engleski

Influence of Surface Roughness and Moistness on Adhesion between Concrete and Polymer Modified Mortar

Surface preparation is one of the most important factors in the field of concrete repair. Roughness, as well as moistness of the concrete surface, is supposed to have a great influence on adhesion between concrete and polymer modified mortar. Suitability tests are usually performed on medium rough substrates which are premoistened just before application. It is not clear if these conditions are at optimum. This paper presents laboratory investigations of the influence of surface treatment and influence of different roughness of concrete surfaces on pull-off strength after 7 days. In view of many combinations of surface roughness and moistness, some typical cases are chosen. Index of roughness according to DIN EN 1766 was examined on each concrete plate. Two different types of polymer modified mortar were applied on concrete plates 30×30×10 cm. Also, before the mortar is applied, concrete surface was prepared to be moist (covered with wet sheet 24 hours) or wet (7 days in water) or completely dry. On the basis of laboratory investigations, effects of above mentioned parameters on adhesion between concrete and polymer modified mortar are shown and discussed.

adhesion; moistness; polymer modified mortar; pull-off test; roughness

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