E FFECT OF E LEVATED T EMPERATURE ON M ECHANICAL PROPERTIES OF F IBER S ELF C OMPACTING C ONCRETE

This study presents the effect of elevated temperature on mass loss ratio, ultrasonic pulse velocity, compressive strength, tensile strength, and flexural strength of self - compacting concrete (SCC) and fiber reinforced self - compacting (FRSCC). Slump flow, T 50 flowing time, L - box and GTM screen stabilities were investigated . The experimental program consist of six mixtures. The control mixture SCC were mad e with out fiber s . The other five mixtures made with added three different types of fiber s (Polypropylene, steel, and glass ). 0.1% Polypropylene fibers , 1% glass fibers and 1% steel fibers by concrete volume were used for PFSCC, GFSCC and SFSCC mixtures respectively. For HFSCC1, 0.05% polypropylene fibers and 0.5% steel fibers by concrete volume were added . For HFSCC2 mix added 0.5% glass fibers and 0.5% steel fibers by concrete volume. The properties of SCC and FRSCC mixtures at 20 °C, 200°C, 400°C, 600°C, and 800 °C were measured after 28 days. The specimens were heated by using electric furnace at a rate of 5 °C /min. The results show that the compressive strength, tensile strength and flexural strength increased with the increasing temperature up to 200 °C and decreased at a temperature higher than 200°C. The PP fibers reduced and eliminated the ri sk of the spalling in the SCC. With increasing temperature t he concrete mixes including steel fibers and hybrid fibers appear the best mechanical properties and spalling resistance . The weight losses for the SCC mixtures with PP and steel fiber were lower than those without PP and steel fibers. In general, fibers decreased fresh concrete properties.