the behavior of high-strength lc3 concrete reinforced with recycled steel fiber under uniaxial compression and splitting tensile

This study assesses the stress-strain and load-deflection behavior of ordinary portland cement (opc) and limestone low kaolinite calcined clay cement (lc3) concrete under uniaxial compressive and indirect splitting loads. for this, ten concrete mixes were designed, half of which were lc3-based concrete. in the lc3-based concrete, 30% of cement was substituted with the limestone and calcined clay mixture. four different contents of recycled tire steel fiber (rtsf) were used for reinforcing the concrete. the uniaxial compression and indirect splitting tensile tests were performed on the cylinder specimens. peak strain, ultimate strain, absorbed energy, and toughness in compression were evaluated to assess the uniaxial compression behavior of plain and rtsf-reinforced opc and lc3-based concrete. also, absorbed energy and toughness in splitting were determined to examine the splitting behavior. the results demonstrated that at least 0.6% rtsf is required to develop the post-peak phase of the stress-strain curve under uniaxial compression. further, the lc3 concrete resulted in lower peak and ultimate strains under compressive load. incorporating 1.2% rtsf into opc concrete enhanced the peak and ultimate strains by about 20% and 94%, respectively. in addition, the inclusion of 0.9% rtsf in lc3 concrete improved the peak and ultimate strains by approximately 18% and 100%, respectively. furthermore, the lc3 concrete demonstrated better performance in the post-peak phase of splitting tensile. moreover, digital image correlation (dic) results demonstrated that incorporating rtsf into concrete effectively controls the initiation and propagation of cracks.