Experimental and Numerical Investigation of the Fracture Behavior of Particle Reinforced Alkali Activated Slag Mortars

TL;DR

This study investigates how waste iron powder particles enhance the fracture resistance of alkali-activated slag mortars through experimental and numerical methods, showing increased ductility and energy dissipation.

Contribution

It introduces a combined experimental and XFEM simulation approach to analyze fracture behavior in particle-reinforced AAS mortars, highlighting the role of elongated iron particles as micro-reinforcements.

Findings

Increased fracture process zone area with iron particles

Enhanced crack growth resistance observed in experiments

XFEM simulations accurately predict fracture characteristics

Abstract

This paper presents fracture response of alkali-activated slag (AAS) mortars with up to 30% (by volume) of slag being replaced by waste iron powder which contains a significant fraction of elongated particles. The elongated iron particles act as micro-reinforcement and improve the crack resistance of AAS mortars by increasing the area of fracture process zone (FPZ). Increased area of FPZ signifies increased energy-dissipation which is reflected in the form of significant increase in the crack growth resistance as determined from R-curves. Fracture response of notched AAS mortar beams under three-point bending is simulated using extended finite element method (XFEM) to develop a tool for direct determination of fracture characteristics such as crack extension and fracture toughness in particulate-reinforced AAS mortars. Fracture response simulated using the XFEM based framework correlates well with experimental observations. The comprehensive fracture studies reported here provide an economical and sustainable means towards improving the ductility of AAS systems which are generally more brittle than their conventional ordinary portland cement counterparts.