Portland Cement Concrete Equipment Art. 1103.01 of order, the Contractor will be permitted to operate while it is being repaired, provided the Contractor furnishes an approved timepiece equipped with minutes and seconds, and provided that each batch is mixed 1 1/2 minutes. If the timing device is not repaired within 72 hours, further use of the mixer will be prohibited until repairs are made. When measuring water by volume, the mixer shall be equipped with a water measuring device which shall be capable of measuring and discharging the specified amount of water within a limit of accuracy of one percent, except a limit of accuracy closer than 1 qt (1 L) will not be required, and shall be so arranged that the accuracy of measurement will not be affected by variations in pressure in the water supply line. A water glass placed vertically on the water tank shall not be used as a water measuring device. The water measuring equipment shall include an auxiliary tank of approved design from which the water measuring tank shall be filled. The volume of the auxiliary tank shall be not less than the volume of the measuring tank. The equipment shall be so arranged that the water pressure in the measuring tank cannot exceed that due to the difference in elevation between the two tanks. The measuring tank shall be equipped with an outside tap and valve to provide for checking the graduation on the indicator, unless other means are provided for readily and accurately determining the amount of water discharged. Means shall be provided to automatically stop the flow of water from the measuring tank when the desired quantity has been delivered. If the specified amount of water can be provided without the auxiliary tank, the auxiliary tank will not be required. When measuring water by weight (mass), the requirement for the scale shall be as specified in Article 1103.02(c), the accuracy of measuring shall be as specified above, and means shall be provided for automatically stopping the flow of water into the weighing container at the moment the correct amount has been delivered. A water meter may be used for measuring water provided it meets the requirements for automatic stop of the flow of water and accuracy of measurement. Pickup and throw-over blades in the drum of the mixer which are worn down 3/4 in. (19 mm) or more in depth shall be replaced with new blades.
b.Truck Mixer. Truck mixers shall be either the type having a watertight revolving drum, suitably mounted and fitted with adequate blades attached to the drum, or the type having an open-top, watertight, trough-like container, suitably mounted and fitted with adequate blades revolving about an axis parallel to the axis of the trough. Truck mixers shall be capable of combining materials into a uniform mixture, and of discharging the mixture without segregation. Truck mixer blades at the point of maximum drum diameter, nearest to the drum head, shall not be worn more than ten percent of the original radial height. The radial height shall be determined according to the National Ready Mixed Concrete Association’s Certification of Ready Mixed Concrete Production Facilities/Plant Certification Check List document, the blade dimensions provided by the manufacturer, or other available information. Art. 1103.01 Portland Cement Concrete Equipment Truck mixers, except when used exclusively for agitating premixed concrete, shall be provided with a batch meter and locking device capable of preventing the discharge of the concrete before the required number of revolutions has been obtained, or with an approved revolution counter, suitably mounted, to provide a means of verifying the amount of mixing obtained. The water measuring device shall be capable of measuring and discharging the specified amount of water within a limit of accuracy of one percent, except a limit of accuracy closer than 1 qt (1 L) will not be required. If the water is added during transit, the measuring device may be mounted upon the truck mixer, and an outside tap or valve shall be provided for checking the graduations on the indicator, unless other means are provided for readily and accurately determining the amount of mixing water discharged. Provisions shall be made to automatically stop the flow of water when the desired amount has been delivered. If not mounted on the truck mixer, the water measuring device shall be located at the site selected for adding the water, and shall be according to the requirements of Article 1103.01(a). A water glass placed vertically on the water tank shall not be used as a water measuring device, except for final slump adjustment at the job site. The equipment for weighing and batching the materials for truck mixing shall be according to Article 1103.02. The truck mixer shall be approved before use according to the Bureau of Materials Policy Memorandum, “Approval of Concrete Plants and Delivery Trucks”.
c.Truck Agitator. Truck agitators shall be either the type having a watertight revolving drum, suitably mounted and fitted with adequate blades attached to the drum, or the type having an open-top, watertight, trough-like container, suitably mounted and fitted with adequate blades revolving about an axis parallel to the axis of the trough. The truck agitator, when fully loaded, shall be capable of maintaining the mixed concrete in a thoroughly mixed and uniform mass, and of discharging the concrete without segregation. For the open-top truck agitator, a watertight cover shall be used to protect the concrete when it is raining. The truck agitator shall be approved before use according to the Bureau of Materials Policy Memorandum, “Approval of Concrete Plants and Delivery Trucks”.
