In this study, the mechanical behaviors that can occur under the influence of high temperature in the mortars produced by silica fume and waste brick dust were investigated. For this purpose, Portland cement (CEM I), brick dust (BD) of brick factory waste, silica fume (SF) of ETI electrometallurgy INC. industrial waste CEN standard sand and water were used in the production of mortar. Blended cements were obtained by using BD, SF and SFBD at 5.0%, 10.0%, 15.0% and 20.0% ratio with substitution method in Portland cement. Density, Blaine, initial set and final set tests were performed on the produced mortars and 40x40x160 mm sized mortar prism samples were obtained using these cements. These samples were exposed to five temperature effects as 20, 150, 300, 700 and 900 degrees C. The mortar samples kept at 20 degrees C were accepted as reference mortar. A total of 1053 samples were studied in two different ways of cooling mortars as air-cooling (spontaneously at 20 degrees C +/- 2 in laboratory environment) and sprinkling (water spraying). After the mortar samples reached at room temperature, flexional resistance and compressive strength tests were carried out on 7th, 28th and 90th days. According to the test results; it was determined that BD, SF and SFBD can be used as pozzolanic additives in cement mortars both alone and together and can be evaluated in buildings with high probability of fire up to certain temperature values.