Mechanical properties and durability of fiber reinforced geopolymer composites: A review on recent progressd

Abstract

Geopolymer concrete shares similar mechanical properties with ordinary Portland cement (OPC) concrete, and is even provided with better performances in high temperature and high corrosion circumstances. However, geopolymer binder is still subject to the disadvantages of large shrinkage and high brittleness, which greatly limit its application. Fiber reinforcement is widely used in various geopolymer systems to overcome the brittleness issue, but retains the high strength. Over the past 10 years, a significant advance has been made in the research of fiber reinforced geopolymers in terms of toughening efficiency and durability improvement. This paper, as a mini review, focuses on three types of fibers, i.e., inorganic fiber, natural fiber and synthetic fiber, in geopolymers, and their specific effects on compressive, flexural and tensile strengths, fractural toughness, shear strength and durability including shrinkage, chemical and freezing-thaw resistances. The recement understanding of bonding mechanism and fiber-geopolymer interface are also discussed, and knowledge gaps and future work challenges are correspondingly pointed out.

Geopolymer Cement in Pavement Applications: Bridging Sustainability and Performance

“…Geopolymer cement (GPC) generally provides better resistance to chemical attacks such as acid or base attack, chloride penetration, and sulfate attacks, which are common causes of deterioration in pavement structures [71,72]. The presence of fibers in GPC improves its chemical resistance, but an increase in porosity and pore size of geopolymers subjects them to easy deterioration by chemical attack [40].…”

“…This is the ability of a material to resist the effects of freeze and thaw cycles. The result of the freeze-thaw cycle has been used as an index for evaluating the durability of GPC [71,75]. The presence of fibers in GPC concrete lowers the porosity of concrete and improves the freeze-thaw cycle resistance [71,75].…”

“…The result of the freeze-thaw cycle has been used as an index for evaluating the durability of GPC [71,75]. The presence of fibers in GPC concrete lowers the porosity of concrete and improves the freeze-thaw cycle resistance [71,75]. In addition, due to the low water requirement and coupled with a high concentration electrolyte pore solution, the alkaliactivated slag-based GPC concrete can withstand 300-1150 cycles of repeated freezingthawing.…”

“…Adding fibers, such as polyvinyl alcohol (PVA) fibers, has been shown to improve the abrasion resistance of GPC [94,95]. Hence, GPC concrete generally shows a better abrasion resistance than Portland cement concrete [71].…”

“…This is regarded as the loss of capillary moisture from the hardened cement mixture matrix during air drying, leading to shrinkage and crack formation within the concrete. It is a crucial durability performance index that provides information on the potential cracks that can result in hardened cementitious materials [71]. Reports have shown that the fiber addition to the GPC matrix on production minimizes the stress in the matrix, making it withstand drying shrinkage better than Portland cement concrete [71,108].…”