eng Science and Education Publishing International Journal of Materials Lifetime 2017-09-23 3 1 1 8 10.12691/ijml-3-1-1 IJML2017311 article H. H. M. Darweesh hassandarweesh2000@yahoo.com 1 Department of Refractories, Ceramics and Building Materials, National Research Centre, Cairo, Egypt The effect of granulated slag (GBFS), fly ash (FA) and silica fume (SF) substitution by 35 mass% on the physical and mechanical properties of Portland cement mortar was investigated. The results showed that the combined water, bulk density, flexural strength and compressive strength increased gradually with FA content and a further increase was noted when the mortar composite contained equal ratios from the three waste materials. So, it selected to be the optimum mortar composite. The FTIR analysis showed that the free lime content was consumed with FA and SF contents. The SEM images illustrated the formation of abundant fibrous CSH embedded in the matrix due to the hydration and pozzolanic reactions between different components. http://pubs.sciepub.com/ijml/3/1/1/ijml-3-1-1.pdf mortar composite slag fly ash silica fume density strength IR SEM