d.Nonagitator Trucks. Nonagitator trucks shall have a metal container that is smooth, watertight, and non-reactive to concrete. Nonagitator trucks shall be capable of discharging the concrete at a satisfactorily controlled rate and without segregation. A watertight cover shall be used to protect the concrete when it is raining. The nonagitator truck shall be approved before use according to the Bureau of Materials Policy Memorandum, “Approval of Concrete Plants and Delivery Trucks”. Portland Cement Concrete Equipment Art. 1103.02
1103.02 Batching and Weighing Equipment. The plant shall be approved
before production begins according to the Bureau of Materials Policy Memorandum, “Approval of Concrete Plants and Delivery Trucks”. The bins, weighing hoppers and scales shall be arranged to the satisfaction of the Engineer so that the weigh beam "telltale" dial, or the dial scale, or the digital readout is in full view of the operator controlling the gates, valves or belts that feed the material into the weighing hopper. The equipment used for batching and weighing the materials shall comply with the following requirements.
a.Bins and Silos. Bins and silos shall have sufficient capacity for adequate supply of materials to the weighing hoppers. They shall be supported by rigid frame work on a safe foundation. Portable type bins and silos shall be fully loaded and permitted to stand for at least 12 hours before operations start. Bins and silos shall have separate compartments for each aggregate, cement, and finely divided mineral used. Except for permanently located plants, the top of the fine aggregate compartment shall be equipped with a tilted screening device which shall reject all material coarser than 1 in. (25 mm) and through which all fine aggregate must pass upon entering that compartment. Each compartment shall be designed to discharge material efficiently and freely into the measuring hopper. Means of control shall be provided so that when the quantity to be obtained is being approached, the flow of the material can be gradually retarded and completely shut off, without leakage, at the moment the desired amount has been discharged.
b.Weighing Hoppers. The hoppers shall be completely suspended from the scales and shall otherwise hang free and, except as further provided, shall have sufficient capacity to contain the material or materials to be weighed for one batch without shoveling and without jiggling the hopper to keep bin gates and chute openings free of material during the weighing. Cement shall be weighed in a hopper entirely free and independent of the hopper or hoppers used for weighing the aggregate. When manually batching, finely divided minerals shall be weighed in a separate hopper. Finely divided minerals may be weighed into the cement weigh hopper for automatic or semi-automatic batching. Batching equipment, insufficient in capacity to weigh the materials required for a full batch, will be permitted for stationary mixers and truck mixers provided that the capacity of the hopper or hoppers is sufficient to weigh all the materials for at least 1 cu yd (0.75 cu m) of concrete for any mixer of rated capacity of 1 cu yd (0.75 cu m) or larger. The batching equipment shall be limited to a maximum of three weighings of each material for charging the mixer. All hoppers, except cement, shall have a port or other opening for removal of overload of any one of the materials unless sufficient clearance for this purpose exists between the bottom of the bin gate and the top of the hopper. The top of the cement hopper shall be closed to prevent the escape of cement while it is being weighed. Hoppers shall be constructed in a manner that will eliminate the accumulation of tare material and leakage through the discharge gates during weighing. They shall be capable of discharging the Art. 1103.02 Portland Cement Concrete Equipment material efficiently and completely into the batch trucks or mixer without the necessity of beating or jiggling. If any hopper, in the opinion of the Engineer, does not discharge the material satisfactorily, it shall be provided with a vibrator of sufficient frequency and power to ensure complete discharge. For cement and finely divided minerals, a device shall indicate the complete discharge of materials. All weighing hoppers shall be enclosed or otherwise protected against wind.
