Performance of Carbon and Wool Fiber-Reinforced Limestone Calcined Clay Cement-Based Mortar

Limestone calcined clay cement (LC3) offers several benefits compared with ordinary portland cement (OPC), such as reduced CO2 emissions and cost-effectiveness. Substituting a significant portion of cement with calcined clay renders the new cement more sustainable than OPC. This study examines locally available nonkaolinite clayey soil in two phases. Initially, the calcination temperature, the substitution level of calcined clay, and the ratio of calcined clay to limestone were optimized. The strength activity index method was used to determine the best results according to current standards. The outcomes were 700°C, 20%, and a ratio of 3∶1, respectively. The optimum combinations were augmented with recycled sheep wool (Wl) fiber and carbon (CF) fiber at proportions of 0%, 0.5%, 1%, and 1.5% of the binder’s weight. The flowability of the fresh mortar was assessed. The mechanical parameters examined were compressive strength, flexural strength, and splitting tensile strength. The durability characteristics of fire resistance, water absorption, water sorptivity, and porosity were examined. The findings indicate that 1.5% and 1% of Wl and CF fibers had optimal mechanical and durability qualities. Increasing the dosage of CF and Wl fibers from 0% to 1% and 1.5% resulted in improvements in flexural strength of 15.65% and 6.6%, respectively. When CF and Wl fibers were increased from 0% to 1% and 1.5%, the splitting tensile strength increased by 15.57% and 35.15%, respectively. Nevertheless, the augmentation of fibers constantly diminished flowability. This study illustrates the feasibility of utilizing locally sourced clayey soil as a pozzolanic material for the production of LC3.