Investigation of high temperature resistance of cementitious composites containing nanomaterials

In this thesis, high temperature durability and self-healing performance of cement-based composites (ECC) containing nano silica (NS) and carbon nano tube (CNT) were investigated. In the mixtures, NS and CNT were used at the rates of 0%, 0.25%, 0.50% and 0.75% by mass instead of binder. After producing samples of 505050 mm cube in size, 5075360 mm prismatic in size and Ø100200 mm cylindrical with these mixing ratios containing NS and CNT, they were cured in plastic bags at 23±2 °C for 28 days. After this curing period, compressive strength and flexural strength tests were carried out on the samples exposed to room temperature (20±2 ℃) and temperatures of 100 ℃, 200 ℃, 300 ℃ and 400 ℃. In addition, cracks were formed by preloading on Ø10050 mm cylindrical samples cut from the cylindrical samples exposed to these temperatures, and the self-healing behavior of these cracks with the wetting/drying cycle was investigated. After the wetting/drying cycles, splitting tensile strength rapid chloride permeability and ultrasonic pulse velocity tests were carried out on the recovered samples. Moreover, SEM, EDS, XRD and FTIR analyzes were performed on the samples from the healed specimens to examine the morphological characteristics of the self-healing products. When the compressive strength and flexural strength test results of ECC samples were examined, the best results were obtained from ECC samples containing NS. When the self-healing performance of ECC samples was examined, it was seen that the best healing sample was the ECC sample containing 0.75% NS.