c.Scales. The scales may be of either the horizontal beam or the springless dial type, shall be designed as an integral unit of the batching equipment, and shall be constructed to withstand the usage for which they are intended. Load cells with digital readouts may also be used. Beam type scales shall have as many beams and of such capacities as will permit the required weight (mass) of each aggregate to be set off on a single beam, except that when one aggregate is required, two weigh beams will be permitted. The scale shall be provided with suitable lockouts so that the weigh beams may be engaged to weigh in the desired order. Each weigh beam shall have some means or device to indicate when the beam is in the proper balance position. Poises shall be constructed so that they will be held firmly in position. Beam scales shall have provisions such as a "telltale" dial for indicating to the operator that the required load in the hopper is being approached. Such device shall indicate at least the last 200 lb (90 kg) of load in the case of scales used for weighing aggregate, and at least the last 100 lb (45 kg) of load in the case of scales used for weighing cement and finely divided minerals, and shall be placed in a position from which it can be viewed without parallax by the operator while charging the hopper. Except for permanently located plants, springless dial scales shall be provided with suitable markers inside the glass cover and in front of the dial which may be set to show the position of the dial indicator for the required load or the various accumulative loads when more than one aggregate is weighed in the same hopper. Markers shall have distinctive colors for the various materials to be weighed. Dials shall be placed so that they can be viewed without parallax by the operator. The value of the minimum graduation interval of any scale used for weighing materials shall be not more than 0.2 percent of the batch weight (mass) and not more than 0.1 percent of the capacity of the scale, except that graduation intervals less than 5 lb (2 kg) when weighing aggregates and less than 2 lb (1 kg) when weighing cement and finely divided minerals will not be required. In the case of beam scales, the same requirement shall also apply to the graduation of each individual beam with respect to the weight (mass) of material normally weighed on it. The value of the minimum graduation interval of any scale used for weighing mixing water shall be not less than 2 lb (1 kg). All scales shall be designed and built to a maximum tolerance of 0.4 percent of the net load in the hopper. Cement shall be weighed on a scale separate and distinct from the scale or scales used for weighing other materials. Mixing water, when weighed, shall be subject to the same requirement as cement. Finely divided minerals shall be weighed on a separate scale unless the batching equipment is automatic Portland Cement Concrete Equipment Art. 1103.03 or semi-automatic. When a beam scale is used for weighing cement, a tare beam shall be provided and the weigh beam or beams shall be capable of being lifted out of weighing position so that the tare weight (mass) of the hopper can be checked after each weighing operation to determine if all of the cement or finely divided minerals has been discharged into the batch. Scales shall be housed or otherwise protected against the effect of wind in a manner meeting the approval of the Engineer. The scales shall be calibrated by an independent company. The independent company shall have scale testing equipment and standard weights meeting the requirements of NIST. The scale calibration will be observed by the Engineer. Scales shall be calibrated at the beginning of each construction season or each 12 month period, and each time the scales are moved, or when scale components are repaired or replaced. Once a scale is calibrated, the settings shall not be altered. The concrete producer shall submit for approval by the Engineer, a method to verify the settings have not been altered. If at any time the Engineer determines the settings have been altered, a new calibration will be required. Means of access for inspection purposes shall be safe and shall meet the approval of the Engineer. In the case of permanently located plants, the means of access shall be an inclined stairway with the handrail located so that its upward flight will end on the scale operator's platform. It shall be firmly attached to the supporting members of the bin. The weigh platform shall have an approved floor of metal grid or 2 in. (50 mm) plank.
d.Slurry Mixer. A slurry mixer may be used to premix cement, finely divided minerals, water, and admixtures before discharge into a stationary mixer or truck mixer. The equipment shall be a vortex type, paddle type, or other type approved by the Engineer. The vortex type shall have an impeller for mixing. The paddle type shall have mixing blades and paddles for mixing. The batching equipment shall have a moisture sensor to measure the fine aggregate moisture, when the slurry mixer is operated. The cement, finely divided minerals, and water shall be measured in the slurry mixer, according to Article 1020.10. The mixing of materials in the slurry mixer shall result in a uniform mix, which shall flow into the stationary mixer or truck mixer. The batching equipment shall have the ability to batch cement and finely divided minerals with or without the use of the slurry mixer.
1103.03 Automatic and Semi-Automatic Batching Equipment. Automatic
equipment for weighing, measuring, batching and mixing materials shall be according to Articles 1103.01 and 1103.02, except as follows.
a.General Requirements. It is the purpose of the requirements set forth herein that automatic and semi-automatic batching equipment shall render impossible the omission of any one of the required materials from any batch, and that duplications of measurement of any one material into any batch shall not occur. Further, it is the intent that the amounts of materials Art. 1103.03 Portland Cement Concrete Equipment entering into any batch shall be accurately measured within the specific tolerances set forth herein. In the case of stationary mixers, it is intended that each batch shall be mixed during the full period required after all the materials have entered the mixer, and that recharging the mixer shall not occur before the previous batch has been discharged. Certain requirements to further the objects stated are as follows.
1.Allowable Tolerances. Aggregates measured individually or cumulatively, shall have a tolerance within ±1 1/2 percent of the required quantity. Cement and cementitious materials measured individually or cumulatively, shall have a tolerance within ±1 percent of the required quantity. Water shall be measured to a tolerance within ±1 percent of the required quantity. Admixtures shall be measured to a tolerance within ±3 percent of the required quantity. The interlock control shall be set to the required tolerance.
