The Effects of Recycled Tire Rubbers and Steel Fibers on the Performance of Self-compacting Alkali Activated Concrete

In this study, the effects of recycled tire rubbers (RTR) and steel fiber (SF) on the fresh and hardened state properties of the self-compacted alkali activated concrete (SCAAC) were investigated. The ground granulated blast furnace slag, 1 % hooked-end SF, and two types of RTR were utilized. The crumb rubbers (CR) and tire rubber chips (TCR) were used as a substation to natural aggregates at substation levels of 10 % and 15 %. The fresh state performances were evaluated by T50 value, slump flow, V-funnel, and L-Box tests, while mechanical performances were assessed through compressive, flexural, and splitting tensile strength tests. Also, detailed crack and microstructural analyses were conducted. The RTR adversely affected the fresh state properties, which reduced more with SF inclusions. Among the RTR, the TR specimens exhibited lower fresh state performance than the CR specimens. Similar mechanical strengths were obtained on the TR and CR specimens under the same replacement ratios. However, TR specimens exhibited higher deformation capacities than the CR specimens, when SF was utilized. The SCAAC specimens with 1 % SF and 15 % RTR showed more and wider flexural cracks, higher mechanical strength, and deformation capacity, which can be utilized in structural applications, particularly in high seismic zones

Fire Resistance Performance of Fiber Reinforced Geopolymer Concrete: Review

Geopolymer is a relatively new substance that has sparked a surge of research into nearly every field of geopolymers in recent years. It's still on the verge of becoming a competitive OPC concrete alternative. Mechanical, hardness, and fire resistance properties of geopolymer are exceptional. There has been no/limited research on the effect of fiber integration on fire resistance of geopolymer concrete. In fire-exposed concrete, fiber can help to resist spalling. The goal of this study is to develop materials that exhibit eco-friendly properties and better fire-resistant behavior. Moreover, the combined effect of binder materials and different fibers on the fire resistance of geopolymer concretes. According to the findings, the fire resistance of fiber-reinforced geopolymer concretes increased in the order of carbon fiber-based GPC, micro-steel fiber-based GPC, hooked steel fiber-based GPC, and polypropylene fiber-based GPC. Furthermore, as compared to slag and metakaolin-based GPC, fly ash-based GPC has greater stability and fire resistance. Fiber-reinforced GPC can also be used as a sustainable and durable building material in various construction applications where high performance is needed