Geopolymer concrete has the potential to replace ordinary Portland cement which can reduce carbon dioxide emission to the environment. The addition of different amounts of steel fibers, as well as different types of end-shape fibers, could alter the performance of geopolymer concrete. The source of aluminosilicate (fly ash) used in the production of geopolymer concrete may lead to a different result. This study focuses on the comparison between Malaysian fly ash geopolymer concrete with the addition of hooked steel fibers and geopolymer concrete with the addition of straight-end steel fibers to the physical and mechanical properties. Malaysian fly ash was first characterized by X-ray fluorescence (XRF) to identify the chemical composition. The sample of steel fiber reinforced geopolymer concrete was produced by mixing fly ash, alkali activators, aggregates, and specific amounts of hook or straight steel fibers. The steel fibers addition for both types of fibers are 0%, 0.5%, 1.0%, 1.5%, and 2.0% by volume percentage. The samples were cured at room temperature. The physical properties (slump, density, and water absorption) of reinforced geopolymer concrete were studied. Meanwhile, a mechanical performance which is compressive, as well as the flexural strength was studied. The results show that the pattern in physical properties of geopolymer concrete for both types of fibers addition is almost similar where the slump is decreased with density and water absorption is increased with the increasing amount of fibers addition. However, the addition of hook steel fiber to the geopolymer concrete produced a lower slump than the addition of straight steel fibers. Meanwhile, the addition of hook steel fiber to the geopolymer concrete shows a higher density and water absorption compared to the sample with the addition of straight steel fibers. However, the difference is not significant. Besides, samples with the addition of hook steel fibers give better performance for compressive and flexural strength compared to the samples with the addition of straight steel fibers where the highest is at 1.0% of fibers addition.

Foamcrete is fabricated by combining mortar slurry and constant foam. Owing to the existence of air entrained in its cementitious matrix, foamcrete is tremendously brittle compared to normal-strength concrete. The addition of synthetic and natural plant fibers demonstrates an enhancement to foamcrete’s mechanical performance yet exerts a harmful effect on long-term performance. Depreciation of natural plant fibers and corrosion of synthetic fibers impact the lifespan and durability properties of foamcrete. Hence, this study aims to investigate the mechanical properties and mode of failures of foamcrete reinforced with fiberglass mesh (FM). The parameters assessed were the compression, flexural, and splitting tensile strengths of 1100 kg/m³ density foamcrete confined with various layers of 145 g/m² of FM. The optimal foamcrete mechanical properties enhancement was attained with three-layer jacketing. Notable augmentations of 108% in the compressive strength, 254% in flexural strength, and 349% in splitting tensile strength were achieved in comparison to the control specimens at day 28. The control foamcrete samples under compressive, flexural, and tensile loads encountered brittle failure in comparison to the confined foamcrete. The mode of failure under the tensile load indicates that only a slight crack occurred at the upper side and a perpendicular mark at the lateral section of the foamcrete with one to three layers of FM jacketing. Thus, the jacketing system of foamcrete with FM enhances the behavior and load carrying capacity of foamcrete to the extent of preventing the propagation of cracks.

This study summarised the recent achievement in developing fiber reinforced geopolymer concrete. The factor of replacing Ordinary Portland Cement (OPC) which is due to the emission of carbon dioxide that pollutes the environment globally is well discussed. The introduction towards metakaolin is presented. Besides, the current research trend involved in geopolymer also has been reviewed for the current 20 years to study the interest of researchers over the world by year. Factors that contribute to the frequency of geopolymer research are carried out which are cost, design, and the practicality of the application for geopolymer concrete. Besides, the importance of steel fibers addition to the geopolymer concrete is also well discussed. The fundamental towards metakaolin has been introduced including the source of raw material, which is calcined kaolin, calcined temperature, chemical composition, geopolymerisation process, and other properties. Alkali activators which are mixing solution between sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) have been reviewed. The mechanical properties of fibers reinforced metakaolin-based geopolymer concrete which is compressive and flexural are thoroughly reviewed. The compressive and flexural strength of fiber-reinforced metakaolin geopolymer concrete shows some improvement to the addition of steel fibers. The reviews in this field demonstrate that reinforcement of metakaolin geopolymer concrete by steel fibers shows improvement in mechanical performance.

