Influence of curing regime on properties of reactive powder concrete containing waste steel fibers

摘要

Reactive powder concrete (RPC) has excellent mechanical properties and durability, but its excellent properties are mainly obtained by selecting materials (high cost) and complicated curing process. From the point of view of reducing production cost and optimizing properties, we used waste steel fibers to replace traditional copper-coated steel fibers to prepare reactive powder concrete, and focused on the influence of curing regime on the properties of reactive powder concrete containing waste steel fibers. Through strength test, X-ray diffraction, scanning electron microscopy and mercury intrusion porosimetry analysis, it is concluded that high temperature steam curing makes RPC have higher strength and denser microstructure in comparison with ambient temperature curing, but hot air curing can make hydration products appear crystallization and increase porosity. High temperature steam curing at 80-90 degrees C for 2-3 days is proper. Appropriate pre-curing can further increase the strength of RPC, and the optimum curing regime for better compressive strength is water pre-curing for 2 days and then high temperature steam curing at 80 degrees C for 2 days. (C) 2019 Elsevier Ltd. All rights reserved.