Disposal of plastic wastes causes negative impacts including degradation of land and ocean and climate change. Reusing plastic wastes in concrete is one of the effective methods of reducing plastic disposal. Polyethylene terephthalate (PET) is one of the most abundantly available plastic wastes as it is commonly used for plastic bottles and food containers. This paper investigates the effects of treating PET wastes using hydrogen peroxide solution (H₂O₂) and calcium hypochlorite solution (Ca(ClO)₂) before incorporating in concrete as coarse aggregate replacements. The physical and mechanical properties of concrete were analyzed for three different percentages, namely, 10%, 20%, and 30%, replacement of natural aggregates with plastic aggregates. For all percentage of replacements, it was found that chemically treated plastic aggregates have no effects on the fresh density, but the slump decreased due to roughened surface of treated plastic aggregates. Chemical treatment improved the bond strength between cementitious matrix and plastic aggregates and reduced the gap at the interfacial transition zone (ITZ). These phenomena contributed to the improvement the compressive strength and lower the permeability and porosity.

Urban sprawl driven by urbanisation has contributed to a sharp rise in privately owned vehicles and competition for restricted resource space. The utilisation of private vehicles has increased, particularly in developing countries, and this phenomenon leads to many negative externalities, including traffic congestion and emissions. To encourage the use of sustainable modes such as public transport, it is essential for policymakers and transport authorities to carefully examine the determinants influencing public transport usage and apply successful policies and procedures. This review offers a valuable understanding of the contemporary knowledge regarding the determinants influencing bus transport usage. It systematically reviews 104 papers published since 2000 on service quality, satisfaction, and attitudes towards bus transport. The review shows that safety, security, comfort, reliability and accessibility are the most substantial determinants shaping users' views on service quality and satisfaction. This is particularly evident in situations like waiting at the bus stop, being on board the bus, and specific instances while walking to their destination. The results indicate that challenges with first-mile and last-mile connectivity are apparent, and further exploration in the context of developing countries is needed to understand these challenges, necessitating further investigation. It also demonstrates instrumental aspects such as convenience and social-symbolic aspects such as social standing, influencing attitudes towards public transport usage. It concludes by suggesting potential paths for future research and discusses the impacts of the results on policy decisions.

Using waste rubber tires for concrete production will reduce the demand for natural aggregate and help to reduce environmental pollution. The main challenge of using waste rubber tires in concrete is the deterioration of mechanical properties, due to poor bonding between rubber and cement matrix. This research aims to evaluate the mechanical and thermal properties of rubberised concrete produced by using different proportions of rubber powder and silica fume. Ordinary Portland cement was partially replaced with silica fume by amounts of 5%, 10%, 15% and 20%, while sand was replaced by 10%, 20% and 30% with waste rubber powder. Tests were carried out in order to determine workability, density, compressive strength, splitting tensile strength, elastic modulus, thermal properties, water absorption and shrinkage of rubberised concrete. The compressive strength and splitting tensile strength of concrete produced using waste rubber powder were reduced by 10–52% and 9–57%, respectively. However, the reduction in modulus of elasticity was 2–36%, less severe than compressive and splitting tensile strengths. An optimum silica fume content of 15% was observed based on the results of mechanical properties. The average shrinkage of concrete containing 15% silica fume increased from −0.051% to −0.085% at 28 days, as the content of waste rubber powder increased from 10% to 30%. While the thermal conductivity of rubberised concrete was reduced by 9–35% compared to the control sample. Linear equations were found to correlate the density, splitting tensile strength, modulus of elasticity and thermal conductivity of concrete with silica fume and waste rubber powder.