Tons of waste glass is being produced annually all over the world and this waste is disposed as landfills but as a matter of fact the waste of glass doesn't decompose in the environment. That has created a threat to the environment. So the dissertation work was carried to study the effect of waste glass powder in various concrete grades by partial replacement of cement. Use of milled waste glass in concrete as partial replacement of cement could be an important step toward development of eco-friendly and techno-economical systems. In this study OPC was replaced partially with waste glass powder at 5%, 10%, 15% and 20% by weight of the cement in three different grades of concrete M20, M25 and M30 and tested for Flexural Strength and Split Tensile Strength at 7 th and 28 th days and the results were compared with those of conventional concrete.The results show improvement in the Flexural strength and Split Tensile Strength.

Pumice is a rock particle that was used in this experiment’s concrete, and light weight aggregate is a type of aggregate that is lighter than natural aggregate. The major purpose of the suggested methodology is to use optimization techniques to frame a mathematical model. Structural lightweight concrete is used extensively in the construction sector, particularly in high-rise buildings. Only lightweight aggregates can be used to make it. Pumice is a solid component and a highly porous rock light in nature that can be used as an alternative to coarse aggregate (CA) in concrete and Nano Silica an alternative for cement. This lightweight aggregate, on the other hand, has a higher density than other natural and artificial lightweight aggregates. As a result, the density of concrete made with this lightweight aggregate is relatively high, falling into the semi-lightweight concrete category. According to the latest analysis, to further at the density of an lightweight concrete with high strength, Pumice was partially replaced with a coarse aggregate. In this study, pumice was substituted for CA in percentages of 0%, 20% and 30% by quantity and Nano Silica replaced in 1-3% for different mixes to predict three output parameters such as compressive strength (Mpa), split tensile strength (Mpa), flexural strength (Mpa). The addition of pumice to CA concrete decreases density while also lowering all mechanical properties, according to test results. This is because pumice has a smooth surface texture and has a lower density than CA. On the other hand, lightweight concrete containing more than 20% pumice changes into structural lightweight concrete with excellent strength. Several studies demonstrated an overall gain in strength as well as weight loss. As a result, light-weight concrete is equal to heavy-weight concrete in terms of strength.

This study proposes the use of waste plastics namely high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene ethylene (PPE) as a replacement to natural coarse aggregates in M20 mix concrete. The study was carried out by testing specimens prepared by replacing recycled waste plastic coarse aggregates (RPCA) produced using semi mechanized process and conventional mix for their workability, compressive strength, flexural strength, split tensile strength and behavior of plastic aggregates at high temperature. Three different set of plastic aggregates were produced by using HDPE LDPE PPE plastic wastes respectively. It was observed that concrete mixes with increasing percent of plastic waste aggregates showed decrease in workability. Compressive strength and flexural strength reduced due to weak Interfacial Transition Zone (ITZ) between plastic aggregates and paste. Tensile strength increased by addition of waste plastic aggregates due to its aggregate property. Exposure of concrete specimens to higher temperature behaved positively in strength parameters. Replacement of 10-20% of RPCA can be made without affecting strength and durability parameters.