619POLYMER MODIFIED CONCRETE BRIDGE DECK OVERLAY FOR NEW AND EXISTING BRIDGES

619.01 Description ................................ ................................ ................... 650

619.02 Materials ................................ ................................ ...................... 650

619.03 Propor tioning ................................ ................................ ............... 651

619.04 Equipment ................................ ................................ .................... 651

619.05 Limitations ................................ ................................ ................... 654

619.06 Hydro -Demolition ................................ ................................ ........ 655

619.07 Cleaning ................................ ................................ ....................... 655

619.08 Mixing ................................ ................................ .......................... 655

619.09 Placing, Consolidating, and Finishing ................................ .......... 656

619.10 Texturing ................................ ................................ ...................... 656

619.11 Curing ................................ ................................ .......................... 656

619.12 Reconstruc tion ................................ ................................ ............. 657

619.13 Traffic Loading ................................ ................................ ............ 657

619.14 Method of Measurement ................................ .............................. 658

619.15 Basis of Payment ................................ ................................ .......... 658

DESCRIPTION

619.01 Description

This work consists of constructing a polymer modified concrete (PMC) bridge deck overlay fo r the purpose of protecting structural concrete from the deterioration caused by absorption of deicing salts and water. MATERIALS

619.02 Materials

Provide materials as specified in: Portland Cement (Type I or Type III) ................................ .... 901.01 Fine Aggregate (Natural Sand) ................................ .............. 903.01 619.03 651 Coarse Aggregate ( Size 7) ................................ ..................... 903.03 Water ................................ ................................ ..................... 921.01 Use a polymer that appears on the Department’ s QPL.

619.03 Proportioning

Proportion the polymer modified concrete mixture to meet the requirements in Table 619.03 -1 and the following pre -determined proportioning values. Polymer admixture shall be at least 24.5 gallons per cubic yard. Fine aggregate shall be natural sand and proportioned within the range of 1505 to 1785 pounds per cubic yard. The coarse aggregate shall be proportioned within the range of 1176 to 1456 pound per cubic yard. Water, including free moisture on the sand a nd coarse aggregate, shall be proportioned within the range of 56 to 154 pounds per cubic yard. Table 619.03 -1: Composition of Polymer Modified Concrete Mixtures Class of Concrete Min 28-Day Compressive Strength (psi) Min Cement Content (pound per cubic yard) Maximum Water/Cement Ratio (pound/pound) Air Content % (Design + production tolerance) Slump (inches) PMC 4,000(1) 658(2) 0.40 (3) 0-8 4-6 (4)

619.04 Equipment

Obtain the Engineer’s approval as to the design, capacity, and mechanical condition of all equipment and tools necessary for handling materials and 619.04 652 performing all parts of the work. Have the equipment onsite sufficiently ahead of the start of construction operations to allow for the Engineer’s examination and approval.

604.11 Use a volumetric continuous mixing plant that conforms to the

following:

619.05 Limitations

On new structures, deck concrete shall be in place and properly cured before starting overlay operations. Overlay operations may begin as soon as the concrete has gained sufficient strength to resist damage from the blast cleaning. Construct the overlay during favorable weather conditions. Place the mixture when the atmospheric t emperature is between 55 and 75 F. Place concrete in accordance with 604.16. In all instances, place and keep the PMC overlay at a temperature above 45 F for at least 96 hours after placement. Provide approved housing, heating, insulation methods, or some combination thereof, during cold weather. Do not place the mixture when the temperature is 85 F or higher; when the wind velocity is high; when the relative humidity is extremely low; when rain is expected within the working period; or when any other atmospheric conditions cause difficulty in the satisfactory finishing, texturing, or curing of the overlay. This may require night work or other limited work periods. Keep PMC overlay aggregate and sand as cool as possible at the storage site during hi gh temperatures to help prevent cracking in the new overlay. 619.06 655 619.06 Hydro-Demolition Before placing the overlay, hydro -blast the concrete surface to be covered to the depth shown on the Plans. In areas where machine hy dro-blasting cannot reach, in areas of spalling, and where steel reinforcement is exposed, remove deteriorated concrete to sound material using hand tools. Do not use pneumatic hammers heavier than a nominal 45 pounds. After hydro -blasting, clear the deck of all debris. Do not allow traffic on the cleaned portion of the deck.

619.07 Cleaning

After hydro -blasting but before placing the overlay, power wash the entire area of the deck surface with a minimum 10,000 -pound per square inch washing system to pr ovide a bright, clean appearance that is free from laitance, dust, dirt, oil, grease, bituminous material, paint, and all other foreign matter. Perform the hydro -demolition of an area of the deck within the 24-hour period preceding the placement of the ov erlay on the area . Clean the existing deck using a process that will ensure conformance with the air and water pollution regulations applicable to the county or city where the site of work is located and with applicable safety and health regulations. Discontinue use of a ny method that does not consistently produce satisfactory work and conform to the above requirements and replace with an acceptable method. While cleaning, reasonably confine a ll debris of every type, including dirty water, resulting from the cleaning operation . Immediately and thoroughly clean such debris from the blast -cleaned surfaces and all other areas where any escaped debris may have accumulated. Protect the cleaned areas, as necessary, against contamination before placing the overlay. Cover cleaned areas with a plastic cover that will be rolled up as the placement equipment passes over it so that the cleaned surface is not exposed to wheels, dirt, oil, grease , or any other contamin ants. Re-clean contaminated areas and areas exposed more than 36 hours as directed by the Engineer at no cost to the Department.

619.08 Mixing

Mix concrete at the work site, where PMC is to be placed, in accordance with the specified requirement for the equipment used. Do not allow more than 5 minutes to elapse between the completion of mixing and the start of placement operations. Mixing capability shall be such that finishing 619.09 656 operations can proceed at a steady pace with final finishing completed befo re the formation of the plastic surface film.

