Investigation of engineering properties of geopolymer concrete produced by electrical curing

In this thesis, the physical and mechanical properties of geopolymer concrete produced by electrical curing were investigated. The thesis study includes two stages of experimental and one stage of cost analysis in the form of preliminary design based on workability and mechanical performance in mortars, final concrete design for relative comparison, and comparative energy consumption evaluation to determine energy consumption. In the first stage of the study, thermal curing was applied at 45, 60, 80, 90, 100, and 120 °C for 24 hours, and electrical curing was applied to mortar mixtures with constant Ms modulus and Na2O concentration at voltage values of 10, 20, 25, 30, 35 and 40 volts for 6, 12 and 24 hours to determine the optimum thermal curing temperature to determine the applicable electrical curing parameters. In the first step, 36 different mortar mixes were prepared with the Ms modulus increased parametrically from 0.5 to 2.0 with an increase of 0.25 and 0.1. The Na2O content for each Ms modulus is 6 – 8 and 10 wt% of the powder material which is the aluminosilicate source. 4 mortar mixtures giving the best workability and compressive strength were selected and these mortars were selected for electrical curing with 20, 25, 30, and 35 V voltage and thermal curing with 60, 80, 100, and 120 °C temperatures determined in the preliminary experiments. Applied for 6 – 12 hours. Mortars providing sufficient workability and similar compressive strength were selected for both curing methods and passed to the second stage of experiments. In the second stage of the study, the selected mortars were cured at 100 °C and a voltage of 25 volts for 6 hours in both curing applications, and concrete samples were produced. The physical and mechanical properties of the produced concrete samples were evaluated comparatively. In the last stage, the energy consumption of both curing methods was analyzed comparatively in terms of cost, taking into account the electricity unit prices of different countries from Europe, America, and Asia. As a result, it has been seen that it is possible to produce geopolymer concretes by applying electrical curing with physical and mechanical properties similar to both conventional concrete and geopolymer concrete produced by thermal curing. In addition, in geopolymer concretes produced with electrical curing appears to be a much more energy efficient approach. This curing application can be used to produce geopolymers because of the fact that sufficient compressive strength can be obtained even in lower voltage values compared to conventional concretes produced with similar curing application, and there is a lower energy consumption compared to geopolymer concretes produced with thermal curing application. This result was achieved by ignoring the efficiency parameters such as the number of materials put in the oven and the heating time of the oven, and it can be said that there is a need for research with more parameters, especially on efficiency.