The erosion of cement paste, mortar and concrete by gritblasting

The paper reports about gritblasting experiments performed on samples of ha rdened cement paste, mortar and concrete. The measurements include mass los s. surface topography analysis, and optical inspections of the eroded surfa ces. Generally, the erosion process is introduced in the interface between the cement matrix and the inclusions. An erosion resistance is defined as t he inverse of the specific volume loss; it shows a good relationship to the product of compressive strength and concentration of coarse aggregates. Sa nd content plays a minor role, but the density has additional influence. Mo rtar has a very low erosion resistance, whereas a light-weight concrete sho ws a comparatively high erosion resistance. The topography of the generated surface depends on the properties of the matrix-aggregate-interface. The l ower the bond, the rougher the surface. The micro-roughness of the aggregat e surfaces increases due to grit blasting, but the adhesion properties, in terms of contact angle, do not necessarily improve. (C) 2000 Elsevier Scien ce S.A. All rights reserved.