India generates 759.02 million metric tons of coal ash annually. Part of that quantity is successfully utilized, and the remaining portion of the ash is discarded into a landfill. There also is a need to address pollution. Cement industries are responsible for 7% of global warming. Cement has been replaced entirely by thermal power plant waste, and bottom ash is used as a binder to overcome those issues. A few researchers have carried out strength characterization, but an extensive study needs to be carried out under different environmental exposures. Therefore, the present study investigated macro and micro properties of bottom ash geopolymer concrete (BAGPC) subjected to aggressive ecological exposure conditions such as acid, salt, and sulfate attack. Sodium silicate (Na₂SiO₃) and sodium hydroxide (NaOH) of eight molarities were used as activators for the bottom ash geopolymer concrete (BAGPC) binder. Further bonding between steel and conventional concrete BAGPC mixes was investigated. The durability of conventional concrete (CC) was taken as the control mix to compare the durability of the optimized mix (B4) of bottom ash geopolymer. The test samples were cured for 28 days under ambient temperature and tested for the effect of MgSO₄, NaCl, and HCl. The strength loss and weight loss of the BAGPC B4 mix after 7, 28, 56, 90, and 180 days under aggressive conditions showed better performance than CC. It has been observed that geopolymer concrete has good bonding in nature, and the bond strength results indicate excellent bonding between steel and concrete. Microstructure studies revealed that the BAGPC B4 mix had a strong microstructure and not as much of a porous structure. It is concluded that BAGPC has potential value in the construction industry based on all aspects of the experiment.

The impact of integrating Nano Silica (NS) on mechanical characteristics, resistance towards impact, and chloride penetration on concrete having Fly Ash (FA) are investigated in this research. The NS particles are subsequently mixed into concrete at one, two, three, four, and five percent of the binder’s mass, respectively. The performance of the specimens under an impact load is assessed by utilizing the drop weight impact technique, frequency on strikes, and impact force variation has been used to evaluate the specimen's impact resistance. The concrete's ability to withstand damage from chloride penetration was evaluated by determining the chloride diffusion coefficient of the samples. The test findings demonstrated that adding NS to concrete may significantly increase its mechanical characteristics as well as chloride penetration resistance. The optimum amount of NS substitution in concrete is two to three percent and it is discovered that if the proportion of NS is too large, the benefits of incorporating NS into the characteristics of the concrete are diminished, and might even have a detrimental effect on the resistance towards impact and durability of the concrete. Moreover, the experimental compressive strength and split tensile is compared with existing gene expression programming model.

This study examines the effects of using crushed Printed Circuit Board (PCB) (also known as E-waste aggregate) in concrete as a partial substitute for regular coarse aggregate (NCA). M25 grade concrete was utilized. After substituting 0%, 10%, and 15% of the natural coarse aggregates with E-waste aggregate, three combinations were still complete. Verified examples continue to focus on strength attributes, after which long-lasting characteristics such as aquatic concentration, thermal expansion, and abrasion encounter tests were carried out. Test results proved that when the replacement percentage of Electronic waste aggregate was higher significant reduction in strength properties was noticed. It is container remains credited to the reality that incorporation of E-waste aggregate slows down the hydration process that would lead to a significant loss in strength. However, it was observed that mix made with 10% and 15% E-waste aggregate shows better resistance against durability properties than control mix concrete. It was also observed that utmost care should be taken for maintaining proper workability and removal of toxic substances in E-waste aggregate for better forte and toughness properties.