Study on mechanical properties and microstructure of manufactured sand reactive powder concrete with different curing methods

Abstract

To prepare economical and environmentally friendly new cementitious composite materials – reactive powder concrete (RPC) that meets the requirements of field construction. In this paper, RPC was prepared by manufactured sand (MS) as fine aggregate, the compressive strength of MSRPC under natural curing (NC), standard curing (SC) and natural + heat curing (N + HC) were studied, and the microscopic mechanism of MSRPC was analyzed with different curing methods, revealing the relationship between mechanical properties and microstructure of RPC under different curing methods. It lays an important foundation for the widely used of RPC in practical engineering. The results showed that the MSRPC prepared under the three curing methods can meet the performance standards of the actual engineering components, and the compressive strength of the MSRPC under NC and N + HC could reach 85 %–95 % and 101 %–103 % of the SC, respectively. Hot water curing is helpful to the early hydration reaction and generates a large amount of CSH, which reduces the internal porosity of the MSRPC and has a great influence on the early strength.