in

accordance with the recommendations of the manufacturer of the chemical anchor

system. The holes shall be cleaned prior to placing the chemical anchor system and

the reinforcing bars.

380

An existing structure shall be extended by means of one of the following methods.

A cast-in-place concrete splice shall be constructed as a transition between the

existing structure and the precast structure extension. The splice reinforcement in the

precast structure extension section that will abut the existing structure shall be exposed

18 in. on the tongue end of the precast structure extension section. It shall be lapped

18 in. with either exposed existing structure reinforcement, in the case of an existing

structure with wingwalls, or newly installed reinforcing bars in the existing structure,

in the case of an existing structure with a headwall only as shown on the plans. Existing390

exposed structure reinforcement from an existing structure with wingwalls shall be cut

off 1 in. from the face of the new precast extension.

If the existing tongue or groove joint end is acceptable and matches the mating

joint on the new precast reinforced concrete structure extension section, the new

extension may be installed using the mating joint of the existing structure. No cutting

of the structure or splicing of reinforcement is then required. The joint between the

new precast structure extension and the existing structure shall be sealed as directed

below.

400

723.12

803

The reinforcement for the structure extension shall be lapped with the exposed

reinforcement of the existing structure as shown on the plans.

723.13Blank

723.14Precast Reinforced Concrete Three-Sided Structure Section Joints

Joints between precast reinforced concrete structure sections for three-sided arch-410

topped structures and true arch shape structures, and for flat-topped structures with

cover of 3 ft or more, may be either butt joints or keyway joints.

All butt joints shall be sealed with preformed flexible joint sealant as shown on

the plans. The sealant shall be applied once the concrete surface temperature is above

40°F or above the minimum application temperature recommended by the joint sealant

manufacturer. The concrete surfaces shall be clean and dry prior to application of the

joint sealant. Heat may be applied to the concrete surfaces until they are in accordance

with the temperature and dryness requirements.420

Joints in true arch shape and flat-topped structures shall be sealed with 1 1/2 in.

diameter preformed flexible joint sealant.

The sections of flat-topped structures with less than 3 ft of cover shall be produced

with a minimum 4 in. depth by 1 1/2 in. width keyway joint. Non-shrink grout in

accordance with 707.09 shall be placed in the keyway joint.

After sealing with preformed flexible joint sealant or non-shrink grout as directed

above, and assembly of three-sided structure sections, all butt and keyway joints

between structure sections shall be covered with a joint membrane in accordance with

907.07and centered on the joint

The exterior surface of the concrete sections shall be clean and dry before the joint

membrane is applied. The outside surfaces of the top slab and both walls of every joint

shall be completely covered for the entire length of each joint. Where joining two

sections of joint membrane material, or where two ends meet, a 3 in. overlap shall be

provided. The overlapping strip shall be firmly pressed onto the end of the underlying440

strip to seal the joint. Joints between structure sections and wingwalls, between

wingwalls and spandrel walls, and between structure sections and headwalls or

spandrel walls shall also be covered with a joint membrane.

The joint membrane shall be maintained in its installed location centered on the

joint. It shall not be damaged during the backfilling operation.

723.14

804

723.15Backfilling

Structure backfill shall be placed and compacted in accordance with 211.

Structure backfill shall be placed and compacted on each side of the structure to the450

fill line shown on the plans. During the backfill operation, the difference in elevations

of the fill on each side of the structure shall not exceed 24 in.

Unless otherwise specified by the manufacturer on the working drawings, once

the level of structure backfill reaches the top of the structure, two lifts shall be placed

and hand compacted over the structure without traversing the structure with heavy

equipment. Compaction with heavy equipment will not be allowed until a minimum

of two lifts have been placed, hand compacted, and accepted.

The operation of equipment over the structure shall be in accordance with the460

structure manufacturer’s recommendations.

723.16Scour Protection

When riprap is specified, geotextile shall first be placed on the in-situ soil in

accordance with 616.11. Riprap shall then be placed in accordance with 616.

For concrete base slabs, concrete shall be placed in accordance with 702.

723.17Method of Measurement

Precast reinforced concrete three-sided flat-topped structures or structure470

extensions, precast reinforced concrete three-sided arch-topped structures or structure

extensions, precast reinforced concrete true arch structures or structure extensions,

cast-in-place reinforced concrete three-sided flat-topped structures or structure

extensions, cast-in-place reinforced concrete three-sided arch-topped structures or

structure extensions, and cast-in-place reinforced concrete true arch structures or

structure extensions will not be measured. The accepted quantities for payment will

be the quantities shown on the plans.

