Properties of ultra-high-performance mortar containing eco-friendly wollastonite micro-fibers for green and sustainable infrastructure

Abstract

Wollastonite has become one of the potential pozzolanic microfibers material that can be used to improve the characteristics of cement-matrix composites. This study was conducted with the aim to investigate experimentally the properties of high-strength mortar containing wollastonite as an additive material with percentage of 1.2, 2.4, 4.8, and 9.6% by weight of binders. Water and sand to binder ratio of 0.2 and 2.5, respectively, were used to form high-strength mortar specimens for mechanical properties testing including compressive strength and three-point loading on flexural strength test. Microstructural analysis was also conducted to assess the reinforcing effects and hydration products that might be affected due to the inclusion of wollastonite micro-fibers. The results show that mortar with 1.2-4.8% of wollastonite content reached 12% higher resistance on compression load with respect to the control mortar. More significant improvement can be observed in flexural strength results whereas the wollastonite showed its reinforcing capability in bridging the micro-cracks resulted in more ductile and toughness matrix in carrying the high load carrying capacity. Moreover, wollastonite also has a capability to pore refinement as evident from the sorptivity results. Furthermore, wollastonite micro-fibers can be an alternate source material for durability improver that leads to sustainable infrastructure.