Examination of the compressive resistance properties of geopolymer concretes produced using fly ash and blast furnace slag as a result of storing them open in the laboratory

According to the researches, geopolymer concrete (cementless) is generally known as cementless concrete. Cement production in Turkey is known as the fifth largest cement producer in the world and the largest in Europe, with an annual production of 107.5 million tons of cement and 68.5 million tons of clinker in 2018. Clinker, the main component of cement, is obtained by burning. They are raw materials containing calcium, silicon alumina, iron oxide and small amounts of various substances at high temperature (1400 C). Cement is a component with good adhesion properties, widely used all over the world. Cement production has increased by 7% worldwide in recent years, while in Turkey it increased by 16.5%. Cement is the most widely used binder in the construction industry today in the production of concrete and mortar. The cement industry is responsible for about seven percent of anthropogenic carbon dioxide emissions worldwide. It is generally accepted that 1 ton of clinker produces 1 ton of CO2 emissions if fossil fuels are used in cement production and no solution method is used. (Erdoğan, 2014). The high carbon dioxide emissions in cement production, which adversely affect human health and environmental pollution, have attracted the attention of many environmental communities. The rising environmental pollution in the world, especially the fact that Turkish cement factories produce more cement than the domestic market consumes and high CO2 emissions have increased environmental awareness. As a result, many researchers have started to use waste materials as an alternative to cement and to conduct research on waste material recycling. The geopolymer that emerged as a result of the researches that can be obtained by recycling residual materials with pozzolanic properties (silicidum, volatile particles, blast furnace slag, etc.) is x concrete. Considering that cement production is carried out at high temperatures such as 1400-1500oC, it requires the consumption of high amounts of energy. The share of energy in cement production costs is almost 70% Turkey, which has to import most of its energy, also ranks high in the world rankings in cement exports. While domestic resources are not used in cement production, the use of imported energy makes Turkey a mere middleman. Moreover, when environmental pollution and carbon dioxide emissions are taken into account, the quality of life is more of a disadvantage than an advantage for Turkey. Increasing the production of concrete without the use of cement and increasing the production and use of geopolymer concrete will make a significant contribution to energy saving by eliminating the need for energy. In geopolymer concrete research, research is usually conducted to reduce the cement substitution rate. The cement substitution rate is reduced by using waste materials such as pozzolanic volatile particles, groundmass, silicidumane, etc. If this approach spreads all over the world, cement production can be expected to decrease. As a result of many studies, it has been revealed that pozzolanic materials have a positive effect on concrete. It has been found that pozzolanic materials improve the durability of concrete and extend the service life of concrete. As a result of research, the use of pozzolanic materials in concrete production is seen as an effective technique to create high quality concrete with better properties and durability than fresh concrete (Hamalı, 2007). Thus, it will be possible to utilize waste materials, reduce environmental impacts and improve concrete performance.