The erosion of cement paste, mortar and concrete by gritblasting

The paper reports about gritblasting experiments performed on samples of hardened cement paste, mortar and concrete. The measurements include mass loss, surface topography analysis, and optical inspections of the eroded surfaces. Generally, the erosion process is introduced in the interface between the cement matrix and the inclusions. An erosion resistance is defined as the inverse of the specific volume loss; it shows a good relationship to the product of compressive strength and concentration of coarse aggregates. Sand content plays a minor role, but the density has additional influence. Mortar has a very low erosion resistance, whereas a light-weight concrete shows a comparatively high erosion resistance. The topography of the generated surface depends on the properties of the matrix-aggregate-interface. The lower the bond, the rougher the surface. The micro-roughness of the aggregate surfaces increases due to grit blasting, but the adhesion properties, in terms of contact angle, do not necessarily improve.