Drying Effect of Normal and High Strength Concrete Cylinders with Different Sizes

Abstract

This paper is a report on a study of shrinkage-weight loss relationships for normal and high strength concrete specimens of different sizes. The maximum aggregate size used in concrete mixes was 10mm. Three geometrically similar test specimens of a cylindrical shape with diameters of 37.5 mm, 75 mm and 150 mm and a height/ diameter ratio of two were used in the experiments. All specimens were subjected to standard air drying in a temperature and humidity controlled laboratory (average relative humidity 50 perpendicular to 6% and temperature 17 +/- 1 degrees C) for a period of 60-70 days. Weight loss and shrinkage measurements were conducted on the specimens prepared with normal and high strength concrete. Results indicated that the time required for the same weight loss ratio was found to be about 7.4 and 8.5 times longer for the largest specimen size than the smallest specimen for normal and high strength concrete respectively.