Characteristics of sustainable high strength concrete incorporating eco‑friendly materials

摘要

This research investigated the effect of silica fume (SF), rice husk ash (RHA), and blast furnace slag powder (BFSP) as supplementary cementitious materials on different concrete properties of sustainable high strength concrete (SHSC). Thirteen different SHSC mixtures (f(c) = 69.7 to 102.1 MPa) without and with SF, RHA, and BFSP were prepared with obtainable materials in Egypt. SHSC mixtures were cast with 0, 5, 10, 15, and 20% cement replaced by either SF or RHA, or BFSP. Performances of RHA mixes were compared with control mixes and mixes incorporating SF and BFSP. Scanning electron (SEM and EDX) was used to measure the microstructure characteristics of RHA. The mixtures were tested for the slump, air content, mechanical properties, and water permeability. Test results have indicated that SF exhibits higher pozzolanic activity than RHA and BFSP, while mixtures with BFSP showed a better consistency than SF and RHA concrete mixes. In addition, the results of mechanical properties indicate that the optimum level for partial replacement of cement by SF and RHA was 15% and 10%, respectively. The compressive strength and other mechanical properties of concrete with SF and RHA were higher than that of control concrete. The use of Eco-friendly materials as supplementary cementitious materials will yield economic and environmental benefits, particularly from the perspective of sustainable development.