ترکیب بتن سبز با استفاده از ضایعات جامد و نانوذرات به عنوان جایگزین – بررسی Green Concrete mix using solid waste and nanoparticles as alternatives – A review

1. Introduction The economy of any country grows based on the infrastructure available. Infrastructure covers roads, bridges, buildings, warehouses, airports, harbors, container terminals etc. As the demand for infrastructure grows, so does the need for concrete, which leads to the demand of more cement. Cement concrete is in great demand in the construction industry and at the same time it is an environmental concern, as it produces hazardous gases in various stages of production. We generally know that any concrete mix has cement, aggregates, sand, water and additives as per design need. With growing demand to control pollution and use waste materials from different industries, this is an attempt to replace standard materials with alternative substitutes. It covers the effects on compressive strength, setting time, cost effectiveness and reduction of pollution levels. Natural resources are not perennial, so we need to find alternatives to replace them without compromising on the quality and effective parameters of the ultimate product. The cement kilns produce hazardous gases and contribute to global warming. Animals are also adversely affected by the pollution caused by cement plants. During transport of cement bags from manufacturing site to end user, it undergoes wear and tear and cement dust flies into the environment. It causes breathing diseases and effects the labor who used to transfer, dump and redistribute the stored cement bags. Solid waste management is a major concern due to increase of quantity of waste materials and industrial by-products. This is increasing the land filling problems and recycling cost of waste materials. Utilization of these materials as Green Concrete is the only option to reduce the disposal concern. The Green Concrete is made from the eco-friendly waste materials and ushers in a revolution in the concrete industries by its technology. The waste products can be reused directly as a partial substitute of cement and save the energy consumption during the production of cement. Some waste materials are having pozzolans properties. Pozzolans is a material rich in silica and alumina which itself possess little or no cementing property, but in the presence of water, it chemically reacts with calcium hydroxide at ordinary temperature to form the cementitious properties [1].