Durability syudies on self cured self compacting concrete

Abstract

Self Compacting Concrete is a special concrete that has been developed to have improved workability without any external compaction. One of the effective methods of improving the self-compacting ability of concrete is to use mineral admixtures to increase the paste content. However, the addition of such mineral admixtures causes shrinkage of concrete. Hence it is necessary to ensure proper curing to avoid cracks due to drying and shrinkage. Internal curing is an emerging concept of curing the concrete from within by means of providing the curing water through materials that can absorb and release water to the surroundings. This research focuses on applying the concept of internal curing to Self Compacting Concrete with Fly ash. Self Compacting Concrete with different percentages of fly ash replacement to achieve M25 grade concrete was designed based on the efficiency factor of fly ash. Two Internal curing materials were selected namely Super Absorbent Polymers (SAP) and fine Lightweight Expanded Clay Aggregates (LECA). The materials were incorporated into the concrete in pre-soaked form with the required amount of water to act as internal curing agents. Three curing regimes were adopted for all the mixes namely conventional water curing without internal curing materials (SCC), Sealed curing by wrapping the specimens in polyethylene sheet (SSAP and SLECA) and Curing under ambient conditions (DSAP and DLECA). Fresh properties such as passing ability, filling ability and segregation resistance were assessed as per the procedures specified in EFNARC guidelines for Self Compacting Concrete with and without internal curing materials. Compressive strength, splitting tensile strength and modulus of elasticity were determined up to 180 days for the concrete mixes under different curing conditions newline