Construction recycled material is crucial for protecting natural resources and promoting sustainable human development in a rapidly industrializing world. Many administrations worldwide accepted that it is beneficial to use demolition waste in the concrete building industry to reduce manufacturing costs and minimize the use of virgin aggregates. However, control measures should be done as their mechanical properties are poorer than traditional aggregates. To overcome this problem, pozzolanic materials like bone chine can be incorporated, providing extra CSH gel, which improves mechanical strength. Therefore, this research is aimed at producing eco-friendly concrete, which can be used for medium-grade strength, using recycled construction waste (RCA) as coarse and bone china fine aggregate (BCA) as fine aggregate. Workability, density, compressive, split tensile, and flexural strength are used to compare the fresh and hardened properties of the concrete. Experimental and statistical research is employed in the current study to evaluate the impact of RCA and BCA on the performance of concrete. To simulate all measurable responses, including workability, density, compressive, flexural, and split strength, RSM (response surface methodology) was utilized. The CCD (Central Composite Design) approach in RSM was used to create and analyze mixes in an experiment. Based on the experiment’s results, mathematical models were designed and assessed using the analysis of variance test (ANOVA). The analysis of variance results demonstrated the statistical significance of each constructed model. Three-dimensional response surface plots created using established regression models were used to investigate the interaction between the respective variables and to optimize the mixing ratio. The results indicate that the optimum utilization of RCA is up to 40% and BCA up to 60% as coarse and fine aggregate replacement in concrete, respectively, which not only helps to reduce costs but also offers sustainability. Finally, it was concluded that the generated models might be employed by obtaining the maximum tested features of concrete to assure a quick mix design approach. To conduct the microstructure study, thin section techniques were used to observe a strong aggregate-matrix interaction.

In this rapidly industrializing world, recycling materials for construction is crucial for protecting natural resources and promoting sustainable human growth. It should be carefully considered because using the waste in the structural concrete is cost-effective but it is also constrained due to its declining qualities. Bone China waste (BCW) possesses pozzolanic properties and it was occasionally used in concrete by a few researchers. Therefore, in the current investigation, the workability, compressive, split tensile, and flexure strengths of the fresh and hardened characteristics are first determined. 0%, 20%, 40%, 60%, 80%, and 100 percent of (BCW) were utilized to replace natural fine aggregate (sand). The experiment’s findings demonstrate that every percentage of BCW replacement yields the desired characteristic strength, a mix with 60% BCW yielding the highest strength value. Furthermore, it was discovered that utilizing fine bone China instead of conventional fine aggregate in concrete increased the compressive, split tensile, and flexure strength. Through traditional laboratory experiments, a valid criterion for choosing an ideal mix combination of BCW as fine aggregate in concrete is quite laborious and time-consuming. As a result, the statistical models were presented based on the laboratory-tested compressive strength data for concrete including varying amounts of bone China waste as fine aggregate, which show resilience and normality when assessed using fundamental statistical techniques. Finally, a good agreement was found between the created models and the experimental results as well as with proven existing models. These models can forecast the compressive, flexural, and split tensile strengths of concrete when combined with bone China fine aggregates or any other type of fine waste. With this framework, one may examine the same factors as the study and make sure that concrete has the maximum strength and sustainability. An improved microstructure of the concrete was observed which exhibits fewer porosity and cracks when fine BCW was used in place of sand.

E-waste is a general term for damaged, surplus, or excess electrical and electronic equipment. Due to quick technological advancement and inexpensive beginning costs, there is a rapidly expanding global surplus of e-waste. If not managed appropriately, the many sorts of compounds and chemicals included in e-waste can seriously harm both human health and the environment. Large volumes of e-waste may be recycled in the concrete sector, solving both the disposal and reuse issues. The most practical application of e-waste is thus thought to be recycling and reuse in the geopolymer concrete (GPC) industry. The experimental study is carried out to enhance the mechanical properties of the GPC (M30 Grade) with varies percentage e-waste replacement for coarse aggregates by casting cubes, cylinders, and beams. Also, an empirical regression-based model is also formulated for the evaluation of the strength of GPC at varying e-waste coarse aggregate (EWCA) percentages.