Examination of engineering properties of silica aerogel added lightweight concrete produced using volcanic tufa wastes

In the thesis study, silica aerogel (SA) synthesis was achieved using Bayburt Stone (BT) waste, which is a volcanic tuff stone. The results of the change of SA in lightweight concrete such as heat and sound insulation, leakage and porosity were investigated. The study provides an environmentally friendly production and aims to introduce lightweight concrete with high thermal stability and improved voltage properties to the construction industry. In the first stage of the study, SA synthesis was performed using BT attacks. In the second stage, lightweight concrete with SA additives was produced. Physical (unit volume weight, porosity, water absorption, thermal conductivity and ultrasound transmission rate) and mechanical (pressure test) tests were performed on the samples and the results were interpreted by ANOVA analysis. In addition, structural characterization (XRD, TEM, FT-IR, TGA/DTA and SEM) analyzes and optical microscope imaging of the samples were performed. Taguchi method was used to determine the lightweight concrete with optimum thermal insulation. In lightweight concrete, the L8 (41*22) orthogonal series was selected by determining the SA rate (0, 1, 2 and 3%), cement dosage (300 and 350) and mixing water rate (0,40 and 0,45). The study determined that thermal insulation would be optimum at levels (3, 350 and 0,40). It was determined that (3%) SA substitution in lightweight concrete improved the thermal conductivity value (46%), increased its porosity (31,48%) and caused a decrease in temperatures (9,72 MPa). In the characterization studies: It is evaluated that SA is hydrophobic and has good adsorption properties, that it consists of communities all over the SA in the concrete, and that multicrystals in the concrete increase with the proliferation of SA, and this increase causes a decrease in its physical breakage. In thermogravimetic analysis, while the mass loss observed at 1000 °C was 27% with 0% SA change, it was observed that this value decreased to 21% with 3% SA change, and this was considered as an indicator that the increase in SA change increased the thermal durability of concrete. In addition, it is considered that SA has a great impact on obtaining high quality lightweight concrete and waste BT will positively affect the regional economy.