Mixture proportion of high strength concrete is controled as normal distribution inspite of compressive strength level. This could be following the example of quality control of popular readymixed concrete. There are many unclear point, testing methods and technical factors, that effect on shape of probability distribution of compressive strength in high strength concrete. And additionally, there are scarcely statistical reports of probability distribution of compressive strength in high strength concrete. It was estimated that effects of specimens on probability distribution of compressive strength and propose to mix design of high strength concrete.
