Investigation of the Effect of Ulexite Additive on the Mechanical Strength and Thermal Conductivity of Cement Mortar.

In this study, the effect of ulexite substitution in cement mortar and its physical and mechanical properties on cement mortar properties were investigated. First of all, the pozzolanic activity of the ulexite material was determined. Then, cement mortars with ulexite additives at different rates (0.5%, 1%, 2%, 4%); Specific gravity, specific surface, setting start and end times, consistency and expansion tests, as well as 7 and 28 days flexural and compressive strength of the mortar samples were determined and compared with the control sample. As a result of the study, with the increase of the ulexite substitution ratio, the set start and set expiration times were extended, and all of the ulexite-substituted cement mortars provided the lowest mechanical strength required in related standard. It was observed that the cement mortars with 0.5%, 1%, 2% ulexite substituted cement mortars exceeded the reference sample and the best replacement rate was in the mortars with 0.5% replacement. However, depending on the increase in the ulexite substitution ratio, a decrease in mechanical strength was detected among themselves. According to the results obtained from the thermal conductivity tests, the thermal conductivity values of the cement mortars decreased with the ulexite substitution. Depending on the ulexite substitution rate, the thermal conductivity value decreased by approximately 50%. The lowest thermal conductivity value was measured in the test sample with 4% ulexite substitute. [ABSTRACT FROM AUTHOR]