The Effect of Using Waste Tire as a Fine Aggregate on Mechanical Properties of Fly Ash-Substituted Self-Compacting Concrete

Wasted tyres are commonly used in civil engineering applications for a variety of purposes, including as concrete ingredients. Wasted tires that are mechanically sheared into shreds ranging in size from 25 to 300 mm and intended for use in concrete are called " Waste Shreded Tyre Aggregate" to make a contribution to sustainable waste management. Currently, at this point, the basic philosophy of this study is to investigate the effects of Waste Tire Aggregate (WTA) on the mechanical and durability properties of Self Compacting Concrete (SCC) to provide a contribution to reusing waste tires in the construction industry. WTAs with 5, 10, and 15% volume ratios are substituted for fine aggregate in SCC production. In addition, 15% mixtures with a binder quantity of 550 kg/m3, including 20 and 30% fly ash (FA) were substituted and prepared to be compared with the control concrete. To measure the rheological properties of SCCs, slump flow, V-funnel and L-box tests were performed. Then, the produced concrete samples of different sizes were cured under laboratory conditions for 28 days and then subjected to hardened concrete tests on the 28th, 56th and 90th days. The hardened concrete tests were composed of axial compressive strength, flexural strength, splitting tensile, diagonal tensile, abrasion resistance, modulus of elasticity. Finally, a durability test was performed as chlorine penetration depth. The test results show that WTA positively affects the properties of fresh and hardened SCC. Only, the increase in the substitution rate of WTA in concrete mixtures decreased the hardened state strength of the SCC. However, the addition of WTA to up to 15% of the total fine aggregate volume indicates that it is possible to apply recycled WTA to SCC and successfully satisfy both fresh and hardened SCC specifications.