Abstract
In this paper the author deals with the application of the estimation method of early compressive strength of concrete presented in former paper, that is the relation between the properties of author's formula for early concrete and the others' formula for hardened concrete and the application of the author's formula to the experimental resuts by the author's done after the former paper and by the other authors', and it is confirmed that the other authors' formulas are not applicable to the estimation of early strength of concrete. Furthermore, the author's formula is applicable to large extent of early concrete without any compensation. The conclutions are as follows. (1) Deviation of strength by author's method for early concrete is smaller than that by the other anthor's method for hardened concrete. (2) The curves of coefficient N_<20> (coefficient of curing temperature based on 20℃) by author takes place in midway between the curves of Rastrup's hydration formula and D・D method in which the origin of curing temperature is -10℃. (3) The formula for hardend concrete is not applicable to the development of early strength of concrete. (4) The author's method is well applicable to the sixteen the others' experimental resuts on the early strength of concrete. (5) The author's method is applicable to estimate the early strength in large extent of concrete without any compensation of coefficient of formula, for instance, concretes which are used several type of cements, several kinds of admixture, light weight aggregates, crushed stone and different size of sand, and which are varied mixing proportion in large extent.
