Flexural strength tests on small concrete beams at ages up to ten years and fatigue tests up to five years are reported. Tests were made on three types of concrete, two containing flint gravel aggregate, the other containing crushed limestone. Two of the concretes were of pavement quality and the other was a dry lean mix. In each case substantial increases in both static strength and fatigue performance were observed, with a modest increase in modulus of elasticity. The flexural strength increased more rapidly than the compressive strength. Increases in fatigue performance closely reflected changes in flexural strength; if the fatigue loading is expressed in terms of the flexural strength at the appropriate age the results of all the fatigue tests, on all three concretes, fall close to a single fatigue endurance curve. This can be used as a basis for estimating the approximate mean fatigue life at any applied stress level at any given age. (Author/publisher)
Samenvatting