Self-healing properties of cement-based and alkali-activated slag-based fiber-reinforced composites

This paper presents an experimental study of the self-healing properties of cement-based and alkali-activated slag-based fiber-reinforced composites with controlled crack width. Two types of binder, i.e. cement and alkali-activated slag-based polyethylene fiber-reinforced composites with identical water-to-binder ratios, were designed. Compressive strength and uniaxial tension tests were performed to measure the mechanical properties of the composites, and the self-healing performance was investigated by observation of the crack width and by measuring resonance frequency. Scanning electron microscopy and energy-dispersive X-ray spectroscopy were also adopted to analyze the morphology and chemical composition of the healing materials. The test results showed that alkali-activated slag-based composites have advantages compared to cement-based composites in terms of a reduction of relative crack width; however, cement-based composites have a higher resonant frequency recovery than alkali-activated slag-based composites. It is also observed that calcium carbonate is the dominant healing material of cement-based and slag-based composites.