The Influence of Different Crystal Modifiers on Ultra-Low Embodied Energy Curing Fiber-Reinforced Cement Composites

Abstract

Fiber-reinforced cement composites (FRCC) are widely used in the construction of houses and commercial buildings in many countries such as the United States, the United Kingdom, the European countries, and the Asian countries such as China, India, and Thailand.  Conventionally, the FRCC is manufactured from Portland cement, silica sand, and cellulose fiber using the so-called autoclaved curing under a designate hydrothermal condition to accelerate the hydration reaction resulting in superior properties.  However, the autoclave-curing process needs a huge investment and generates highly environmental impact specially greenhouse gases due to its heavy energy consumption.  Hence, this research aims to develop the FRCC with lowering embodied energy via the energy-free moisture curing process.  The use of different crystal modifiers (CM) including synthetic tobermorite, alumino-silicate complex, and modified lithium compound in addition of the usual FRCC composition to drive the hydration kinetic and then properties achieved were characterized by the relevance of higher heat of hydration.  Moreover, scanning electron microscope (SEM) were used to reveal the favorable effects of appropriate CM through the microstructure.  The results approved that the FRCC with qualified mechanical performance and densified microstructure was successfully produced by using the appropriate moisture curing condition and CM. Additionally, using alumino-silicate complex as CM at 3% of cement weight produced FRCC with the highest modulus of elasticity of 9,067 ± 492 MPa, and the lowest % water absorption of 27.42 ± 1.65 %.