Investigation of the use of rice husk ash and waste ceramic powder in geopolymer concrete

The solution of the storage problem encountered in reducing the increasing of solid waste capacities is either the reuse of the waste or the conversion of it to an alternative source by reducing it from its source. By this way, as a result of the efficient use of resources and energy that cannot renew itself in nature, that influence on the environment which caused by storage can be reduced. Concrete is one of the most widely used building materials in the world, the most widely used of non￾renewable resources, and even has an important place in solid waste storage. Cement, as the major binder in concrete has a significant impact in CO2 emission levels and environmental influences through its production. The usage of waste in these fields can be considered as an alternative in the lightening of the load of landfills or in the production of building materials at the point of environmental adverse effects. In contrast to traditional concrete production, geopolymer materials are a new type of concrete that is known to be less costly for the protection of the environment and can provide advantages for use in a sustainable development. The aim of this study is to investigate the use of blast furnace slag (GGBFS), ceramic powder (CP) and rice husk ash (RHA) from wastes that occupy a significant amount of space in landfills, which have better properties as an alternative component to cement in geopolymer concrete mixtures. For this purpose, GGBFS 0%, 5%, 10% and 15%' RHA with 0%, 10%, 20% and 30% CP was used in the production of geopolymer concrete. mixes were also identified with the Taguchi L16 matrix formed by the preparation of NaOH as 12, 14, 16 and 18 molalites, an important material in geopolymer production. Flow, densities, porosity and water absorption, compressive strength and behavior of mixtures under the influence of elevated temperatures were statistically analyzed. Results indicated that RHA has adverse effect on flow and water absorption capacity, and CP has a positive effect to achieve higher density and improve the prosity of geopolymer concrete. Furthermore, it was determined that strengthup to 70 MPa can be achieved if 2% RHA or 15% CP is used with 14-16 of molality. In term of elevated temperature effects, it was determined that the resistance values of Geopolymer concretes to high temperatures were lower compared to normal concretes, that the use of CP on geopolymer materials would be more effective, and that special precautions should be taken at values exceeding 450 º C.