THE EFFECT OF USING LIME, SILICA FUME AND NANO-SILICA ON MORTAR MADE FROM SEA SAND AND SEAWATER

Abstract

The need for natural sand (RS) and freshwater (FW) is not proportional to the existing supply, so substitute materials are needed to meet these needs. Seasand (SS) and seawater (SW) are materials that have the potential as substitute materials which have not been utilized so far. The main obstacle to the use of these materials in mortar and concrete is due to the sodium chloride (NaCl) content which can cause corrosion of the reinforcement. This research is an innovation to overcome the NaCl content mixed with materials: Cement (PC), lime stone (LS), silica fume (SF), nano-silica (NS), and superplasticizer (SP) mixed proportions with a volume ratio, cured with SW and FW. The goal is to produce the optimal composition for the use of SS and SW in mortar. For this reason, tests for water content, organic content, compressive strength, porosity, and X-Ray Fluorescence (XRF) and Metrohm 916 Ti Touch Auto Titrator were carried out. The results showed that the optimal mix proportion was 1 PC : 1 SS : 3.75 LS : 1.125 SF : 0.5625 NS : 0.4 SP achieving a compressive strength of 16 MPa (42.4%) from the control mortar (freshwater curing) and 14 MPa (40.4%) (seawater curing). BL is better than MC the NaCl content decreased from 0.32% to 0.25% and increased porosity by 35%. The benefits of this study show that SS and SW can be used as environmentally friendly construction materials.