Structure backfill will be measured in accordance with 211.09. Flowable backfill

will be measured in accordance with 213.08. Geotextile and riprap will be measured480

in accordance with 616.12. Field drilled holes will be measured in accordance with

702.27

Plain or coated reinforcement or WWR used in precast reinforced concrete three-

sided flat-topped structures or structure extensions, precast reinforced concrete three-

sided arch-topped structures or structure extensions, precast reinforced concrete true

arch structures or structure extensions, precast headwalls, precast wingwalls, cast-in-

place reinforced concrete three-sided flat-topped structures or structure extensions,

cast-in-place reinforced concrete three-sided arch-topped structures or structure

extensions, cast-in-place reinforced concrete true arch structures or structure490

extensions, cast-in-place headwalls, or cast-in-place wingwalls will not be measured

for payment.

723.15

805

If the Contractor elects to provide a box structure in lieu of the three-sided

structure shown on the plans, it will be measured in accordance with 714.11.

723.18Basis of Payment

The accepted quantities of precast reinforced concrete three-sided flat-topped

structures or structure extensions, precast reinforced concrete three-sided arch-topped

structures or structure extensions, precast reinforced concrete true arch structures or500

structure extensions, cast-in-place reinforced concrete three-sided flat-topped

structures or structure extensions, cast-in-place reinforced concrete three-sided arch-

topped structures or structure extensions, and cast-in-place reinforced concrete true

arch structures or structure extensions, of the size specified will be paid for at the

contract unit price per linear foot.

Structure backfill will be paid for in accordance with 211.10. Flowable backfill

will be paid for in accordance with 213.09. Geotextile and riprap will be paid for in

accordance with 616.13. Field drilled holes will be paid for in accordance with 702.28.

510

If the Contractor elects to provide a box structure in lieu of the three-sided

structure shown on the plans, it will be paid for in accordance with 714.12. The

Department will not incur additional cost for allowing the Contractor to substitute a

box structure for the three-sided structure shown on the plans.

Payment will be made under:

Pay Item Pay Unit Symbol

Structure Extension, Coated Reinforced Concrete,520

Three-Sided Sections, ____ in. x ____ in. .......................... LFT

span rise

Structure Extension, Reinforced Concrete,

Three-Sided Sections, ____ in. x ____ in. .......................... LFT

span rise

Structure, Coated Reinforced Concrete,

Three-Sided Sections, ____ in. x ____ in. .......................... LFT

span rise

Structure, Reinforced Concrete,

Three-Sided Sections, ____ in. x ____ in. .......................... LFT530

span rise

The cost of all design, coring, testing, pedestals or extended legs, excavation,

repairs, plugging core and handling holes, mortar, grout, sealer, preformed flexible

joint sealant, joint membrane, cylinder molds, and necessary incidentals shall be

included in the cost of the structure or structure extension.

The cost of spandrel walls, concrete base slab, footings, and aggregate base under

footings shall be included in the cost of the structure or structure extension.

540

723.18

806

The cost of precast concrete headwalls, precast concrete wingwalls, cast-in-place

headwalls, or cast-in-place wingwalls shall be included in the cost of the structure or

structure extension.

The cost of plain or coated reinforcement or WWR used in precast reinforced

concrete three-sided structures, precast reinforced concrete three-sided structure

extensions, precast headwalls, precast wingwalls, cast-in-place reinforced concrete

three-sided structures, cast-in-place reinforced concrete three-sided structure

extensions, cast-in-place headwalls, or cast-in-place wingwalls shall be included in the

cost of the structure or structure extension.550

The cost of concrete used in a cast-in-place splice shall be included in the cost of

the structure extension.

The cost of footings for wingwalls and aggregate base under the wingwall

footings shall be included in the cost of the structure or structure extension.

The quantities for payment shall remain as shown on the plans whether the

Contractor installs the three-sided arch-topped structure or structure extension, the

three-sided flat-topped structure or structure extension, or the true arch shape structure560

or structure extension.

No additional payment will be made for carrying an underground drain through a

structure or structure extension. However, no deduction will be made for the volume

of concrete occupied by the drain pipe in a cast-in-place structure or structure

extension.

No additional payment will be made for the repair or replacement of existing

concrete damaged by Contractor operations.