The effect of fine rubber waste on freeze thaw and sulphate resistance of blast furnace slag based geopolymer concretes

In this thesis, blast furnace slag based and thin waste rubber reinforced geopolymer concrete was produced and the resistance properties of these geopolymer concretes against sulfate and freeze-thaw resistance were investigated. For this purpose, 4 groups of geopolymer concrete were produced by using 0%, 5%, 10% and 15% volumetric waste rubber instead of fine aggregate and activated with KOH activator. After curing for 28 days, the produced concrete samples were kept in sodium sulfate and magnesium sulfate solutions for 4, 8 and 12 weeks. In addition, the samples that completed their curing times were exposed to 100, 200 and 300 cycles of freeze-thaw effect. During this period, the compressive strength, weight changes, capillary permeability, water absorption rates, pH values of the samples were examined and their visual changes and internal structures were examined. The obtained results were compared with the control samples. When the test results were examined, the compressive strength decreased as the waste tire ratio increased. However, it has been observed that the increase in the ratio of waste rubber in the concrete has a positive effect on sulfate and freeze-thaw resistance. The compressive strength values, water absorption rates and weights of the samples kept in sulfate solutions increased, while the capillary permeability coefficients decreased. Compressive strength values and weights of the samples under freeze-thaw effect decreased, capillary permeability coefficient and water absorption rates increased. The results obtained were supported by visual inspections and microstructure images. Keywords: Geopolymer concrete, blast furnace slag, waste rubber, freeze thaw resistance, sulphate resistance