STUDY ON ESTIMATION METHOD FOR STRENGTH OF CONCRETE IN STRUCTURES BY SMALL SIZE CORES : Part1 Results of compressive strength test of small size cores

Abstract

There is not much possibility of damaging concrete in structures by sampling the small size cores whose diameters are from 18 to 25mm. In the present paper, the results of compressive strength test by small size cores and standard size cores which are 100mm in diameter and 200mm in height are discussed. Test results are summaried as follows : 1)Small size cores show different pattern of fractures according to the location of coarse aggregates, 2)the estimaton method by small size core has practical merit due to sampling efficiency, 3)the difference of strength of small size cores from that of standard size cores is almost constant.