Abstract
Type: Abstract
In this paper, durability index test methods were employed to assess the influence of repair materials on the durability of concrete. Five (5) commercially available repair materials were studied viz:- two special coatings of masonry and carbothane aliphatic paints, and three repair mortars consisting of general purpose, cement-based, and epoxy resin. The oxygen permeability and the water sorptivity test methods were used to determine and compare the performances of the various repair materials. In addition, three types of substrate surface preparation methods were investigated namely chiseling, cutting and brushing of the substrate. The results of the tests show that repair materials do have significant effect on increasing the durability of concrete. It was found that substrate preparation is an important factor in making a durable repair with wire brushed surface preparation giving best performance and chiseling giving least improvement in results. The epoxy resin repair material uniquely showed water-repellant properties in the sorptivity test, not typical of common concrete material behaviour. Accordingly, the applicability of the index test methods on testing of repaired concrete surfaces in the field may require prior knowledge of the characteristics of the repair material used in order to aid interpretation of their durability index test results