250 joints, approximately twelve ( 12) to twenty -four ( 24) inches from the outside edge o f the pavement. Station numbers shall be placed along the right edge of a two -lane highway, readable in the direction of increasing stations. On multi -lane highways, numbers shall be placed along the outside edge of the two outside lanes of the roadway, readable in the direction of travel.
501.12.10 Protection Against Rain: In order that the concrete may be properly protected
against the effects of rain before the concrete is sufficiently hardened, the Contractor shall have available at all times mate rials for the protection of the edges and surface of the unhardened concrete. Such protective materials shall consist of metal forms or wood planks having a nominal thickness of not less than two ( 2) inches and nominal width of not less than the thickness of the pavement at its edge for protection of the pavement edges, and covering material such as burlap or cotton mats, curing paper, or plastic sheeting for protection of the surface. When rain appears imminent, all paving operations shall stop and all a vailable personnel shall begin placing forms against the sides of the pavement and covering the surface of the unhardened concrete with the protective covering.
501.13 Surface Tests :
The smoothness of the riding surface will be determined using the procedures outlined in Section 720. When corrective action is needed, the diamond grinding operations shall be in accordance with section 508.
501.13.1 Sampling Units: The pavement will be divided into sampling Lots of 0.1 lane
mile each. Each Lot shall exhibit a smoothness measurement, expressed in inches per mile.
501.13.2 Smoothness Requirement: Each sampling unit shall exhibit a smoothne ss equal
to or less than sixty -five ( 65) inches per mile. Sampling units exhibiting smoothness values greater than sixty -five ( 65) inches per mile shall be paid for at an adjusted price as follows: Revised Unit Price = UBP – [(1.00 -{127.86 -0.429S }) (0.18 UBP)] Where: UBP = Unit Bid Price S = Smoothness in inches per mile When the measured smoothness value exceeds the specified value by 50 percent (50%) or more, the Lot shall be corrected to comply with these specifications.
501.13.3 Grinding Requirements: When the pavement requires corrective action as
noted above, the diamond grinding operations shall be in accordance with section 508, except that the final pavement smoothness requirements shall be in accordance with section 501.
501.14 Curing :
Immedia tely after the finishing operations have been completed and as soon as marring of the concrete will not occur, the entire surface of the newly placed concrete shall be cured in accordance with one of the methods described. 251 In all cases in which curing requ ires the use of water, the curing shall have prior right to the use of all water supplies. Failure to provide sufficient curing materials of whatever kind the Contractor may elect to use will be cause for immediate suspension of concreting operations. Th e concrete shall not be left exposed for more than 30 minutes between stages of curing or during the curing period. Concrete placed in cold weather, as defined in 501.21, shall be cured a minimum of seven calendar days or when the Contractor provides suit able means for documenting the maturity (degree -hours) of the concrete, based on slab surface temperature, the curing period may be terminated when the curing has been maintained for a minimum of 7,000 degree hours. During the curing period the surface te mperature of the concrete shall not be allowed to fall below freezing. The Contractor shall be responsible for the quality of the concrete placed or cured, or both, during cold weather. Any concrete injured by frost action shall be removed and replaced a t the Contractor's expense. Polyethylene coated burlap and white polyethylene sheeting will be permitted as a curing application only on areas where intimate contact with the concrete surface can be obtained and maintained.
501.14.1 Burlap Mats: The s urface of the pavement shall be entirely covered with the
mats. The mats shall be of such length that they will extend at least twice the thickness of the pavement beyond the edges of the slab. The mat shall be placed so that the entire surface and both edges of the slab are completely covered. Before placing, the mats shall be thoroughly saturated with water. The mats shall be weighted down so as to remain in intimate contact with the surface covered and shall be maintained fully wetted and in pos ition for 72 hours after the concrete has been placed, unless otherwise specified.
501.14.2 Waterproof Paper: The top surface and sides of the pavement shall be entirely
covered with waterproof paper. The units shall be lapped at least eighteen ( 18) inches. The paper shall be weighted down so as to remain in intimate contact with the surface. Each unit as laid shall extend at least twice the thickness of the pavement beyond the edges of the slab. Paper not manufactured in sizes providing this width shall be securely sewed or cemented together, the joints being securely sealed in such a manner that they do not open up during curing. The surface shall be thoroughly wetted before placing the paper. Curing shall continue for 72 hours after the concrete is placed, unless otherwise specified.
501.14.3 Straw Curing: When this type of curing is used, the pavement shall be cured
initially with burlap or cotton mats, as specified above, until after final set of the concrete or, in any case, for 12 hours a fter placing the concrete. As soon as the mats are removed, the surface and sides of the pavement shall be thoroughly wetted and covered with at least eight (8) inches of straw or hay, thickness to be measured after wetting. The straw or hay shall be kep t thoroughly saturated with water for 72 hours after placing the concrete. If the straw or hay becomes displaced during the curing period, it shall be replaced to the original depth and saturated. Upon removal, the covering shall be disposed of in such a manner as to leave the right -of-way in a neat condition. The straw or hay shall not be burned on, or adjacent to, the pavement.
501.14.4 White Pigmented Impervious Membrane : The entire surface of the pavement
shall be sprayed uniformly with white pigmented curing compound immediately after the finishing operation and before initial set has taken place, or, if the pavement is initially cured