508EQUIPMENT

508.01Mixing, Transportation, and Placement of PCC Mixtures

The Contractor shall provide and calibra te all equipment necessary for mixing, transportation, and placement of the PCCP.

508.02Mixing Plant

The concrete production equipment sha ll be capable of producing a uniform 10 mixture. A plant inspection in accordance with 106.03 will be made by the Engineer annually, after a plant is moved, or as deemed necessary.

Batching plants shall be equipped to proportion aggregates and bulk cement by weight by means of automatic and interlocked proportioning devices. PCCP produced 508.01

in accordance with 501 and 502 shall document each ingredient in each batch.

All scales shall be accurate to within ±0.5% throughout their range. For applied loads less than 1,000 lb on the cement scale and 4,000 lb on the aggregate scale, the 20 scales shall be accurate to 2.0% or 1 gradation.

Meters for both admixtures and water shall be accurate to within 1.0%.

Means of control shall be provided so that as the quantity desired in the weighing hopper is approached, the materials may be added at a slower rate and shut off with precision. The following proportioning tolerances shall be used for batching:

The plant shall be equipped with a recording device capable of producing a ticket to permanently record the batch number, time of day, weight of all materials in the mix, volume or weight of mixing water added, and admixture quantities or equipped with a suitable non-resettable batch counter which will correctly indicate the number of batches produced. The CMD number shall be included on the ticket.

The plant shall have separate storage bins or tanks for each material in the mixture. Each compartment shall discha rge efficiently and freely into the weighing hopper or feed through a meter.

The aggregate storage area shall be well drained. All stockpiles shall be sufficiently separated and identified by signs or other approved methods.

The storage bins shall be sealed and vented to preclude dusting during operation 50 and have a sampling port.

Separate tanks for each admixture shall be provided.

Weighing hoppers shall be constructed to eliminate accumulation of materials and to discharge fully. The fine aggregate and coarse aggregate shall be weighed separately into a weigh hopper in the respective amounts defined in the CMD. Separate scales and hoppers shall be used for weighing the cement. SCMs may be weighed into the 60 cement hopper in one cumulative operation provided that the portland cement is weighed in first. 508.02

The concrete mixing system shall be either a central stationary mixer or a transit truck mixer. Each mixer shal l have attached in a prominent place a manufacturer’s plate showing the capacity of the drum in terms of volume of mixed concrete, the speed of rotation of the mixing drum or blades, and the manufacturer’s name and address.

The mixer shall be capable of combining the ingredients of the concrete within the specified time into a thoroughly mixed and uniform mass.

Stationary mixers shall be equipped w ith a 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 at mixing speed may be verified. 80

508.03Transportation

Truck mixers and agitators shall be ca pable of maintaining and discharging the concrete at a satisfactory rate and degree of uniformity. The haul units shall be examined daily for accumulations of hardened concrete or mortar and compared to the manufacturer’s standard for wear of blades.

Bodies of non-agitating hauling equipment shall be smooth, mortar-tight, metal containers. They shall be capable of discharging the concrete at a controlled rate. The bodies shall be examined daily for accumulations of hardened concrete, mortar, or foreign matter.

508.04Placement Equipment

The paver shall spread, consolidate, and shape the freshly placed concrete in one complete pass to provide a dense and hom ogeneous pavement. The paver shall be of 100 sufficient weight and power to construct the specified PCCP, at an adequate variable forward speed, and without transverse, longitudinal, or vertical instability. The paver shall be equipped with an automated steering and elevation control system.

The paver shall consolidate by vibrating the concrete for the full width and depth of the PCCP. Vibration shall be accomplished by internal vibrators, which have a variable frequency range of 7,000 to 12,000 vibrations per minute. The amplitude of vibration shall be between 0.025 in. and 0.06 in. The vibrators shall be spaced and 508.03

operated to achieve acceptable consolidation. The paver shall include a handheld tachometer or other suitable device for measuring the frequency of the vibrators. The 110 automated vibrator control shall be capable of stopping vibration when forward movement ceases.

Mechanical tie bar inserters shall be ri gidly attached to the paver and may be operated manually or automatically controlled.

A mechanical belt placer, if used, sha ll have a re-combini ng deflector plate mounted on the end of the discharge belt.

The finishing machine shall be supported by forms and be equipped with two or more oscillating type transverse screeds and a transverse smoothing float.

Forms for riding equipment shall be of sufficient thickness to maintain the true cross-section and shall be furnished in sections no less than 10 ft in length. Forms shall have a minimum depth equal to the prescribed edge thickness of the concrete pavement without a horizontal joint, and a minimum base width equal to the depth of the forms. Flexible or curved forms shall be of an acceptable design.

Forms shall be provided with adequate devices for secure setting so that when in 130 place they can withstand, without visible spring or settlement, the impact and vibration of the consolidating and finishing equipment. Flange braces shall extend outward on the base a minimum of 2/3 of the height of the form. The top face of the form shall not vary from a true plane by more than 1/8 in. in 10 ft and the upstanding leg shall not vary by more than 1/4 in. The forms shall contain provisions for locking the ends of abutting form sections together tightly for secure setting.

The transverse screed and transverse smoothing float shall be suspended from and guided by a rigid frame. The frame shall have a maximum effective wheel base of 14 ft. The length of the float shall be approximately 2 in. less than the normal width of 140 the pavement and have an adjustable crown section. The forward speed of the float shall be adjustable.

The vibration equipment shall consolidate the full width and depth of the strip of PCCP being placed. Vibrators may be either the surface pan type or the internal type with either immerse tube or multiple spuds.

