REVIEW OF THE FLEXURAL STRENGTH OF LIGHTWEIGHT CONCRETE BEAM USING PUMICE STONE AS OF SUBSTITUTION PARTIAL COARSE AGGREGATE

Abstract

This research was conducted to analyze the flexural behavior of unreinforced concrete beams produced by substituting coarse aggregate with pumice stones in order to reduce the weight. The specimens used were designed to be 15x15x70 cm in dimension while the coarse aggregate was replaced by the pumice stone at 25%, 50%, 75%, and 100%. Test object without pumice stone (0%) as control beams.The test was conducted at a two-point load with the beam loaded up to the period it failed. The results showed the partial substitution of a higher percentage of the coarse aggregate with pumice produced lower flexural capacity and the beams become lighter with the weight recorded to have reduced by 20.05%. This means the partial replacement of more coarse aggregate with pumice stone has the ability to reduce the weight of the beam and its flexural strength.The use of pumice as a substitute for coarse aggregate in unreinforced concrete beams against tensile strength is good because the tensile strength tends to be higher than the tensile strength of concrete in general.