Variation of concrete crack widths through the concrete cover to reinforcement

The determination of the relationship between the width of main cracks at the steel surface to that at the external concrete surface is reported. A series of tests was carried out for this purpose on specimens that simulate the part between two adjacent cracks on a long reinforced concrete tension member. Measurements were taken of the concrete surface strains, the extension of steel embedded in concrete and the relative slip between steel and concrete under increasing load.