STUDY THE EFFECT OF DIFFERENT REINFORCEMENT RATIOS ON THE EXPANDED LIGHTWEIGHT GEOPOLYMER MORTAR PROPERTIES

Abstract

Nowadays, the demand for the production of lightweight construction materials is increasing in order to reduce the cost, which is economically beneficial, as well as reducing the weight of the building as a whole. In this work, a lightweight geopolymer based on fly ash (type F) was developed using an alkaline activator at a concentration of 12 M and the ratio of the activator to the binder was (0.6). The natural sand was partially replaced with expanded perlite (EP), at replacement rates of 10, 30, and 50% by weight. Then the lightweight geopolymer (50% by volume of perlite) was reinforced with polypropylene fiber (PPF) with an addition ratio of (0.25, 0.5, 0.75, and 1%) of the total volume. Laboratory tests were carried out on the produced samples to determine the extent of the properties change after the addition of perlite. The density, insulating and absorbent properties of the lightweight geopolymer composite, which showed a decrease in unit weight with increased porosity and absorbency due to increased interstitial pores, were improved. A clear improvement in flexural strength was also observed when adding 1% polypropylene fibers. As for compressive strength, the improvement was slight. The lower density of the fibers also supports the weight of the unit.