| Abstract [eng] |
Due to the high cost of material transportation, shotcrete technology is a rarely chosen construction method in Lithuania. The use of local raw materials for production of this type of concrete would solve this problem and allow to improve and popularize shotcrete technology. The final master's thesis investigates the durability properties of shotcrete made from local raw materials. The aim of the thesis is to analyze the influence of the accelerator on the porosity, physical and mechanical properties of the material, freeze-thaw and corrosion resistance. The thesis consists of three main parts: literature review, research methodologies, results ant their discussion. In the theoretical part, the possible production technologies of shotcrete mixture and the materials are analyzed. Also, in this section the properties of Cast-in-Place and sprayed concrete are compared. The second part describes how the freeze-thaw resistance, corrosion resistance, water permeability, water absorption and porosity test is performed to determine effect of the amount of accelerator on the shotcrete durability. This section also describes the procedure for determining the compressive strength and density, the test materials and their concentrations. In the third part, the test results are presented and analyzed. The structural parameters of shotcrete produced in laboratory and sprayed on site are graphically compared. Studies have shown that the durability properties of shotcrete are related to the amount of accelerator added to the mix. High levels of additive can lead to a noticeable decrease in compressive strength and density, increase absorption and effective porosity. |