619.09 Placing, Consolidating, and Finishing

The Contractor may vibrate and finish using approved hand methods in areas that are not accessib le to the finishing machine. Place and fasten screed rails in position to ensure the new surface will be finished to the required profile. Anchorage for supporting rails shall provide horizontal and vertical stability. Do not treat screed rails with part ing compound to facilitate their removal. While placing the PMC, have two water vacuums present for removing excessive water. Finished surface smoothness shall comply with 604.27.

619.10 Texturing

Form transverse grooves in the concrete overlay by mechanical texturing. Form the grooves at an appropriate time during the stiffening of the concrete mixture so that in the hardened concrete, the grooves will be between 0.09 and 0.13 inches in width; between 0.12 to 0.19 inches in depth; and will be spaced at random intervals between 0.3 and 1 inch. The grooves shall terminate approximately 18 inches from curbs, concrete parapets, barrier walls, or other vertical walls. The grooves shall be relatively smooth and uniform. Form the grooves without tearing the surface or without bringing pieces of the coarse aggregate to the top of the surface. Form grooves to drain transversely. Correct areas that do not conform to these requirements using approved methods at no cost to the Department.

619.11 Curing

Promptly cover the overlay surface with a single layer of wet burlap. Avoid using new burlap, as even when pre -soaked, it can dry out quickly. It may be necessary, at the Engineer’s request, to wet the burlap and let it dry out, and then repeat this procedure several times to allow for total absorption. Use white plastic to cover the wet burlap. Consistently spray a mist of water over the burlap before covering it with white plastic; however, ensure that the amount of water sprayed is not so excessive as to damage the fresh overlay surface. 619.12 657 Pull, place, and keep the white plastic within 10 to 30 f eet of the front cover of burlap. Adjust these distances based on the weather conditions at the time of placement. Secure the plastic so that it will not blow off the burlap during the wet cure. Minimize the number of seams in the plastic. Secure the pl astic by using the rails, rolling over the edges of wet burlap onto the plastic, laying folded wet burlap transversely across the deck, or by keeping water on the surface of the plastic. Seal the plastic to prevent the wind from puffing up the plastic dur ing the wet cure. Exercise caution when wetting down the surface of the plastic to prevent the water from running into the overlay being placed. Place soaker hoses under the plastic once the overlay has set long enough to support the weight of the soaker hoses and after the overlay placement is completed. In hot weather, use cold water to enhance these procedures. Place a plastic cover over the deck area after the deck has received hydro - demolition and the deck area has been cleaned. Remove the plastic a s the PMC is being placed.

619.12 Reconstruction

Remove all areas of the overlay that either display a significant number of cracks or that are not intimately bonded to the underlying deck and replace with acceptable concrete at no cost to the Department. Seal all small cracks, which are not significant enough to require removal of the overlay, with a high molecular weight methacrylate sealant at no cost to the Department.

619.13 Traffic Loading

When Type I cement is used, do not allow traffic loading on the new PMC overlaid surface until it has undergone a 24 -hour wet cure and 24 -hour dry cure and has attained a compressive strength of 3,000 pounds per square inch. When Type III cement is used, do not allo w traffic loading on the new PMC overlaid surface until it has undergone a 12 -hour wet cure and a 12 -hour dry cure and has attained a compressive strength of 3,000 pounds per square inch. 619.14 658 COMPENSATION

619.14 Method of Measurement

The Department will m easure PMC by the square yards in accordance with 109. The Department will measure PMC Variable Depth by the cubic yard complete in place , as determined by deducting the theoretical volume of Bridge Deck Overlay (PMC) from the total volume of PMC required to obtain the finished grade shown on the Plans or established by the Engineer.

619.15 Basis of Payment

The Department will pay for accepted quantities at the contract prices as follows: Item Pay Unit Bridge Deck Ove rlay (PMC) Square Yard Polymer Modified Concrete (Variable Depth) Cubic Yard Payment for Bridge Deck Overlay (PMC) is full compensation for placing and finishing the overlay, including providing all tools, labor, equipment, and incidentals for such placeme nt. This item includes only the PMC for the theoretical plan depth of the overlay. The Department will pay for accepted quantities of Polymer Modified Concrete (Variable Depth) at the invoice price of the materials delivered to the Project plus 5%. The i nvoice provided to the Department must reflect the producer’s price used to establish the bid price for PMC and the total quantity of PMC purchased by the Contractor for the entire Project. All other costs associated with placing Polymer Modified Concrete (Variable Depth) are incidental to the price bid for Bridge Deck Overlay (PMC). 620.01 659 SECTION 620 – BRIDGE RAILINGS

620.01 Description ................................ ................................ ................... 659

620.02 Materials ................................ ................................ ...................... 659

620.03 Reserved ................................ ................................ ....................... 659

620.04 Construction Methods ................................ ................................ .. 659

620.05 Method of Measurement ................................ .............................. 660

620.06 Basis of Payment ................................ ................................ .......... 660

DESCRIPTION

620.01 Description

This work consists of furnishing and placing railings for bridges as covered by standard designs or as specially detailed, and includes all reinforcing steel, anchor bolts, or insert sle eves as detailed to support the railing. MATERIALS

620.02 Materials

For the respective type of railing, provide materials as follows: Concrete Parapet with Structural Tubing .......................... STD-11-1 Concrete Parapet ................................ ......... STD-1-1 or STD-1-1SS Concrete Rail ................................ .................... STD-7-1, STD-11-2

620.03 Reserved

CONSTRUCTION REQUIREMENTS

620.04 Construction Methods