Steam curing is one of the mechanisms used in the precast industry to accelerate the strength gain of structural elements. The values of temperature and time of ideal cures for this strength gain vary with the cement and mix design used in concrete. Little is known about the behavior of self-compacting concrete (SCC) when subjected to the steam accelerated curing process, especially with regards to its mechanical properties. This article evaluates the compressive strength of two mixture designs of self-compacting concrete class 40 MPa with two different cements, cement CP III 40-RS and CP II E-32 submitted to normal curing (I accordance with NBR 5738:2003 [2] and to steam curing. Two different steam curing temperatures were used, at 65°C and 80°C and three curing cycles, 4 h, 6 h and 8 h. The study was done at the Laboratory of Civil Engineering CESP - LCEC - Ilha Solteira/SP, where concretes with specimen cylinders of 10 cm x 20 cm were tested. The compressive strengths were obtained at the end of the steam curing plateau (called immediate strength to the cycle) and at ages 3, 7, 28, 56 and 91 days (called strength at advanced ages) and for concrete subjected to normal curing, the ages of rupture were performed at 3, 7, 28, 56 and 91 days. An analysis of the correlation was performed between the values of rupture of the concrete subjected to normal cure, with the values of immediate strength to the cycle and also to the strength at advanced ages. The benchmarks were performed according to the type of cement used, curing temperature and time in the steam curing plateau. Overall, the results show that the concrete with cement CP II E-32 at 65 ºC, for the steam curing plateau of 4 hours, was the best compressive strength value when subjected to these curing conditions, while the concrete with cement CP III 40-RS at 65 °C, for 6 hours of steam curing plateau, was the optimum strength value.
self-compacting concrete; compressive strength; steam curing; curing temperature; isothermal plateau