Effects of expanded perlite aggregate and different curing conditions on the drying shrinkage of self-compacting concrete

摘要

Fresh self-compacting concrete (SCC) flows into place and around obstructions under its own weight to fill the formwork completely and self-compact, without any segregation. The present study investigates drying shrinkage of SCC including mixtures of expanded perlite (EPA) and natural aggregates (NA) at six different curing conditions. The binder dosage is kept constant at 450 kg/m~(-1) throughout the study. A superplasticizer is used as 2 percent (by weight) of Portland cement (PC) to reduce water/cement+mirieral (w/cm) ratios and self-compacting. Specimens have been exposed to conditions of lime-saturated water (B1), dry in air (B2), coated with paraffin (B3), three times wetted in a day (B4), under wet-sack (B5) and 100 percent relative humidity (B6). It has been found that drying shrinkage of concrete is reduced by using EPA. The drying shrinkage of EPA concrete decreases with an increasing moisture content. It is also found that concrete exhibits a lower drying shrinkage in all time periods under the B1 curing conditions.