A study to determine the coefficient of linear thermal expansionof concrete was conducted using concrete mixtures prepared with three types of coarse aggregates: porous limestone, dense limestone, and river gravel. A Type II portland cement was used at contents of 508, 564, and 852 lb/cu yd and water/cement ratios of 0.53, 0.45, and 0.33, respectively. The concrete specimens were moist-cured and tested at 28 and 90 days. The concrete made with the porous limestone had the lowest coefficient of linear thermal expansion, whereas the concrete made with river gravel had the highest. The concrete made with dense limestone had an intermediate coefficient. The water-saturated concrete specimens had a lower coefficient of linear thermal expansion than the oven-dried specimens. The coefficient of oven-dried concrete decreased with moist-curing time. No significant difference between the 28-day and 90-day moist-curing was observed in the water-saturated concrete specimens.
Abstract