Investigation of the effect of sulfuric acid on ground pyrophyllite powder and blast furnace slag added mortars

Mineral additives are preferred to improve the physical, mechanical and durability properties of cement-based composites and to reduce the use of cement. By improving the physical, mechanical and durability properties of cement-based composites, it is possible to make engineering structures more durable and long-lasting. Reducing the use of cement ensures the prevention of environmental pollution and high cement production costs. Within the scope of this study, the effects of ground pyrophyllite powder (GPP) and blast furnace slag (BFS) materials used with, 5%, 10% and 15% by weight substitution with cement on mechanical and physical properties and sulfuric acid (SA) resistance of the mortars were investigated. In the production of mortar samples, CEM I 42.5/R type Portland cement was used as binder and 0-4 mm crushed sand was used as aggregate. The flexural and compressive strengths, ultrasonic pulse velocity, capillary water absorption coefficients, water absorption and porosity values of mineral added and unadulterated mortars that produced in laboratory with dimensions of 40x40x160 mm and their weight and strength loss values due to SA effect were investigated comparatively. According to the data obtained as a result of experimental studies, it has been determined that GPP can be used as mineral additive. It has been determined that the mortar samples produced by using GPP have higher resistance to sulfuric acid attacks than unadulterated and BFS added mortars, reduce weight losses by up to 21% and compressive strength losses by up to 30%.