Elsafi Mohamed Adam Elbashiry

One of the biggest problems responsible of the nonrenewable resources depletion and environmental issues is the construction industries, which generates large amounts of mineral waste and harmful emitted gases. Therefore, these problems generated the necessity to search for alternative natural building materials based on renewable resources. To study the mechanical characteristics and microstructural behavior of the concrete reinforced by raw wheat straw basalt fiber composite (RWSBFc), and treated rice straw basalt fiber composite (TRSBFc), a number of experimental tests were carried out with different composites ratios. Concrete compressive strength, splitting tensile strength, and flexural strength tests were considered as main parameters. The results showed that the RWSBFC has a positive effect on concrete flexural strength by increasing of 12.58%, compared with control samples. Also, it showed good enhancement in concrete flexibility and ductility. In contrast, both RWSBFc and TRSBFc showed uneven deterioration in concrete compressive strength and splitting tensile strength. To avoid the deterioration in compressive strengths of the various composites types, some improvement methods such as processors for the used straw, and adding some additives were recommended.

This novel study on cement paste material was conducted with the aim of keeping up with the rapid development of urban construction and contributing to the continuous improvement of building materials to overcome environmental issues. In this study, several kinds of industrial waste were used to enhance the properties of cement paste for application in a marine environment with a tropical climate, such as in Vietnam. This study focuses on evaluating the properties of cement paste containing cement replacement combining 0–30% fly ash, 0–10% silica fume, and plasticizer accounting for 0.3% and 0.4% of the binder by mass. Water demand, chloride ion and sulfate ion permeability, and microstructural properties of the cement paste were determined by thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscope (SEM) and they were investigated after 28 and 56 days. The test results show that an optimum mixture could be obtained with the use of 20% fly ash, 10% silica fume (replacing Portland cement), and 0.4% plasticizer. The application of such materials to sea dikes affected by a tropical climate (characterized by heat, humidity, salty seawater, many big storms, large waves, and strong tides) was investigated for four years on the Vietnamese coast. The test results indicate that fly ash and silica fume can improve the corrosion and abrasion resistance of concrete in coastal areas with a tropical climate, such as in Vietnam.