2.Weighing Control. Arrangement shall be such that any scale of the system can be conveniently checked for accuracy at any time that this should be considered desirable. All scales shall be designed and built so that, when any drag due to weighing control devices is included, an accuracy within the maximum tolerance of 0.4 percent of the net load in the hopper will be maintained.
3.Water Measuring Control. When the mixing water is measured volumetrically, provisions shall be made for bypassing the measured water into a container for checking the accuracy of delivery. If the water is measured during the course of its flow into the batch, means shall be provided to show, at any time during the flow, the amount that has entered. Devices for volumetric measurement of mixing water, in the case of automatic systems, shall automatically reset at the initial position immediately after delivery of the measured amount, ready for the next succeeding batch cycle.
4.Admixture Control. The dispenser for an admixture shall meet the requirements for automatic or semi-automatic batching. Liquid admixtures shall be protected from freezing and contamination. Agitation shall be provided for liquid admixtures which are not stable solutions. To provide a visual indication the liquid admixture is actually entering the batch, the tube conducting the admixture into the stream of mixing water or directly on the aggregate shall be transparent or translucent, or shall have a transparent or translucent section. If approved by the Engineer, an alternate indicator may be used for high range water- reducing admixtures and corrosion inhibitor admixtures. The dispenser’s visual indicator shall be easily viewed by the plant operator when batching. Televised images may be used.
5.Control of Mixing Time. When automatic or semi-automatic batching equipment, in connection with stationary mixers, are used for successive batches of the same size, the mixing time adjusting control Portland Cement Concrete Equipment Art. 1103.03 shall be capable of being locked with a key. As an alternative to a locking key, the start and finish time for mixing may be automatically printed on the batch ticket. The start and finish time shall be reported to the nearest second.
b.Automatic Batching Equipment. Automatic batching equipment shall be provided with gates, valves, or other suitable devices, which, when activated by a single starting mechanism, shall set in motion the charging of weigh hoppers or other containers, and which, in weighing or measuring any given material, shall automatically stop the flow of that material when the desired amount, within the allowable tolerance, has been attained. Automatic batching equipment shall be capable of having quantities preset on a central control panel that will result in correct measurement of each material for each batch, and control adjustments shall be capable of being performed on that panel. For any material measured by weight (mass), a suitable "over" and "under" indicating device shall be provided, showing whether the amount of material weighed is within the allowable tolerance. Interlock shall be provided (1) so that the charging device can open or start only when the scale indicates zero load and when the weigh hopper or container discharging gate or valve is closed, and (2) so that the discharging gate or valve can open only when the desired weight (mass) within the allowable tolerance is in the weigh hopper or container and when the charging device is closed or stopped. If more than one aggregate is weighed cumulatively into the same hopper, control and interlock shall be provided with respect to each increment of weighing, as required for a material weighed into an individual hopper. It shall not be mandatory that the mixing water and air-entraining admixture be measured by weighing. These materials may be measured volumetrically, if the specified controls, or other equally effective means are provided, and if the measurements are within the specified tolerance. Automatic batching equipment for weighing or measuring batch quantities in increments shall be provided with an automatic repeater having a counter that can be set for the number of increments required, and which shall ensure that the required number of increments are accurately delivered and discharged into each batch. An automatic batching system shall consist of the combination of automatic batchers necessary for batching the materials required. All shall be activated by a single starting mechanism and the system shall be completely interlocked. In the case of stationary mixers, interlock shall be provided so that the discharging gates or valves can open only when the mixer is in the proper position for receiving the materials. The interlock of the system, with respect to sequence of discharge of the materials into the mixer, shall be such that the mixing water and air-entraining admixture are discharged according to the requirements of Articles 1020.08 and 1020.11. Means shall be provided for convenient adjustment, from preset quantities, of the amounts of the aggregates, the mixing water and the air-entraining admixture, as based on tests of the aggregates and observations and tests of the mixture being produced. Suitable equipment indicating the amount of Art. 1103.03 Portland Cement Concrete Equipment free water in the fine aggregate, as it is being batched, shall be provided, and the quantities of fine aggregate and mixing water shall be adjusted currently, as concrete is being produced, so that the desired amounts of these materials enter into each batch. Other adjustments of the quantities, as preset for automatic control, shall be made only at the direction of the Engineer. The operator shall not interfere with the operation of any part of the scale mechanism during the weighing process for the purpose of circumventing the interlock or malfunction of the equipment. Failure to comply with this requirement shall be cause for the Engineer to require that the equipment be provided with a positive means for preventing such interference. A batching system consisting of a combination of semi-automatic batchers, as described below, and automatic batchers may be approved, provided that control and interlock shall be as prescribed for automatic batchers.
