抄録
This is the report on the compressive, tensile and flexural tests in high rates of loading on the eight kinds of concretes, specified with their aggregates and admixtures. The loads were applied at stress rates ranging from those of static tests to about 10^5kg per sq cm per sec. Both load and strain were measured by means of wire strain gages, and recording of the data were made with six elements cathode ray oscilloscope. From these tests, the following results were observed. On Compressive Tests; The failure of most specimens occurred abruptly as soon as their stress reached the ultimate strength. Compressive strength, strain measured at the maximum stress, modulus of elasticity and absorbed energy of each of the concretes increased with the rate of application of the load. Poisson's number of these concrete also showed the same tendency. On Tensile Tests; The tensile strength of each of the specimens produced by the splitting tests increased markedly with the rate of loading and the strains observed at failure in the high rate tests were substantially greater than the corresponding strains in the static tests. On Flexural test; The flexural strength of each of the concretes increased significantly with the loading rate. The neutral axis of the specimens held a nearer position to the surface of the Compressed part in the tests of the highest rate of loading than that in the static tests.
