The safe disposal of an enormous amount of waste glass (WG) in several countries has become a severe environmental issue. In contrast, concrete production consumes a large amount of natural resources and contributes to environmental greenhouse gas emissions. It is widely known that many kinds of waste may be utilized rather than raw materials in the field of construction materials. However, for the wide use of waste in building construction, it is necessary to ensure that the characteristics of the resulting building materials are appropriate. Recycled glass waste is one of the most attractive waste materials that can be used to create sustainable concrete compounds. Therefore, researchers focus on the production of concrete and cement mortar by utilizing waste glass as an aggregate or as a pozzolanic material. In this article, the literature discussing the use of recycled glass waste in concrete as a partial or complete replacement for aggregates has been reviewed by focusing on the effect of recycled glass waste on the fresh and mechanical properties of concrete.

Geopolymer (GP) concrete is a novel construction material that can be used in place of traditional Portland cement (PC) concrete to reduce greenhouse gas emissions and effectively manage industrial waste. Fly ash (FA) has long been utilized as a key constituent in GPs, and GP technology provides an environmentally benign alternative to FA utilization. As a result, a thorough examination of GP concrete manufactured using FA as a precursor (FA-GP concrete) and employed as a replacement for conventional concrete has become crucial. According to the findings of current investigations, FA-GP concrete has equal or superior mechanical and physical characteristics compared to PC concrete. This article reviews the clean production, mix design, compressive strength (CS), and microstructure (Ms) analyses of the FA-GP concrete to collect and publish the most recent information and data on FA-GP concrete. In addition, this paper shall attempt to develop a comprehensive database based on the previous research study that expounds on the impact of substantial aspects such as physio-chemical characteristics of precursors, mixes, curing, additives, and chemical activation on the CS of FA-GP concrete. The purpose of this work is to give viewers a greater knowledge of the consequences and uses of using FA as a precursor to making effective GP concrete.

The Sultanate of Oman has experienced rapid development over the last thirty years and has constructed environmentally friendly and sustainable infrastructure while it continues to find economical alternative resources to achieve the goals of the Oman 2040 vision. The primary concerns are preserving natural resources and reducing the impact of carbon dioxide (CO₂) emissions on the environment. This review aims to encourage the sustainable use of reclaimed asphalt pavement (RAP) materials in pavement construction and focuses primarily on employing RAP materials in new pavement projects. Currently, new construction projects utilise a significant percentage of demolished asphalt pavement to save costs and natural resources. The key issue that arises when mixing RAP into new asphalt mixtures is the effects on the mixtures’ resistance to permanent disfigurements, such as fatigue cracks, that influence asphalt mixture performance. Numerous studies have assessed the impact of using RAP in asphalt mixtures and found that RAP increases the stiffness of asphalt mixtures, and thus improves rutting resistance at high temperatures. Nevertheless, the findings for thermal and fatigue cracking were found to be contradictory. This review will address the primary concerns regarding the use of RAP in asphalt pavements, and aims to encourage highway agencies and academic researchers in the Gulf countries to develop frameworks for the practical usage of RAP in the construction of sustainable pavement systems.

Sustainable construction is a rapidly growing area of research focused on using industrial waste to replace Portland cement in concrete. This approach not only reduces CO2emissions from cement production but also serves as an effective way to diminish the environmental impact of concrete production. This study aims to investigate the properties of Coal Bottom Ash (CBA) after undergoing two different treatments: flotation and burning. It also evaluates the impact of CBA as a cement replacement in concrete with different replacement percentages (5%, 10%, 15%, and 20%). Chemical analysis of CBA has revealed that it can be classified as a pozzolanic material due to its high content of silicates, aluminates, and iron oxides. The microstructure of CBA showed a porous, angular, and irregular surface with many voids. The findings of this study revealed that the optimum mix was 10% CBA, resulting in a 2% increase in compressive strength compared to the control mix after 56 days of curing. Additionally, the study evaluated the effects of sulfate and chloride on concrete. It was found that the mix with the burning treatment showed an overall increase in strength, while the flotation treatment did not reach the control mix's strength in any of the curing periods. Furthermore, the results demonstrated that CBA has significant potential as a cement replacement material, and the burning treatment showed improvement in concrete's overall properties compared to the raw material in terms of mechanical and chemical properties while reducing greenhouse gas emissions and enhancing the environment. Doi: 10.28991/CEJ-2024-010-04-08 Full Text: PDF

The exposure of concrete to elevated temperatures is known to cause diverse severe damages in concrete composites. Hence, measures to improve the performance of concrete during exposure to fire are continually proposed. The present study investigated the postfire residual strength and morphology of concrete incorporating natural rubber latex exposed to elevated temperature. Four different concrete mixes were considered for the investigation, namely, a control sample made without natural rubber latex, the second sample containing 1% natural rubber latex, the third sample containing 1.5% natural rubber latex, and the fourth sample containing 3% of natural rubber latex. The concrete samples (150 mm cubes and 100 × 200 mm cylinders) were exposed to varying temperatures 300°C, 800°C, and 1000°C, after the curing process. Nondestructive tests using Schmidt rebound hammer and ultrasonic pulse tester were carried out on samples. The compressive strength and split-tensile strength of concrete cubes and cylinders, respectively, were determined. Micrographs and elemental distribution in the sample were studied using the scanning electron microscopy (SEM-EDX) apparatus. It could be seen from the results that the concrete strength properties reduced as the exposure temperature increased. The results also showed that NRL could be sparingly utilized as a concrete admixture, at 1% content. The performance of concrete was not stable at over 300°C when NRL addition was above 1%.

Push‐out‐shear tests were used in this study to analyze lag screw connections in timber‐concrete composite (TCC) slabs based on the embedment depth. The goal of this research is to look into the relationship between shear capacity and embedment depth in TCC, as well as to investigate the embedment strength of the wood. Experiments were carried out at different embedment depths (5.08 cm, 7.0 cm, and 8.9 cm). The prepared samples were examined in order to determine the failure modes and provide an accurate assessment of the influence of embedment depth on TCC slabs. The investigation on the embedment strength of the wood was performed then for the analysis of the crushing of wood fibers, lag screw yielding strength, and maximum load applied at embedment depths of 6.6 cm and 7.0 cm. The results indicate that between 5.08 cm and 7.0 cm, there was an apparent improvement in the relationship between embedment depth (ED) and shear capacity of TCC slabs in terms of the shear strength, while a significant difference was observed between 7.0 cm and 8.9 cm. The study suggests that the ED of the TCC slab should be maintained at around 7.33 times the diameter of the lag screw.