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

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 degrees C, 400 degrees C, 600 degrees C, and 800 degrees 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 degrees C, then slowly decreased with temperature until 800 degrees C. 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.