Researchers have been driven to investigate sustainable alternatives to cement production, such as geopolymers, due to the impact of global warming and climate change resulting from greenhouse gas emissions. Currently, they are exploring different methods and waste materials to enhance the mechanical and physical properties of geopolymer and expand its application range. This review paper offers a thorough analysis of the utilization of various waste materials in geopolymer manufacturing and shows the creative contribution of this research to the development of environmentally friendly cement substitutes. The article covers the properties, durability, and practical applications of geopolymer composites made from various waste binders. It includes a microstructure and chemical analysis. The research findings indicate that geopolymers are an effective cementitious binder substitute for cement in various applications. Additionally, the ecological and carbon footprint analysis highlights the sustainability of geopolymers compared to cement.

Due to its significant deficiencies such as low permeability, low bearing and shear strength, and excessive compressibility, soft soil is one of the most problematic types of soil in civil engineering and soil stabilization can be considered a suitable technique for pavements. This study investigates the use of ground granulated blast slag (GGBS) and cement kiln dust (CKD) as stabilizers for soft soil. Thus, this study involves two optimization stages; in the first stage, GGBS was incorporated into 0%, 3%, 6%, 9%, and 12% by the weight of cement to obtain the optimal percentage, which was 6%. Then, the optimal GGBS was blended with CKD in a binary system at 0%, 25%, 50%, 75%, and 100% by the dry weight of the soil. The testing program used in this paper was Atterberg limits with compaction parameters to investigate the physical properties and unconfined compressive strength (USC) at 7 and 28 days to examine the mechanical characteristics. In addition, the microstructures of the soil specimens were tested at 7 and 28 days using scanning electron microscopy (SEM). The findings reveal that the binary system enhanced the physical and mechanical properties of the soft soil. The optimum binder achieved in this study was 6% (25% GGBS and 75% CKD), which generates an increase in strength of about 3.3 times in 7 days, and of 5.5 times in 28 days in comparison to the untreated soil. The enhancement was attributed to the formation of the hydration products as approved by SEM. Consequently, in the case of soft subgrade soils, this technique can increase the pavement’s bearing capacity and performance.

Asphalt is widely employed in road construction due to its durability and ability to withstand heavy traffic. However, the disposal of waste polymers has emerged as a significant environmental concern. Recently, researchers have used polymer waste to modify asphalt pavements as a new approach. This approach aims to improve pavement performance and address the environmental concerns of polymer waste. Researchers have demonstrated that incorporating polymeric waste into asphalt mixtures can lead to performance improvements in asphalt pavements, particularly in mitigating common distresses including permanent deformation and thermal and fatigue cracking. The current comprehensive review aims to summarize the recent knowledge on the usage of waste polymers in asphalt mixtures, encompassing their impact on performance properties and mixture design. The review also addresses different types of waste polymers, their potential benefits, challenges, and future research directions. By analyzing various studies, this review offers insights into the feasibility, effectiveness, and limitations of incorporating waste polymers into asphalt mixtures. Ultimately, this contributes to the advancement of sustainable and environmentally friendly road construction practices.

Waste ceramic is produced from different sources and, if not reused, is often disposed of in landfills, contributing to the pressure on landfill capacity and potentially releasing toxins into the surrounding environment as ceramics break down over time. The waste can easily be crushed to the required sizes, which has interested many researchers. It has been used as a replacement for concrete constituents, including cement and aggregates. This offers a promising avenue for reducing the environmental impact and promoting sustainable construction practices by reducing the amount of energy consumed and resources required for concrete production, as well as the amount of waste being sent to landfills. This paper aims to provide a review of the use of waste ceramic in concrete. In essence, the paper is divided into several sections. The first section highlights the current environmental issues associated with concrete production and waste disposal. The second section deals with ceramics, its raw materials, production steps, and the different types of waste ceramic used in concrete. A literature review of the use of waste ceramic in concrete was included in the third section. The study reports different research on the use of waste ceramic and its impacts on the mechanical and durability properties of concrete.

The intrinsic ability of asphalt pavement to undergo self-healing is not sufficient enough to effectively repair fractures resulting from a range of variables, including traffic load, asphalt aging and weather conditions. Consequently, the field of self-healing technology is focused on advancing crack repair techniques by employing microwave and induction heating and encapsulation amongst other healing procedures. These approaches make use of a range of additives, including waste materials and polymers, to facilitate the healing process. The present paper provides an in-depth review of self-healing technologies used for asphalt pavements, this including their conceptualization, development, application and the methods used to evaluate its performance. The self-healing capacity of materials can be influenced by various parameters including humidity, molecular diffusion, induction conditions, temperature and time. As such, treatments have the potential to enhance self-healing capacity, but with varying degrees of success depending on the specific evaluation indicator and healing situation. By examining international research, this review will also draw attention to the global relevance of the applicability of asphalt self-healing techniques used to enhance the durability and sustainability of transportation infrastructures worldwide. This paper therefore, serves as a valuable resource for researchers, practitioners and policymakers engaged in the pursuit of innovative solutions for resilient and cost-effective pavement systems on an international scale. This review also proposes prospective pathways for further study that will serve as a basis for future development of the industry.

The asphalt industry has long been challenged with finding sustainable solutions to enhance the performance of asphalt mixtures while mitigating their environmental impact. One promising avenue is the incorporation of waste filler materials into asphalt mixtures. This review explores the feasibility and effectiveness of utilizing waste filler in asphalt mixtures, focusing on its effects on the mechanical characteristics, durability, and sustainability of asphalt pavements. Various waste filler materials, such as rice husk ash, fly ash, and construction and demolition wastes, have been examined in terms of their potential as substitutes for traditional filler materials such as limestone and mineral powders. This review synthesizes literature to assess the impact of waste fillers on the performance of asphalt mixtures, including rutting resistance, fatigue behavior, moisture susceptibility, and aging characteristics. This work begins by examining the interaction of the asphalt fillers to provide clarification. The usage of various waste fillers is then examined. With fewer harmful environmental consequences than traditional cement manufacturing has, waste filler materials improve the strength and durability of asphalt mixtures. This research underscores the promising future of waste filler materials as environmentally friendly and innovative materials. To fully capitalize on their benefits, further research, standardization, and widespread use of waste filler-based products are necessary.