Mechanical behavior of mortars containing sewage sludge ash (SSA) and Portland cements with different tricalcium aluminate content

The influence of sewage sludge ash (SSA) on cement mortars strength has bee n studied. To evaluate better the increase of strength compared to control mortar, relative compressive strength gain (CSGr) and flexural strength gai n (FSGr) were calculated. The experience shows that SSA behaves as an activ e material, producing an increase of compressive strength compared to contr ol mortar, probably due to pozzolanic properties of SSA. It can be emphasiz ed that high sulfur content of SSA (12.4%) does not seem to have influence on compressive strength of mortars containing SSA. When CSGr of mortars con taining different types of cements are compared, no clear correlation is ob served between CSGr and C(3)A content in cement. (C) 1999 Elsevier Science Ltd. All rights reserved.