Investigation of physical and mechanical properties of pozzolan substituted gypsum plasters strengthened with natural and artificial fibers

Due to the rich gypsum reserve in our country, easy production methods and low cost, it is important for gypsum to find a wider area of use both in terms of economy and energy saving; plaster, which is one of the oldest building materials used in human history, is a good sound and heat insulator, but with low mechanical properties. In this thesis, it is aimed to obtain gypsum plasters with high mechanical properties and water resistance by adding silica fume, blast furnace slag, hemp fiber and glass fiber to gypsum at different rates. Mixing ratios were determined using the Taguchi method, and thus, more parameters were analyzed with less number of experiments, and comprehensive results were obtained. The use of the Taguchi method adds value to the study in terms of saving time and materials. In the study, silica fume and blast furnace slag were used at the rates of 0%, 10%, 20%, 30%, hemp fiber and glass fiber 0%, 0.2%, 0.4%, 0.6%. The water/binder ratio was kept variable as 0.6 and 0.7. In order to test the workability of gypsum plasters, spreading table and setting time tests were carried out on fresh mixtures. Flexural strength, compressive strength, ultrasound transmission rate, capillary water absorption and unit weight tests were performed on the produced gypsum plaster samples, and the results were analyzed by the Taguchi method. In addition, mineralogical and morphological properties were defined by using SEM, EDS and XRD analyzes in the microstructure examinations of the produced samples. According to the data obtained, the contribution of pozzolan; It has been determined that it causes a decrease in compressive and flexural strengths, but has a healing effect in filling capillary spaces. As the fiber additive increased, the flexural strength values of 7 and 28 days increased.