Latex modified concrete overlays normally requires 48 hours of cure time before traffic can be restored to the structure. It is desirable to minimize the disruption to traffic. High early strength latex modified concrete, as demonstrated by this project, can reduce the cure time.
A 1-1/2 inch overlay of high early strength latex modified concrete was placed on SR5 Overcrossing NE 145th Street bridge No. 513/32, in October 1989. The existing concrete box girder bridge has a deck area of 14,442 sq. ft. The overlay concrete contained Type III cement; the latex was supplied by Dow Chemical USA.
The use of high early strength latex modified concrete can reduce traffic closure time by approximately 24 hours compared to a normal latex modified concrete. The actual bridge closure time will be dependent on the timing of other project activities related to expansion joint repairs or modifications, striping, and off-structure work.