In this study, the fresh properties, fracture energy, compressive strength, and flexural strength of self-compacting concrete including glass or basalt fibers were examined, and the effect of fibers on these properties were studied comparatively. For this purpose, fibers having three different lengths (6, 12, and 24 mm) were used in two different contents (2 and $4\mathrm{kg}/{\mathrm{m}}^3$ ). The workability of concrete mixtures decreased with fiber addition. The negative effect of basalt fibers on workability was greater than that of the glass fibers. The reduction in flow diameter was up to 40% and 44% as well as the reduction in L-box ratio was up to 41% and 48% in glass and basalt fiber mixtures, respectively. While the fiber addition generally reduced the compressive strength, it increased the flexural strength and fracture energy significantly. Increase in flexural strength was up to 58.6% in glass fiber and 43.5% in basalt fiber mixtures. The fracture energies of glass and basalt fiber mixtures were up to 55.1% and 30.4% higher than that of the control mixture, respectively.

N this study, the effect of the curing method and polyvinyl alcohol (PVA) fiber inclusion on some engineering properties of fly ash-based geopolymer mortars was examined. In this context, six fly ash-based mortars were produced using sodium hydroxide and sodium silicate solution. The fracture energy values were determined with notched samples of 50×50×240mm dimensions, and a clip-on gage was used to measure the crack mouth opening displacements. The notch width and notch height were 3 mm and 10 mm, respectively. Specimens were cured in hot water (80 °C) for 18 hours. Before curing, one series of samples was sealed with three layers of polyvinyl chloride (PVC) cling film and two layers of duct tape, while the other was not. The results showed that sealing the specimens during curing increased the compressive strength, and these increases were 18% for the reference mortar and 18% and 12%for mortars produced with 6 mm and 12 mm PVA fiber, respectively. Sealed curing enhanced fracture energy and peak loads and reduced the rate of capillary water absorption. With fiber inclusion, increases of up to 1508% in fracture energy values were achieved. The results revealed that sealing samples during curing significantly affects the mechanical properties.

Using recycled aggregates is crucial for a more sustainable environment and economy. In this study, the properties of recycled aggregate-based SIFCONs were examined. In the scope of the study, compressive strength, high-temperature resistance, sorptivity, and fracture energy of SIFCONs produced with recycled aggregate were investigated. The results were compared with those of the limestone-bearing SIFCONs. It was determined that the compressive strength and fracture energy of SIFCONs produced with recycled aggregate were 61.2 MPa and 14.9 N/mm, respectively. Although these values are lower than those of SIFCONs produced with limestone, it has been determined that recycled aggregates are advantageous in high-temperature resistance. The results demonstrated that the recycled aggregate could be used to produce SIFCON.