Thermal Properties of Green High-Performance Fiber-Reinforced Cementitious Composites Subjected to High Temperature

Abstract

To study the influences of mix proportions and high temperature on the thermal properties of green high-performance fiber reinforced cementitious composites (GHPFRCC), sixteen mix proportions were designed using the Taguchi orthogonal method. Five variables investigated were the water-to-binder ratio (0.24, 0.28, 0.32, and 0.36), sand-to-binder ratio (0.36, 0.46, 0.56, and 0.66), polyvinyl alcohol (PVA) fiber content (1.5%, 1.7%, 2.0%, and 2.2%) by volume, fly ash replacement (60%, 65%, 70%, and 75%) by weight, and the superplasticizer content (0.10%, 0.15%, 0.20%, and 0.25%). Each GHPFRCC specimen was subjected to a target temperature (200 °C, 400 °C, 600 °C, and 800 °C), and then measured for its thermal conductivity using a transient plane source method. The experimental results showed that the thermal conductivity of GHPFRCC decreased dramatically in the initial stage up to 400℃, then slowly decreased with temperature until 800℃. Compared with normal concrete, the GHPFRCC is relatively low in thermal conductivity and, therefore, can be used as a better thermal insulation material for infrastructures.