WATER-ABSORPTION IN COVER CONCRETE

Measurements of initial water absorption are reported for concretes exposed indoors or outside for 1.5 years. Water absorption after a given wetting time was increased with an increase of water/cement ratio, a reduction of moist curing and partial replacement of the Portland clinker component of the cement. Absorption after outdoor exposure was less than that after laboratory exposure, especially if rain could fall on the concrete surface. Absorption results correlated approximately with weight losses during initial exposure and with compressive strengths at the start of exposure. There was a near-linear relationship between carbonation depths and absorption measured in cover concrete after 1.5 years of exposure.