c.Semi-automatic Batching Equipment. Batching equipment which does not substantially comply with all the requirements prescribed for automatic batching equipment, but which meets at least the following described minimum conditions, will be considered as semi-automatic batching equipment. As a minimum requirement, semi-automatic batching equipment shall be provided with gates, valves or other suitable devices, which open or start separately, when actuated by individual starting mechanisms, to permit the material to be weighed or measured, and close or stop automatically when the desired amount, within the allowable tolerance, has been attained. Interlock with respect to individual units and "over" and "under" indicating devices shall be provided as prescribed for automatic batching equipment. Other features prescribed for automatic batching equipment may be incorporated and approved. A semi-automatic batching system shall consist of the combination of semi- automatic batchers necessary for batching the materials required. The system may be partially or completely interlocked. For semi-automatic batching systems constructed so that materials are batched at more than one stop or location, a separate control panel shall be furnished at each location, unless the operations can be controlled from a central location in a manner that will ensure that the correct amount of material is included in each batch. In the event that movement of trucks receiving the batches is necessary during the operations at any location, a separate control panel shall be provided at that location, and an operator shall be present to ensure that the batches are discharged correctly into their respective compartments. However, if effective interlock is provided between the movement of trucks and the batching mechanism so that batches can be discharged only as required without omission or duplication, and as each batch compartment is brought into correct position, then the operations may be conducted from a centrally located control panel. Portland Cement Concrete Equipment Art. 1103.04 The operator shall not interfere with the operation of any part of the scale mechanism during the weighing process for the purpose of circumventing the interlock or malfunction of the equipment. Failure to comply with this requirement shall be cause for the Engineer to require that the equipment be provided with a positive means for preventing such interference. A batching system consisting of a combination of semi-automatic and manual batchers may be approved, provided that satisfactory control of the batching is attained.
d.Manual Operation. Automatic and semi-automatic batching equipment may be constructed so that they can be switched to manual control. When switching to manual control is necessary, the batching operations shall continue only until repairs can be made, but not for a period exceeding 72 hours, unless otherwise approved by the Engineer. If provision is made for switching to manual operation, then the scale, or a scale follower approved by the Engineer, shall be placed within easy view of the operator, but not farther than 20 ft (6 m) from the location from which the manual batching is being performed. Dial scales shall be placed so that they can be viewed without parallax.
1103.04 Mobile Portland Cement Concrete Plants. The mobile concrete
plant shall meet the following minimum requirements.
a.The mixer shall be capable of carrying sufficient unmixed materials to produce not less than 6 cu yd (4.6 cu m) of concrete.
b.The mixer shall be capable of positive measurement of cement being introduced into the mix. A recording meter visible at all times and equipped with a ticket printout shall indicate this quantity.
c.The mixer shall provide positive control of the flow of water into the mixing chamber. Water flow shall be readily adjustable for variations in aggregate moisture.
d.The mixer shall be capable of being calibrated to automatically proportion and blend all components on a continuous or intermittent basis, as required by the finishing operation, and shall discharge mixed material through a conventional chute.
e.The mixer shall be calibrated annually by a commercial testing laboratory. Copies of calibration charts shall be maintained in the truck and also the District office.
f.The mixer shall be maintained clean and in good repair.
g.The mixer shall meet all requirements of AASHTO M 241. Art. 1103.05 Portland Cement Concrete Equipment
