Effect of PVA fiber on properties of geopolymer composites: A comprehensive review

Abstract

Geopolymer composites (GC) have drawn much attention regarding sustainable cementitious materials in recent years. Polyvinyl alcohol (PVA) fiber is often added into GC to improve properties of the composite. In order to better understand the effect of PVA fiber on properties of GC and its mechanism, this paper sums up the advance in properties of PVA fiber-reinforced geopolymer composites (PVA-FRGC). Viscosity of GC increases with the increase of PVA fiber, so a reduced setting time and poor flowability of GC occurs. This paper expounds that PVA fiber with moderately high content and short length has significant effects on mechanical properties of GC. Most mechanical performances of GC can be tremendously improved thanks to fiber-bridge effect. Besides, it's worth noting that 0.2%–0.3% content of PVA fiber has optimal enhancement in compressive strength of GC. The details also contain the enhancement of PVA fiber incorporation on durability of GC, and related models used in predicting performance of PVA-FRGC are expounded. In addition, the strengthening mechanism from scanning electron microscope (SEM) images showed that PVA fibers had strong chemical bond strength and friction bond strength with geopolymer matrix, and future work need to be done is recommended. In general, PVA-FRGC has an excellent performance on mechanical properties and durability compared with plain GC. The paper is designed to make contributions for development of green building materials. This paper aims to provide guidance for the application of PVA fiber in GC and serve as support for practical application of PVA-FRGC in construction engineering.

Keywords

• PVA fiber-reinforced geopolymer composites
• Flowability
• Mechanical properties
• Durability
• Strengthening mechanism