Vibrators may be attached to the spreader or the finishing machine or mounted on a separate carriage. The frequency of the surface pan type shall be 3,500 impulses per minute or greater. The frequency of the internal type shall have no less than 5,000 150 impulses per minute for tube vibrators and spud vibrators shall have a frequency of from 10,000 to 12,000 impulses per minute in air.

The paver shall include a device, such as a handheld tachometer for measuring 508.04

the frequency of the vibrators. Vibrators shall have automatic controls, which stop vibration when forward motion ceases. The maximum spacing of spud vibrators shall be 2 ft. A warning device shall be connected to each vibrator circuit to indicate a failure of any individual vibrator and shall be visible from the ground.

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Steel forms shall be 10 ft or greater in length. Forms shall be capable of being staked in three locations or more for each 10 ft section and shall be equipped to interlock. Forms shall support finishing equipment without deflection in either the vertical or horizontal direction. The top face of the form shall not vary from a true plane by more than 1/8 in. in 10 ft.

Wood forms shall support finish equipment without deflection in either vertical 170 or horizontal direction.

Finishing equipment shall be capable of producing a uniform surface free of voids and in accordance with the planned profiles and cross-section.

A mechanical tube finisher shall consist of a single or multiple rotating strike-off/finish tubes setting approximately transverse to the longitudinal movement of the machine. The length of finish tubes shall be a minimum of 2 ft longer than the planned PCCP width. The forward speed of the machine as well as the rate of the finish 180 tube rotation shall be variable and it shall be reversible to allow for multiple finish passes.

A vibratory screed finisher shall consist of a truss frame with a minimum base width of 1 ft, which extends across the transverse width of the PCCP. The frame shall extend 2 ft beyond the width of the PCCP and shall hold its shape when moved forward. The screed shall move forward with either hydraulic or manual winches capable of maintaining the screed at a right angle to the direction of travel. The screed shall be vibrated as it moves forward and the vibration shall stop when forward motion ceases. Vibration shall be accomplished with mechanical driven eccentric weights or 190 with auxiliary driven pneumatic vibrators.

A mechanical bridge deck finishing machine shall consist of a single or multiple rotating cylinders setting approximately para llel to the longitudinal movement of the machine and operating transversely. The forward motion of the machine as well as the transverse movement of the finish cylinders shall be variable.

A hand operated strike off shall be rigid and shall hold its shape when moved forward with a combined longitudinal and transverse motion.

508.04

A mechanical belt placer, if used, sha ll have a re-combini ng deflector plate mounted on the end of the discharge belt.

Hand spud vibrators shall be capable of transmitting 7,000 to 10,800 impulses per minute in air. The diameter of the head shall be 1 1/4 to 2 1/2 in.

508.05Curing

Mechanical equipment shall be self-supported and ride on wheels or tracks located outside the paving lane. The mechanical sprayer shall be capable of applying a 210 continuous uniform film at a minimum rate of 1 gal./150 sq ft and shall be of the fully atomizing type. The equipment shall provide adequate agitation of the compound during application.

Hand spraying equipment shall be of the fully atomizing type.

508.06Texturing Equipment

Mechanical texturing equipment shall be capable of forming transverse grooves of uniform depth and alignment in the plastic PCCP, without tearing the surface. The texturing comb shall have steel tines spaced as specified. 220

Hand tools consisting of fluted floats, rakes with spring steel tines, or finned floats with a single row of fins shall produce grooves which conform to the same requirements as those specified for the grooves formed by the mechanical equipment.

508.07Sawing Equipment

Sawing equipment shall be self-propelled single or gang-mounted units. The saw

shall be capable of maintaining the specified alignment and depth of cut without

damaging the PCCP.

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508.08Miscellaneous Equipment

Long handled floats used to smooth and fill in open texture areas in the pavement

shall have blades no less than 5 ft in length and 6 in. in width. Equipment made of or

coated with aluminum or aluminum alloys shall not be used.

Straightedges shall be 10 ft in length and mounted on a long handle. The handle

shall be 3 ft longer than 1/2 of the width of the pavement being placed.

240

Joint sealant material shall be installed using manufacturer’s recommended

equipment.

Air compressors shall be capable of producing a minimum air pressure of 80 psi.

508.08

470

Water blasting equipment shall be capable of operating at 1,500 psi without

damaging the PCCP.

Grinding shall be completed by mechanical grinding equipment using diamond

tipped saw blades mounted on a power driven, self-propelled machine containing

transverse and longitudinal grade controls. The cutting head shall be no less than 36 in.

wide to produce a uniform texture per the full width of the cutting head shaft.

The pavement surface after cutting shall have a uniform texture but shall not be

smooth or polished. Tearing or dislodging of aggregates will not be allowed.

508.09Testing Facility and Equipment

260

The testing facility shall be capable of maintaining a controlled curing

environment in accordance with AASHTO T 23 and contain sufficient storage tanks

with curing solution to cure both production control and acceptance test beams.

Water shall be conveniently available for cleaning testing equipment and for

serving other tasks at the facility. Office space, having suitable heat and air

conditioning, shall be provided to the Department within the testing facility. A

telephone shall be provided in the testing facility. Floor space shall be provided for a

Department furnished beam breaker.270

A current set of AASHTO’s Standard Specifications for Transportation Materials

and Methods of Sampling and Testing, Part 2 Tests, and ASTM C173 shall be

provided.

Testing equipment shall be provided to perform production control testing and

shall be maintained in suitable working order. The equipment shall be in accordance

with AASHTO requirements where applicable. The Contractor shall provide a spud

vibrator with power source in suitable working order.280

The inertial profiler shall be in accordance with ITM 917.