Plastic electronic waste (E-waste) is constantly growing around the world owing to the rapid increase in industrialization, urbanization, and population. The current annual production rate of E-waste is 3–4% in the world and is expected to increase to 55 million tons per year by 2025. To reduce the detrimental impact on the environment and save natural resources, one of the best solutions is to incorporate waste plastic in the construction industry to produce green concrete. This study examines the use of manufactured plastic coarse aggregate (PCA) obtained from E-waste as a partial replacement of natural coarse aggregate (NCA) in concrete. Six types of concrete mix with 10%, 20%, 30%, 40%, and 50% substitution of NCA (by volume) with PCA are prepared and tested. This study investigates the effect of manufactured PCA on the fresh and hardened characteristics of concrete. The properties of recycled plastic aggregate concrete (RPAC) studied include workability, fresh density, dry density, compressive strength (CS), splitting tensile strength (STS), flexural strength (FS), sorptivity coefficient, abrasion resistance, ultrasonic pulse velocity (UPV), and alternate wetting and drying (W–D). The results indicate that the CS, STS, and FS of RPAC declined in the range of 9.9–52.7%, 7.8–47.5%, and 11–39.4%, respectively, for substitution ratios of 10–50%. However, the results also indicate that the incorporation of PCA (10–50%) improved the workability and durability characteristics of concrete. A significant decrement in the sorptivity coefficient, abrasion loss, and UPV value was observed with an increasing amount of PCA. Furthermore, RPAC containing different percentages of PCA revealed better results against alternate W–D cycles with respect to ordinary concrete.

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.

Nano graphite platelets (NGPs) belong to the carbon family and have a huge impact on the construction industry. NGPs are used as multi-functional fillers and have the potential to develop reinforcing within cementitious composites. In this paper, NGPs were incorporated in cementitious composites to investigate the effects of NGPs on the fresh, mechanical, durability, and microstructural properties of concrete. Five mixes were prepared with intrusion of NGPs (0%, 0.5%, 1.5%, 3%, and 5% by weight of cement). The properties studied involved workability, air content, hardened density, compressive strength, tensile strength, flexural strength, sorptivity, ultrasonic pulse velocity (UPV), water absorption, and external sulfate attack. The workability and percent air content decrease by 22.5% and 33.8%, respectively, for concrete with 5% NGPs compared to the control mix. The specimens containing 5% of NGPs revealed the hardened density, compressive, tensile, and flexural strength to increase by 11.4%, 38.5%, 31.6%, and 44.34%, respectively, compared to the control mix. The results revealed that the incorporation of 5%NGPs in cementitious composites reduces the sorptivity and water absorption by 32.2% and 73.9%, respectively, whereas, it increases the UPV value by 7.5% compared to the control mix. Furthermore, the incorporation of NGPs provided better resistance against external sulfate attacks. SEM–EDX spectroscopy was carried out to investigate its microstructural analysis.

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.