Shrinkage reducing effect of a combination of internal curing and shrinkage compensating agents on high-performance concrete

Water entraining agent using porous aggregate known as internal curing (IC) has become an important component of high-performance concrete (HPC). This paper presents part of the experimental results of an on-going research project regarding the effectiveness of porous ceramic waste aggregates called 'PorCera' (PC) as IC agent for high-performance structural concrete elements. Previous studies have proven the effectiveness of both the presoaked recycled porous ceramic coarse aggregate (PCCA) as an IC and shrinkage compensating agents in reducing autogenous shrinkage of HPC. The main purpose of this study is to investigate the synergistic effect of a combination of shrinkage compensating agents and the PorCera on silica fume HPC behavior. This hybrid curing technique includes a combination of shrinkage reducing agent (SRA), expansive additive (EA), and internal curing provided by the recycled PC. Its effect on compressive and split tensile strengths, autogenous shrinkage, and internal self-stress were investigated. Results indicate that HPC mixtures made with this hybrid curing system drastically reduce the amount of autogenous shrinkage, and consequently the induced internal stress and perform much betterthan the single incorporation of shrinkage compensating agents.