This paper aims to find out the effect of different weight percentages of geopolymer filler in glass-reinforced epoxy pipe, and which can achieve the best mechanical properties and adhesion between high calcium pozzolanic-based geopolymer matrices. Different weight percentages and molarities of epoxy hardener resin and high calcium pozzolanic-based geopolymer were injected into the glass fiber. By manually winding filaments, composite samples were produced, and they were then allowed to cure at room temperature. To determine how well the geopolymer matrices adhere to the fiber reinforcement, the microstructure of the composites’ surfaces and perpendicular sections were examined. Maximum values of compressive strength and compressive modulus were 94.64 MPa and 2373.58 MPa, respectively, for the sample with a weight percentage of filler loading of 30 wt% for an alkali concentration of 12 M. This is a relatively wide range of geopolymer weight percentage of filler loading from 10 wt% to 40 wt%, at which we can obtain high compressive properties. By referring to microstructural analysis, adhesion, and interaction of the geopolymer matrix to glass fiber, it shows that the filler is well-dispersed and embedded at the fiber glass, and it was difficult to determine the differences within the range of optimal geopolymer filler content. By determining the optimum weight percent of 30 wt% of geopolymer filler and microstructural analysis, the maximum parameter has been achieved via analysis of high calcium pozzolanic-based geopolymer filler. Fire or elevated temperature represents one of the extreme ambient conditions that any structure may be exposed to during its service life. The heat resistance or thermal analysis between glass-reinforced epoxy (GRE) pipe and glass-reinforced epoxy pipe filled with high calcium pozzolanic-based geopolymer filler was studied by investigating burning tests on the samples, which shows that the addition of high calcium pozzolanic-based geopolymer filler results in a significant reduction of the melted epoxy.

This research analyzes the effect of sodium hydroxide (NaOH) solution concentration ranging from 8M to 12M as alkaline activator on the properties of geopolymer paste. Alkaline activator is essentially a mixture of sodium hydroxide and sodium silicate solution. In this research, the main component used was raw kaolin. In order to produce kaolin based geopolymer paste, the alkaline activator solution was prepared with 0.24:1.00 ratio of Na₂SiO₃/NaOH and this alkaline activator solution was prepared for 24 hours prior before used in another process. The solid-to-liquid ratio which is kaolin-to alkaline activator solution ratio was 0.80:1.00. The mixture of kaolin based geopolymer paste were placed in cube moulds with a size of 50x50x50 mm, and left for 24 hours until it hardened. Then, the samples were cured at 80? in the oven for 24 hours. The samples of kaolin based geopolymer paste were tested based on compressive strength, morphology analysis, water absorption and porosity after 28 days. In this project, 8M concentration of NaOH solution was the best concentration in order to study the synthesis of kaolin based geopolymer paste as the sample had the highest amount of compressive strength with 0.992 MPa and had the lowest water absorption and porosity with 1.246% and 24.08% respectively. Scanning Electron Microscope (SEM) was used to observe the morphological structure of the kaolin based geopolymer paste. The sample with 8M concentration of NaOH solution shows that least amount of unreacted particles. The structure of kaolin based geopolymer paste was more dense at 8M concentration as the size of pore decreases. The kaolin based geopolymer paste is suitable for use in the construction building industry as a finishing product such as coating.

This study assessed the morphology and chemical composition of coir coconut husk carbon fiber, as well as the impact of fiber diameters on the physical and mechanical properties of polylactic acid composites. Researchers are studying polylactide acid, a biodegradable material. This eco-friendly material’s excellent features, generated from sustainable and renewable sources, have drawn many people. Malaysia’s high coconut fiber output made coir husk a popular commodity. Coconut fibers are lignin, cellulose, and hemicellulose. Alkaline treatment eliminates hemicellulose, oil, wax, and other contaminants from coir fibers and removes lignin. Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy were used to examine the treated coconut fibers’ chemical modification analysis and morphology. Coconut coir husk was carbonized to produce carbon fiber using a furnace operated at 300°C for 2 hours. Fiber and polylactic acid were mixed in different fiber sizes (0, 53 μm, 75 μm, and 212 μm) via extrusion and injection processing techniques. The results showed that the alkali treatment reduced the hydroxyl (-OH) group and separated the area from the carbonyl (C=O) group of coconut coir husk, which changed the filler’s hydrophilicity. The fiber size of 212 μm was discovered to have the highest tensile and flexural strength values. According to testing, the modified material structure had a better surface fill-matrix bond. Thus, generalized fiber sizing and characterization methods were developed. Regardless of the matrix, this method can characterize natural fiber strength and interfacial shear strength of varied diameters and solid contents.