Nowadays, Environmental concern towards plastic waste rises because of its low degradability and creating problems like chunking sewer lines, drainages, waterways, filling landfills, health problems, etc. The best approach is recycling and reuses plastic waste. Increase in the production of plastic day by day but, very little was recycled. On the other hand, huge demand for concrete in the construction industry. Utilization of recycled plastic waste in the production of sustainable concrete by partial replacement of fine aggregate. This study has been investigated the utilization of two types of recycled plastic waste Polyethylene Terephthalate (PET) and Polypropylene (PP) as fine aggregate in concrete. M30 grade of concrete has been used by partial replacement of fine aggregate (River Sand) with recycled plastic waste in the percentage of 5, 10, 15, 20, and 25. The workability and compressive strength results are checked to find the acceptable percentage of incorporation of PET and PP in concrete. From the results, it is observed that the workability is decreased as the percentage of recycled plastic waste is increased. The Optimum Percentage of replacement of PET is 10%. PP has shown a marginal reduction in compressive strength for 5% replacement.

In the current study, the M25 grade concrete mixes are admixed with various locally available organic and non-organic corrosion inhibitors such as Calcium Nitrite, Sodium Nitrite, Hexamine and Di-ethanolamine to understand the influence of these organic and non-organic corrosion inhibitors on the strength and corrosion resistance properties of concrete. The percentage dosage of admixed inhibitors vary from 1 to 5% by the weight of cement. For M25 grade concrete the optimum percentages of corrosion inhibitor admixture was found to be 4% for Calcium Nitrite, 3% for Sodium Nitrite, 2% for Hexamine and 3% for Di-ethanolamine. Calcium Nitrite corrosion inhibitor admixture imparts increased compressive, split- tensile and flexural strength than other corrosion inhibitors at 28 days. All the corrosion inhibitors used in the study have enhanced the compressive strength, split tensile strength, and flexural strength of concrete. The initial gain of early strength decreased due to anodic process of inhibitors. Measured electrical resistivity and half-cell potential values of all corrosion inhibitors admixed M25 grade concrete mixes directs that calcium nitrate and Di-ethanolamine have shown high electrical resistance indicating their superior corrosion inhibition ability than sodium nitrite and hexamine. Accelerated corrosion test on reinforced concrete beams admixed with corrosion inhibitors confirmed that possible inception of corrosion in calcium nitrate admixed reinforced concrete beams is very low when compared to other corrosion inhibitors used for the study.

Curing of concrete is maintaining satisfactory moisture content in concrete during its early stages in order to develop the desired properties. « However good curing is not always practical in many cases, therefore the need to develop self-curing agents attracted several researchers ». « The concept of several self-curing agents is to reduce water evaporation from concrete and hence increase the water retention capacity of concrete compared to conventional concrete, the use of self-curing agent is very important from the point view that water resources are getting valuable every day ». This project summarizes various aspects of self-curing of concrete which can be of valuable assistance in adopting good construction practices at site. M25 grade concrete cube specimens prepared based on the standards and availability of materials without and with 30% of flyash and quarry dust replaced as cement and fine aggregate and cubes cured by covering them with a external self-curing compound BONDIT CURE WB, air dried and normal water. These specimens are then tested after 7,14 and 28 days to obtain the compressive strength in three different conditions. The compressive strength of concrete cubes is calculated and compressive strength of self-curing concrete is compared with the different conditions. At the end of curing period of 7,14 and 28 days the amount of water retained in self cured concrete cubes is calculated and compared with the air dried cubes. Water absorption test is conducted on air dried concrete and self cured concrete cubes and the amount of water is absorbed is calculate and compared.

Polyethylene Terephthalate (PET) and Polypropylene (PP) is mostly used materials for making items like water bottles, food containers and many other plastic products in all fields of life. Due to the scarcity of natural aggregates for making concrete, it is required to go for alternative material, this type of plastic is one of the materials for replacement of fine aggregate in concrete. An objective of this paper is to study the feasibility of this recycled PET and PP plastic waste to be used as a building material in manufacturing of concrete which is replaced in fine aggregate. Polyethylene Terephthalate and Polypropylene is used in various percentages like 5%, 10%, 15% and also various tests like workability and compressive strength, Sorptivity, water absorption, acid attack and sulphate attack tests are conducted. From the results the PP shows good workability but low compressive strength than PET. From the durability point of view, the concrete made with PET and PP have given better results compared to conventional concrete of M30 grade. In PET and PP concrete, PET resists the acid, sulphate and water over the long period much better than the PP. So, PET can be replaced up to 10% in fine aggregate, whereas PP is allowed up to 5% replacement of fine aggregate.