[Longitudinal or transverse] tining; or AstroTurf drag. The texture shall be applied while the concrete is still in a plastic state, but without damaging the surface of the concrete and before application of any membrane curing compound. 5.5 Concrete Curing 5.5.1 Conventional Curing of Panels Once the panel finishing details are taken care of, the panel surfaces and sides shall be sprayed with an approved concrete-curing compound. The curing compound shall be applied within 4 hours of panel stripping. The curing compound used shall be a white-pigmented membrane curing compound from [the Agency]’s approved list. 5.5.2 Steam Curing of Panels Steam curing, at atmospheric pressure, shall be done as a precaster option. When steam curing is used, it shall be done in accordance with industry-accepted standards and include the following items: An initial period of curing, minimum of 3 hours, for the concrete to achieve an initial set before steam curing is initiated. A period for increasing the panel temperature. The temperature in the enclosure surrounding the concrete panels shall not be increased more than 40°F (22°C) per hour. A period for holding the maximum temperature constant, not to exceed 140°F (60°C), measured near the source of steam within the enclosure. A period for decreasing the temperature. The temperatures in the enclosure surrounding the concrete panels not be decreased more than 40°F (22°C) per hour. Once the steam curing has ended, the panels shall not be exposed to the ambient conditions until the concrete has cooled to about 30°F (17°C) above the ambient temperature.
[Longitudinal or transverse] tining; or AstroTurf drag. The texture shall be applied while the concrete is still in a plastic state, but without damaging the surface of the concrete and before application of any membrane curing compound. 5.5 Concrete Curing 5.5.1 Conventional Curing of Panels Once the panel finishing details are taken care of, the panel surfaces and sides shall be sprayed with an approved concrete-curing compound. The curing compound shall be applied within 4 hours of panel stripping. The curing compound used shall be a white-pigmented membrane curing compound from [the Agency]’s approved list. 5.5.2 Steam Curing of Panels Steam curing, at atmospheric pressure, shall be done as a precaster option. When steam curing is used, it shall be done in accordance with industry-accepted standards and include the following items: An initial period of curing, minimum of 3 hours, for the concrete to achieve an initial set before steam curing is initiated. A period for increasing the panel temperature. The temperature in the enclosure surrounding the concrete panels shall not be increased more than 40°F (22°C) per hour. A period for holding the maximum temperature constant, not to exceed 140°F (60°C), measured near the source of steam within the enclosure. A period for decreasing the temperature. The temperatures in the enclosure surrounding the concrete panels not be decreased more than 40°F (22°C) per hour. Once the steam curing has ended, the panels shall not be exposed to the ambient conditions until the concrete has cooled to about 30°F (17°C) above the ambient temperature.
SHRP2_R05_modelspecifications.docx