The High Temperature Effect on Fibre Reinforced Self Compacting Lightweight Concrete Designed with Single and Hybrid Fibres

The purpose of this paper is to declare the results of investigation conducted on design of fibre reinforced self compacting lightweight concrete which has three different concrete technologies, and high temperature effect on it. For this aim, it is desired that production of new kind concrete material composed of fibre reinforced concrete, self compacting concrete and structural lightweight concrete technologies using all their better benefits. In this study, fly ash was used as a powder to reduce Portland cement consumption as well as CO_2 emission through the use of that waste material. A control self compacting concrete and 7 fibre reinforced self compacting lightweight concretes were designed applying slump flow (T50-flowing time and flowing diameter) and V-funnel tests to determine fresh concrete properties. In the design of fibre reinforced self compacting lightweight concrete, both single and hybrid fibre reinforced self compacting lightweight concrete mixes were produced using 1 macro and 1 micro steel fibres in different lengths and aspect ratios. Hybrid fibre reinforced self compacting lightweight concrete mixes were prepared using macro fibres together with micro fibre at three different percentages (50%-50%, 25%-75%, 75%-25%) by weight. After design process, cubic and prismatic concrete specimens were produced to determine hardened properties at standard concrete age. Firstly, flexural tensile and compressive strength tests were performed on the concrete specimens on 28 day. Lastly, the concrete specimens were heated up to temperatures of 200, 400, 600 and 800C then compressive strength and flexural tensile tests were performed to identify high temperature effect comparing to strength test results obtained from standard laboratory conditions. The test results showed that concrete mixes including macro fibres gave the best tensile strength properties, although they gave the worst fresh concrete properties.