1103.05 Forms. Forms shall be as follows.
a.Pavement (Subbase, Base Course, and Surface Course) and Shoulder. Flexible or curved forms of proper radius, made of either metal or wood, shall be supplied for use on curves of 100 ft (30 m) radius or less. At all other locations, unless approved by the Engineer, side forms for pavement shall be metal. They shall be of an approved cross section, and shall be furnished in sections not less than 10 ft (3 m) in length. They shall have a height not less than the edge thickness of the pavement to be constructed, a base width equal to or greater than the height and shall be made of metal not less than 1/4 in. (6 mm) in thickness, except that a minimum thickness of 3/16 in. (5 mm) will be permitted if the form is of trapezoidal cross section. They shall have flange braces extending outward on the base not less than 2/3 the height of the form and spaced not more than 5 ft (1.5 m) apart. Each section shall have a steel pin at each end and at least one intermediate pin, and provision shall be made to lock all pins to a true grade. Locked joints shall be provided between form sections to maintain the alignment and elevation of the form line. Metal forms shall withstand loading imparted by the paving train without distortion or settlement of the form line. They shall be straight and free from warp. Any form varying on its upper edge more than 1/16 in. in 10 ft (2 mm in 3 m) from a straight line will be rejected. The longitudinal axis of the upstanding leg shall not vary more than 1/4 in. in 10 ft (6 mm in 3 m) from a straight line. The use of wood forms will not be permitted unless approved by the Engineer. When used, wood forms shall be a minimum of 2 in. (50 mm) thick (nominal dimension) surface plank, with the exception of curved or flexible sections, and shall be the full depth of the concrete slab; shall be straight and free from warp; shall provide for rigid, smooth connections; and shall provide ways and means to be securely fastened in place to the lines and grades given. Metal forms that will be used to support a screed shall be made of no less than 10 gauge (3.4 mm) steel with a minimum 4 in. (100 mm) wide base and have a minimum of two flange braces with provisions for pin locking in each 10 ft (3 m) section. Metal pins shall be of proper size and length to hold the forms rigidly and securely in place. Metal forms may be built-up with a single layer of wood plank, 2 in. (50 mm) thick or less when the specified pavement thickness differs from standard manufactured form sizes. The wood plank shall be well seasoned surfaced hardwood free from warp and twist. The plank shall be attached to the bottom of the metal form with two lines of bolts at not more than 2 ft (600 mm) centers on each line. The width of the plank shall equal or exceed the pavement thickness.
b.Concrete Gutter, Curb, Median and Paved Ditch. The forms shall be of wood or metal, straight and free from warp, and of sufficient strength to Portland Cement Concrete Equipment Art. 1103.13 resist springing during the process of depositing the concrete against them. Wood forms shall be a minimum of 2 in. (50 mm) thick (nominal dimension) surface plank, except wood forms less than 2 in. (50 mm) thick may be used for short radii. Metal forms shall be of an approved section and shall have a flat surface on the top. Forms shall be so designed that divider plates or other devices for holding the form in place will not cause planes of weakness in the concrete and subsequent cracking. The forms shall be of a depth of the curbing, median or paved ditch, and so designed as to permit secure fastening together at the tops.
1103.06 Reserved.
1103.07 Reserved.
1103.08 Subgrade Planer. The subgrade planer shall be a motor grader
according to Article 1101.05 with a moldboard that can be adjusted to perform fine grading. The motor grader shall be of sufficient weight (mass) so as not to rise from the pressure of the material being planed. The motor grader shall produce a cross section in accordance with the plans and shall not develop a center deflection of more than 1/8 in. (3 mm).
1103.09 Subgrade Machine. The subgrade machine shall be self-propelled
and mounted on crawler type tracks. It shall be equipped with a rotating drum fitted with cutting teeth capable of cutting and trimming earth, aggregate and hot-mix asphalt, and so designed that they may be accurately adjusted vertically and held in place. The machine shall have a moldboard to provide the final surface and texture. It shall weigh not less than 7000 lb (3200 kg) and shall have such strength and rigidity that it will not develop a center deflection of more than 1/8 in. (3 mm). The subgrade machine shall be equipped with an automatic electronic grade control device. The device shall be capable of controlling the elevation of the subgrade machine relative to either a preset grade control stringline or a traveling grade reference. The method of grade control shall be approved by the Engineer.
1103.10 Reserved.
1103.11 Water Supply Equipment. The water supply equipment shall be of
such capacity and design as to ensure an ample supply and adequate pressure simultaneously for all of the requirements of machinery, mixing, curing, wetting subgrade, and all other features of the work.
1103.12 Reserved.
1103.13 Finishing Machine. Finishing machines shall be according to the
following.
a.Bridge Decks and Approach Slabs. The finishing machine shall be equipped with: (1) a mechanical strike off device; and (2) either a rotating cylinder(s) or a longitudinal oscillating screed which transversely finishes the surface of the concrete. The finishing machine shall produce a deck surface of uniform texture, free from porous areas, and with the required surface smoothness. Art. 1103.13 Portland Cement Concrete Equipment The finishing machine shall be operated on rails or other supports that will not deflect under the applied loads. The maximum length of rail segments supported on top of beams and within the pour shall be 10 ft (3 m). The supports shall be adjustable for elevation and shall be completely in place to allow the finishing machine to be used for the full length of the area to be finished. The supports shall be approved by the Engineer before placing of the concrete is started. A vibrating screed for finishing may also be used according to
Article 503 — 16(a).
b.Pavement (Subbase, Base Course, and Surface Course) and Shoulder. Finishing machines shall be according to the following.
