The purpose of this work was to study the microstructure and the mechanical properties of the fiber-reinforced cement composites that used the nucleating-agent activated coal-fired power plant bottom ash as a raw material in the mixture for producing the composites. The raw materials for producing the fiber reinforced cement composites were the ordinary Portland cement (OPC), natural gypsum, cellulose fiber, and bottom ash. The bottom ash was chemically treated by the nucleating agent, a chemical that was prepared by the precipitation process from the aqueous solutions of sodium silicate (Na2SiO3) and calcium nitrate (Ca (NO3)2). To prepare the samples, the mixture consisting of 34.75 wt% OPC, 34.75 wt% bottom ash, 25 wt% natural gypsum, and 5.5 wt% cellulose fiber was mixed with the nucleating agent at the amount of 0 to 4.5 % of OPC weight in the mixture, and water to form the slurry. Then, the samples were produced by filter pressing process and cured in the autoclave for 16 hrs at 180 °C, and 10 bars. The mechanical properties of the samples including modulus of rupture (MOR), modulus of elasticity (MOE), and toughness were characterized by the universal testing machine (UTM). The microstructures of the samples were observed by scanning electron microscope (SEM). The results showed that the utilization of nucleating agent affect the microstructure of the sample leading to the improvement in the mechanical properties of samples.

Around 3 million tons of municipal solid wastes called bottom ash (BA) are produced annually from the coal-fired power plants and it is still much underutilized in Thailand.  Hence, the increasing usage of BA in industrial scale is necessary to limit the environmental impacts from landfilling of those by-product. Using of BA in fiber cement (FC) manufacturing seems to be a promising one.  However, several negative effects regarding the extremely high water content from the fiber-cement forming process (Hatschek process) and the BA characteristic (the creation of bubble network) need to be eliminated.  Both mentioned inferiors significantly reduce the cement hydration mechanism leading to remarkable reductions of set and hardened performances of fiber cement.  Therefore, chemical treatment (CT) was introduced to boost up the hydration kinetic and characterized via the relevance of higher heat of hydration.  Additionally, scanning electron microscope (SEM) was used to reveal the beneficial effects of treated BA through the microstructures. The results showed the chemically treated BA improve kinetic of hydration reaction was from the modification of BA surface.

Due to more strict environmental protection and greenhouse gas reduction, it is very important for all industries to appropriately manage their energy consumption.  Fiber- reinforced cement composites are the popular building materials which consume enormous energy to intensify its chemical reaction during the autoclave steam curing process. Utilization of chemical admixture to replace the conventional energy-driven autoclave steam curing process will support the fiber- reinforced cement composites industry to develop sustainable building materials.  In this research, typical and mechanical properties of the air-cured fiber- reinforced cement composites incorporated with alumino-silicate based accelerator were investigated.  The results show an excellent positive correlation between the water-cement ratio of the mix design and the mechanical strength which is the optimum water-cement ratio for this FRCC are 0.53. Moreover, the properties of fiber- reinforced cement composites cured by either the autoclave steam curing process or air-curing process are comparable.

The performance of cement mortar can be improved with additives based on waste by-products. Synthetic zeolite polymer composites (referred as SZPC) produced from the combination of solid waste ashes with a selective acrylic compound was used as a cement mortar additive. The effect of SZPC as an additive on hydration reaction of ordinary Portland cement (referred as OPC) at different amounts of SZPC, from 1-4% of OPC weight, as well as microstructure and mechanical behavior of the cement mortar are determined. The results from the hydration reaction rate test showed that the optimum amount of SZPC as the additive was 2% of OPC weight. Compressive strength and flexural strength of the cement mortar after 1, 7, 14 and 28 days of curing increased, with the largestincreases at the early stage. Additions of SZPC, synthesized by a waste by-product, improved mechanical behavior of cement mortars supporting sustainable development and the circular economy.

Two different pore modifiers (PM), artificial pozzolan (AP) and modified aluminum salt (MA), were introduced into the composition of a High Performance Cement Mortar (HPCM). The chemical compositions of raw materials, ordinary Portland cement (OPC), sea sand, AP, and MA were identified by X-Ray Fluorescence spectrometry (XRF). The hydration kinetics resulting from each PM added to the HPCM was investigated by the relevance of hydration temperature. The mechanical properties such as compressive strength, dynamic modulus of rupture, and dynamic modulus of elasticity were measured as well as water absorption and density. Additionally, Scanning Electron Microscope (SEM) and Brunauer-Emmett-Teller (BET) were used to reveal the beneficial effects of appropriate PM through the microstructure, pore size distribution and specific surface area. Experimental results showed that the PM increased the hydration temperature, resulting in the generation of stress at early stages throughout the HPCM structure. This stress caused the formation of micropores, which increased water absorption, decreased density, and enhanced the structural integrity