An In-Situ Study on The Specimen Size Effects on Compressive Strength for Different Strength Concretes

Abstract

The compressive strength of concrete is the most basic and considerable material property while reinforced concrete structures are designed. It has become a problem to use this value, however, because the control specimen sizes and shapes from country to country may be dissimilar. The study presents the results of an experiment that examined the effect of specimen size on the different classes of compressive strengths of concrete. The study included casting specimens, cubes, and six different classes of the concrete mixture. Compression tests were conducted at the age of 3, 7, and 28 days on 150 mm & 100 mm cube samples. The fresh properties of concrete were measured by slump and unit weights tests. Moreover, the specimen size of concrete has an important role both on the compressive strength and capacity of a curing cabinet. Correlations between compressive strengths and sizes of specimens are compatible for classes of structural concretes. Therefore, it can be used in curing cabinet varying sizes of concretes like 150 mm & 100 mm cube samples. Although almost 220 concrete specimens sized of 150 mm cube can be poured in curing tank, roughly 585 concrete specimens can be poured with using 100 mm cube concrete specimens. The most convenient size resulted from this study is suggested as 100 mm sized cubic specimen that it promote to change the law for concrete both curing and compressive strength test.