1.The finishing machine shall be according to Article 1103.13(a) except it may travel on top of rails, forms, or other supports.
2.Screeds per Article 1103.17(g) may be used under the following conditions.
a.Restricted clearance outside the forms.
b.Mainline pavements with a posted speed of less than or equal to 40 mph.
c.Where a continuous line of forms more than 600 ft (180 m) cannot be set. Railroad tracks, bridges, existing paved intersections, or gaps shown in the plans such as at driveways and intersections or gaps ordered by the Engineer shall be considered as obstructions in the continuity of the form line.
d.Variable width pavement.
e.Pavement connector for bridge approach slabs when allowed per
Article 420 — 16.
1103.14 Concrete Finisher Float. The concrete finisher float shall be either
self-propelled or attached to a finishing machine. It shall be so designed to prevent tearing of the concrete surface or rolling of aggregate under the float. If self- propelled, it shall also be equipped with four or more wheels which ride on the forms and it shall be of sufficient weight (mass) as to resist flexing under the pressure of the concrete.
1103.15 Reserved.
1103.16 Formless Paver. The formless paver shall be self-propelled and
equipped with suitable devices for spreading, strike off, consolidation, and finishing of concrete the full-width and depth as shown on the plans without the use of fixed side forms. The tracks shall be of sufficient length and width to properly support the machine and its load without causing excessive depressions. The formless paver shall be equipped with strike off screed, and a sufficient quantity of internal vibrators spaced a maximum of 24 in. (600 mm) to consolidate the concrete mass throughout Portland Cement Concrete Equipment Art. 1103.17 its entire depth and width. The operating frequency of the internal type shall be 7,000 +/- 2,000 VPM. A vibrating reed tachometer, hand type, shall be provided with each paver. The vibrating reed tachometer shall have a range from at least 4,000 to 10,000 VPM. For a contract which has a minimum of 10,000 sq yd (8,350 sq m) of pavement that is at least 12 ft (3.6 m) wide, an electronic internal vibrator monitoring device shall be provided. The device shall be capable of displaying the operating frequency of each internal vibrator and shall be visible to the paving operator. The vibrator monitoring device shall have a range from at least 4,000 to 10,000 VPM. The formless paver shall be capable of constructing pavement to line and grade specified. The method of placing the concrete in front of the formless paver may be a separate operation at the Contractor’s option. The use of a material placer, mechanical spreader, or placer/spreader in front of the formless paver is acceptable. The formless paver shall be approved by the Engineer prior to starting the paving operations.
1103.17 Miscellaneous Equipment. Miscellaneous equipment shall be as
follows.
a.Hand Vibrator. The vibrator shall be the internal type. It shall be adequately powered to operate under full load at a frequency of 4500 VPM or greater; and shall have an intensity and period of vibration sufficient to obtain thorough consolidation of the concrete. The vibrator shall have a non-metallic head for areas containing epoxy coated reinforcement. The head shall be coated by the manufacturer. The hardness of the non-metallic head shall be less than the epoxy coated reinforcement, resulting in no damage to the epoxy coating. Slip-on covers will not be allowed.
b.Hand Tamper. Hand tampers, when required or permitted under these Specifications, shall meet the approval of the Engineer.
c.Header. The header shall be shaped to conform to the cross section required by the plans. It shall be wood or metal and of sufficient thickness and rigidity to provide a vertical construction joint. The header for continuous reinforced pavement shall be of wood or metal and shall be split longitudinally to provide for the proper depth of the continuous reinforcement steel according to the plans.
d.Foot Bridge. Foot bridges shall be durably constructed and readily movable. They shall be so designed that no part of the bridge will come in contact with the pavement at any time. Two or more foot bridges shall be provided.
e.Hand-Operated Longitudinal Float. The hand-operated longitudinal float shall be a minimum of 10 ft (3 m) in length and properly stiffened to prevent flexibility and warping during the finishing operation. The handle shall be a minimum of 3 ft (1 m) longer than 1/2 the width of the slab. Art. 1103.17 Portland Cement Concrete Equipment
f.Long-Handled Float. The long-handled float shall have a blade a minimum 3 ft (1 m) in length and 6 in. (150 mm) in width. The handle shall be of such length as will permit the operation of the float from the shoulder. Two or more such floats shall be provided.
g.Screed. For the following screed types, the screed shall be a minimum of 2 ft (600 mm) longer than the maximum width of the slab to be struck off, and consolidation of concrete with a hand vibrator shall be performed in front of the screed.
