Che Mohd Ruzaidi Ghazali

Study on Fly Ash Based Geopolymer for Coating Applications

Geopolymer is cementitious binders that do not require the presence of ordinary Portland cement (OPC). Fly ash with geopolymer formulations prepared with mixing alumino-silicate with the alkaline activator solution has been applied as protective coating material that suitable for high temperature applications such as fire resistant panel. Geopolymer coating samples were cured at 70 °C for 24 hours before sintered using temperatures range from 600 °C to 1500 °C in order to increase strength and improve thermal properties. Curing conditions also have a significant effect on the development of mechanical strength in most cementitious systems. The chemical compositions, microstructure and FTIR were studied. Geopolymer coating samples cures to a glassy texture and effectively used to create a resistant surface. Fly ash geopolymer coating was improved the compressive strength of the coatings materials as high as 40 MPa. This technology develop a geopolymeric mix design that superior use as cementitious coatings with high thermal application.

Mechanical properties and wear behavior of brake pads produced from palm slag

Brake pads are important safety devices in vehicles. An effort to avoid the use of asbestos in brake pads has led to the development of asbestos-free brake pads that incorporate various organic and inorganic fillers. Palm slag as a filler in brake pads was investigated in this paper. Different processing pressures were employed during production of samples through compression molding. The properties examined included hardness, compressive strength, and wear behavior. The results showed that brake pad samples prepared with 60 tons of compression pressure resulted in the most desirable properties. Hence, palm slag has its own potential for use as a filler in asbestos-free brake pads.

Optimization of Alkaline Activator/Fly ASH Ratio on the Compressive Strength of Manufacturing Fly ASH-BASED Geopolymer

Fly ash and a mixture of alkaline activators namely sodium silicate (Waterglass) and sodium hydroxide (NaOH) solution were used for preparing geopolymer. The aim of this research is to determine the optimum value of the alkaline activator/fly ash ratio. The effect of the oxide molar ratios of SiO2/Al2O3, water content of the alkaline activator and the Waterglass% content were studied for each Alkaline activator/fly ash ratio. The geopolymers were synthesized by the activation of fly ash with alkaline solution at three different alkaline activator/fly ash ratios which were 0.3, 0.35, and 0.4 at a specific constant ratio of waterglass/NaOH solution of 1.00. The geopolymers were cured at 70°C for 24 h and cured to room temperature. Results revealed that the alkaline activator/fly ash ratio of 0.4 has the optimum amount of alkaline liquid, which shows the highest rate of geopolymerization compared to other ratios. A high strength of 8.61 MPa was achieved with 0.4 of activator/fly ash ratio and 14% of waterglass content.

Comparative Study on Thermal, Compressive, and Wear Properties of Palm Slag Brake Pad Composite with other Fillers

The attractive performance-to-cost ratio associated with the incorporation of waste material in composite formulations used to produce brake pads has stimulated the idea of exploring the possible incorporation of additional waste materials in such formulations. Thus, the viability of adding palm slag to the composite formulation used in brake pads was investigated, and the results are reported in this paper. In addition, other fillers, such as calcium carbonate and dolomite, were used for comparative purposes. The properties examined included thermal properties, compressive strength, and wear behavior. The results showed that palm slag has significant potential for use as an alternative to the existing fillers in the composite formulations used to produce brake pads.

Mechanical Properties and Morphology of Palm Slag, Calcium Carbonate and Dolomite Filler in Brake Pad Composites

The development of asbestos free brake pad composites using different fillers was investigated with a intention to substitute asbestos which is known hazardous and carcinogenic. Mechanical and morphology studies were made to clarify the mechanism for compressive strength, hardness and wear rate behavior of different filler of brake pad which were prepared by compression molding of mixture of filler (palm slag, calcium carbonate and dolomite) with phenolic as binder, metal fiber as reinforcement, graphite as lubricant and alumina as abrasive. The result showed that palm slag has significant potential to use as filler material in brake pad composite. The wear rate of palm slag composite was comparable with the conventional asbestos based brake pad. The result also supported by SEM micrograph.

