Evaluation of Shrinkage and Fracture Properties of Internal Cured 100-MPa Ultrahigh-Strength Steel Fiber–Reinforced Concrete

Abstract

In this paper, shrinkage and fracture properties of 100-MPa ultrahigh-strength steel fiber-reinforced concrete internally cured with presoaked lightweight aggregate (PSLWA) are evaluated through shrinkage and bending tests. The results show that by using PSLWA to partially replace normal-weight aggregates, the shrinkage at 28 days after casting under sealed and dry conditions can be reduced from 600.7 to 274.2 μm/m and from 706.6 to 373.4 μm/m, respectively. However, the introduction of lightweight aggregate (LWA) will lead to reduction of cracking, tensile, and flexural strength even with less negative impact on compressive strength. Adding steel fiber into the high-strength concrete can significantly improve fracture performance of the concrete even at 1% in volume content. These improvements present as increases in displacement at bending peak and in fracture energy determined from their stress-crack opening relationship.