Thermal expansion of self-consolidating normal and lightweight aggregate concrete at elevated temperature

In this study, the effects of aggregate type on the coefficient of thermal expansion of self-consolidating concrete produced with normal (SCC) and lightweight aggregate (SCLC) at elevated temperature were investigated. In experiments, two aggregate types, crushed limestone and pumice, were used. Different combinations of water/powder ratio and superplasticizer dosage levels were prepared for the SCC and SCLC mixtures. The total powder content (cement and mineral additives) was constant in the experiments. Thermal test was performed to accurately characterize the coefficient of thermal expansion (CTE) of SCC and SCLC aged 28 days using the dilatometer. The CTEs of SCC and SCLC were defined by measuring the linear change in length of concrete specimens subjected to a range of temperatures. Test temperatures were varied from 20 to 1000 °C at a heating rate of 5 °C/min. The results, in general, showed that SCC has higher CTE than normal weight concrete and that lightweight aggregate reduced the CTE of SCC due to their porous structure. The aggregate type has significant influence on the thermal expansion of SCC.