The exponential growth in industrialization, urbanization, and population has subsequently increased the accumulation of different wastes to hazardous levels. Among these, electronic waste (E-waste) poses a serious threat to the environment with its production rising due to technological advancements worldwide. Therefore, recycling E-waste as an alternate aggregate replacement material in the construction industry can be advantageous in managing this waste stream. This study aims to present a comprehensive insight into the integrated applications of E-waste concrete composite materials in the construction industry including applications to increase the environmental sustainability of concrete structures. This review starts with an illustration of the environmental issues caused by E-waste, elucidates its sources and prevailing recycling practices, and investigates its utility as supplementary cementitious materials. This discussion is further followed by an analysis on recycled E-waste plastic aggregate concrete (RPAC) composites, covering their fresh properties, mechanical properties, thermal properties, durability, and serviceability performance. Besides, this paper also explores the evaluation of the utilization of E-waste fibers (E-fiber) as well as the application of E-waste glass (E-glass) from cathode ray tubes (CRT) in concrete. Based on the detailed review, the positive aspects and the restrictions associated with utilizing E-waste in construction have been highlighted.

This study investigates the effect of ground granulated blast furnace slag (GGBFS) and metakaolin (MK) on the strength and ductility of magnesium oxychloride cement (MOC) based hybrid basalt and polyethylene fibre reinforced cementitious composite (FRMOC). MOC was chosen as the matrix due to its unique properties and environment friendliness as a green cement. MK and GGBFS were selected as primary additives to reinforce the MOC matrix owing to their outstanding performance in cementitious composites, coupled with their widespread availability and sustainable characteristics. The influence of GGBFS and MK on physical and mechanical properties of FRMOC was studied in this paper through extensive physical and mechanical testing and microscopic analysis. It was found that the hardened density of FRMOC was not significantly affected by these additives, and it ranged from 1909.3 to 1976.0 kg/m³, retaining its lightweight characteristics. Compressive strength of specimens cured for one day reached approximately 69.1–84.0% of that for specimens cured for 28 days, indicating the high early strength characteristics of the material. All FRMOC specimens exhibited tensile strain hardening properties, with tensile strength and strain capacity ranging from 6.74 to 8.58 MPa and 1.14 to 2.22%, respectively. The mix containing 30% GGBFS, 0.75% basalt fibre, and 1.25% polyethylene fibre was identified as the optimum MOC mix with enhanced compressive strength (73.9 MPa), tensile strength (8.52 MPa), and strain capacity (2.22%). Microscopic analysis further revealed that the addition of GGBFS-MK blends did not alter the primary phase composition of hydration products but essentially promoted the formation of phase 5, demonstrating their effectiveness in enhancing the performance of FRMOC.

Magnesium oxychloride cement (MOC), an alternative to ordinary Portland cement (OPC), has attracted increasing research interest for its excellent mechanical properties and its green and sustainable attributes. The poor water resistance of MOC limited its usage mainly to indoor applications; nevertheless, recent advances in water-resistant MOC have expanded the material’s potential applications from indoor to outdoor. This review aims to showcase recent advances in MOC, including water-resistant MOC and ductile fiber-reinforced MOC (FRMOC), exploring their potential applications including in sustainable construction for future generations. The mechanism under different curing procedures such as normal and CO₂ curing and the effect of different inorganic and organic additives on the water resistance of MOC composites are discussed. In particular, the review highlights the recent developments in achieving over 100% strength retention under water at 28 days as well as advancements in FRMOC, where tensile strength has surpassed 10 MPa with a remarkable strain capacity ranging from 4–8%. This paper also sheds light on the potential applications of MOC as a fire-resistant coating material, green-wood-MOC composite building material, and in reducing solid waste industrial byproduct accumulations. Finally, this study suggests future research directions to enhance the practical application of MOC.

Magnesium oxychloride cement (MOC) is often recognized as an eco-friendly cement and has found widespread application in various sectors. However, research on its resistance against elevated temperatures including fire is very limited. This paper thoroughly investigated the mechanical performance of fibre reinforced MOC-based cementitious composite (FRMOCC) at ambient and elevated temperatures. A recently developed water-resistant MOC was used as the base matrix which was further reinforced using hybrid basalt and polypropylene fibres at various proportions, and a systematic study on the effect of fibre dosage on compressive and tensile strength of FRMOCC was conducted. The specimens were exposed to elevated temperatures ranging from 200 to 800 °C; mechanical performance and phase composition from a microscale study were analysed. The findings revealed that compressive strength, with the increase in temperature, substantially decreased, with values of 30–87% at 400 °C and over 95% at 800 °C. Specimens with 1.5% basalt and 0.5% PP fibre showed the least reduction possibly due to the vacant channels created as a result of the melting effect of PP fibres. Tensile strength was also completely lost at 600 °C and the specimens suffered substantial mass loss exceeding 30% at this temperature, indicating significant matrix decomposition. Additional analysis using X-ray diffraction (XRD) and scanning electron microscope (SEM) revealed the decomposition stages of the matrix and highlighted the instability of the main hydration phases of FRMOCC at elevated temperatures.