Using different types of aggregates including waste concrete in the production of geopolymer mortars

Abstract

In developed and developing countries, the need for industrial and residential buildings is constantly increasing. The old buildings are either demolished or replaced by new buildings in order to maintain environmental awareness and due to limited usage areas. In this construction process, traditional Portland cement is used and also a serious solid waste problem arises due to the demolished buildings. Because of using Portland cement, a significant amount of greenhouse gas production is generated, as well as high levels of environmental pollution due to the accumulation of concrete solid wastes. New laws have been enacted in many countries to reduce greenhouse gas emissions due to Portland cement and for solid waste management, and even the establishment of recycling facilities for waste concrete has been encouraged. The reduction of greenhouse gas emissions and recycling of construction wastes have gained great importance both because of the protection of the natural environment and its contribution to the economy.In this study, more environmentally friendly geopolymer additives were used instead of traditional Portland cement for the recycling of construction waste, as well as geopolymer mortars were produced with different types of aggregates. The 0.4% basalt fiber additive series of the obtained samples were similarly produced. The geopolymer samples produced by using different aggregate types including the waste concrete aggregate were compared in terms of 28 days compressive strengths, ultrasound velocities, unit weight, voids ratio and water absorption results.