Self-Healing Capability of Fibre Reinforced Cementitious Composites

Abstract

In order to investigate the self-healing capability of fibre reinforced cementitious composites (FRCC), mechanical properties and surface morphology of crack in FRCC were studied. Three types of FRCC specimens containing (1) polyethylene (PE) fibre, (2) steel cord (SC) fibre, and (3) hybrid fibres composite (both of PE and SC) were prepared. These specimens, in which cracks were introduced by tension test, were retained in water for 28 days. The self-healing capability of the specimens was investigated by means of microscope observation, water permeability test, tension test and backscattered electron image analysis. It was found that many very fine fibres of PE were bridging over the crack and crystallization products became easy to be attached to a large number of PE fibres. As a result, water permeability coefficient decreased and tensile strength was improved significantly. Therefore amount of the PE fibre per volume was indicated to have a great influence on self-healing. Furthermore, by means of backscattered electron image analysis, it was also shown that the difference of hydration degree in each FRCC has only little influence on the self-healing capability in case of the employed test series.

Recovery of Protective Performance of Cracked Ultra High Performance-Strain Hardening Cementitious Composites (UHP-SHCC) Due to Autogenous Healing

“…Yang et al (2009) also reported on the recovery of stiffness in ECC under wet and dry cycles. Homma et al (2009) investigated the self-healing phenomena of different types of FRCCs including a hybrid fiber system, and they confirmed the recovery of water tightness and tensile strength.…”

Observation of fracture sealing in high-strength and ultra-low-permeability concrete by micro-focus X-ray CT and SEM/EDX

“…While Heap et al (2013) showed that the water permeability of concrete increases significantly with the progress of fracturing, it is also possible that the sealing of existing fractures and pores affects the permeability of concrete. So far, various reports on the fracture sealing of concrete have been published (e.g., Jacobsen and Sellevold 1996;Hearn and Morley 1997;Hearn 1997;Edvardsen 1999;Reinhardt and Jooss 2003;Granger et al 2007; Van der Zwaag 2007;Homma et al 2009;Qian et al 2009;Yang et al 2009;Ahn and Kishi 2010;Wu et al 2012;Fukuda et al 2012;Fukuda et al 2013). Among this literature, Edvardsen (1999) showed that the sealing of a fracture occurs by the precipitation of calcium carbonate, generated from CO 3 2− in the water and Ca 2+ in the cement paste, and that the fracture aperture and applied water pressure significantly affect the sealing, while the types of cement and aggregate and the hardness of the water have no influence on the sealing rate.…”

“…For concrete of sufficient age, the formation of calcium carbonate primarily occurs (e.g. Jacobsen and Sellevold 1996;Hearn and Morley 1997;Hearn 1997;Edvardsen 1999;Van der Zwaag 2007;Homma et al 2009;Qian et al 2009;Yang et al 2009). While Heap et al (2013) showed that the water permeability of concrete increases significantly with the progress of fracturing, it is also possible that the sealing of existing fractures and pores affects the permeability of concrete.…”

Advances in Self-healing Cementitious Materials

“…They concluded that self-healing was not as robust as that observed in some experimental results carried out under controlled laboratory conditions, though the self-healing in the natural environment was promising. Homma et al (2008) investigated the self-healing capability of FRCC by microscope observation, water permeability test, tension test and backscattered electron image analysis. They prepared specimens with water/binder ratio of 0.45, containing three different types of fiber (i.e.…”