Application of clay - based geopolymer in brick production: A review

This paper reviews and summarizes the current knowledge and application of clay as a geopolymer material in production of geopolymer brick. As we understand, the nature of source materials give a significant impact to the strength of geopolymer. For example, geopolymer made from calcined source material such as calcined kaolin, fly ash, ground granulated blastfurnace slag (GGBS) and others produce a higher compressive strength compared to geopolymer made from non-calcined source material such as kaolin. This paper is reviewing on the suitability of clay application as a geopolymer material in geopolymer brick production. The chemical composition of clay-based material show high content of SiO2 and Al2O3 compound which is similar to the fly ash. Clay-based Geopolymer showed a good potential in a brick production.

Nano Geopolymer for Sustainable Concrete Using Fly Ash Synthesized by High Energy Ball Milling

This paper presents the development of a nano geopolymer for sustainable concrete using fly ash synthesized by high-energy ball milling. In this paper, we report on our investigation of the effects of grinding on the binder properties and the optimization of the mix design for nano geopolymer paste. The research methodology consisted of synthesizing fly ash by using a high-energy ball mill to create nanosized particles and determining the formulation and mix proportions required to produce a nano geopolymer paste with the addition of an alkaline activator. The ratio of fly ash to alkaline activator and sodium silicate to sodium hydroxide were constant for the entire experiment which is 2.5. Ball milling was conducted for the total duration of six hours, during which particle size was reduced from 10 μm to 60 nm. The nano geopolymer were cured at temperature 70°C and then tested on 1st day and 7th day for compressive strength. Scanning electron microscopy (SEM) was used to characterize the shape, texture, and size of the milled fly ash.

Influence of Solidification Process on Calcined Kaolin Geopolymeric Powder

This paper aims at investigating the influence of solidification condition on the processing of calcined kaolin geopolymeric powder. This is a new process developed using the geopolymerization process. Geopolymer slurry was prepared from calcined kaolin and activating solution (mixture of NaOH and Na2SiO3). This slurry was allowed to solidify in oven and then crushed and grounded to fixed particle size. Compressive testing and SEM analysis were performed in this study. The results showed that the solidification condition at 80 °C for 4 hours was the best to synthesize the geopolymeric powder where this solidification condition results in geopolymeric powder which can produce higher strength resulted geopolymer paste. The microstructure showed more intervening gel phase which indicates that the geopolymerization process continued to react after the addition of water to the calcined kaolin geopolymeric powder.

Curing Behavior on kaolin-based geopolymers

This paper aims at investigating the influence of curing process on kaolin-based geopolymers. Kaolin-based geopolymers were prepared by the alkali-activation of kaolin with alkali activating solution (mixture of NaOH and Na2SiO3 solutions). The compressive testing, XRD and FTIR analysis were performed. The compressive strength results showed that curing at 60°C for 3 day achieves better strength. XRD analysis revealed that the entire geopolymer sample reduced in intensities and became amorphous at longer age while FTIR analysis indicated the presence of geopolymer bondings. Both analyses showed the presence of large amount of un-reacted remained in the system were the reason of the low compressive strength obtained.

New Processing Method of Kaolin-Based Geopolymer Brick by Using Geopolymer Brick Machine

With increased activity in construction, deficiency of building materials and construction waste improvements have encouraged the development of new building materials. Conventional construction bricks are usually made from clay and sand, which are mixed and molded in various method and need to be dried and burned. Geopolymer bricks making process consume less energy and low cost in term of production compared to conventional bricks. The development of geopolymer brick is an important step towards produce bricks with better performance and environmental friendly material This research focusing on the processing process of the clay-based geopolymer brick from the mixing until the curing by using a geopolymer brick making machine.