Investigation on physico-mechanical, durability and thermal properties of hemp fibre reinforced foam concrete containing fly ash and Taguchi optimization approach

This study presents the investigation on physico-mechanical, durability and thermal properties of hemp fibers (HF) reinforced foam concrete containing fly ash (FA) and Taguchi optimization approach. Three series of foam concretes mixtures were produced with the foam contents of 50 kg/m3, 75 kg/m3 and 100 kg/m3. Each foam concrete mixtures includes reference mixture without HF and FA and other mixtures contain FA as cement replacement at the rates of 0%, 10%, 20%, 30%, 40% and 50%. HF with varying fiber length were also added to the mixtures at the inclusion rates of 0,75%; 1,5% and 3% by weight of cement. Slump tests were conducted to assess the fresh properties of mixtures. The strength properties were determined using 7, 28 and 91 day-compressive and flexural strength tests, while durability was investigated by high temperature, freeze-thaw and sulphate exposures. Thermal conductivity, drying shrinkage, porosity, water absorption, sorptivity and dry unit weight properties of foam concretes were also investigated. Experimental results were analyzed using Taguchi optimization approach. Results showed that addition of HF resulted in very high compressive and flexural strength enhancements. FA addition reduced the drying shrinkage and thermal conductivity and increased the high temperature resistance of foam concretes. KEYWORDS:Foam concrete; fly ash; hemp fibers; physico-mechanical properties; durability properties; Taguchi optimization