Abstract
In this report the results of experimental studies are shown with respect to the rough discriminations on quality of shape of crushed stone as coarse aggregate used in steel structure encased in reinforced concrete and adjustments on mixing proportion of AE crushed stone concrete based on that of AE gravel concrete. The outlines of results are shown in the following: (1) As the rough discriminations on qualities of shape of crushed stone, we are studied in the following methods: (a) A method of surface area ratio (b) A method of sieve analysis (c) A method of direct observation, which consists of comparing given crushed stone with photographic samples of coarse aggregates having preknown surface factors (surface factor is (surface area of crushed stone)/(surface area of gravel) per unit weight). (2) Relations between qualities of shape of crushed stone and means of crushing, and these relations depend on compressive strength of stone especially. (3) Adjusting factors used for the perpose of determining for mixing proportion of AE crushed stone concrete based on that of AE gravel concrete. (4) In Japan, Hamada's formula being generally used to the relations between compressive strength (28 days) and c/w of non-AE gravel concrete, is not so inconvinient in practical use for AE crushed stone concrete.