1.Vibrating Screed. A machine with a metal screed attached to a frame that uses a motor for vibration. When required, frame sections shall be capable of being set at an angle for crown or invert profiles.
2.Laser Screed. A machine with a plow, auger, and vibrator that has automatic laser control for placement of concrete to the correct elevation.
3.Roller Screed. A machine with one or more round tubes which rotate.
h.10 ft (3 m) Straightedge. The 10 ft (3 m) straightedge shall be made of suitable material, and shall be maintained in accurate alignment at all times. It shall be equipped with a handle at least 3 ft (1 m) longer than 1/2 the width of the slab. Two or more 10 ft (3 m) straightedges shall be provided.
i.Broom. Brooms shall be of push broom type, at least 18 in. (450 mm) in width. They shall contain a maximum of three rows of good quality bass or bassine fiber 4 1/2 in. (115 mm) or less in length. The handle shall be at least 1 ft (300 mm) longer than 1/2 the width of the slab and shall be readily adjustable. Two or more brooms shall be provided.
j.Edging Tool. The edging tools shall have a radius of 1/4 in. (6 mm), and shall be approved by the Engineer. Two or more edging tools shall be provided.
k.Fogging Equipment. Fogging equipment shall be hand held fogging equipment for humidity control. The equipment shall be capable of atomizing water to produce a fog blanket by the use of pressure 2500 psi (17.24 MPa) minimum and an industrial fire hose fogging nozzle or equivalent.
1103.18 Underwater Concrete Placement Equipment. Equipment for placing
concrete underwater shall be as follows.
a.Tremie. The tremie shall consist of a funnel shape hopper and a steel pipe with a minimum diameter of 10 in. (250 mm).
b.Concrete Pump and Lines. The concrete pump shall be equipped with lines having a minimum diameter of 4 in. (100 mm). The portion of the line inserted in the water shall be a steel pipe. Pavement Marking Equipment Art. 1105.01 Aluminum parts shall not be in contact with concrete. The steel pipe shall be clean, smooth, and shall have watertight connections. The steel pipe shall have sufficient thickness and weight to resist buoyancy when the pipe is not filled with concrete. The steel pipe shall be supported in a manner to allow for it to be raised or lowered rapidly. To start underwater concrete placement and prevent mixing of water and concrete, the discharge end of the steel pipe shall have a steel or wood flap gate with gaskets, or a wood plug which may float to the surface. The wood plug may be beveled to hold it in place, or it may be tied to the steel pipe to keep it in place. The wood plug shall be covered with a sheet of plastic or shall have a gasket. A traveling plug will not be permitted.
1103.19 Mechanical Side Tie Bar Inserter. The mechanical side tie bar
inserter shall be self-contained and supported on the formless paver with the ability to move independently from the formless paver. The insertion apparatus shall vibrate within a frequency of 2000 to 6000 vpm. A vibrating reed tachometer, hand type, shall be provided according to Article 1103.12.
1103.20 Mechanical Dowel Bar Inserter. The mechanical dowel bar inserter
(DBI) shall be self-contained and supported on the formless paver with the ability to move separately from the paver. The DBI shall be equipped with insertion forks along with any other devices necessary for finishing the concrete the full width of the pavement. The insertion forks shall have the ability to vibrate at a minimum frequency of 3,000 VPM. SECTION 1104. RESERVED SECTION 1105. PAVEMENT MARKING EQUIPMENT
1105.01 General. Pavement marking equipment shall include at least one
operator who shall be a technical expert in equipment operations and application techniques. All guns shall be in full view of the operator at all times.
a.Truck Mounted. Truck mounted equipment shall be capable of spraying both yellow and white markings according to the manufacturer’s recommended proportions and be mounted on a truck of sufficient size and stability with an adequate power source to produce lines of uniform dimensions and prevent application failure. The equipment shall have a metering device to register the accumulated installed quantities for each gun, each day. The application equipment shall be capable of automatically placing intermittent and continuous lines of the various widths and colors of pavement marking lines specified.
b.Hand Operated. Hand operated equipment shall meet the recommendations of the pavement marking material manufacturer. The Engineer may permit the use of a hand operated machine for those locations where only a limited quantity of lane and edge lining is required. Letters,
Referenced in this section
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Source: Illinois Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 1168–1182 of 1,217. View official source ↗