Acoustic emission analysis of self-healing properties in cementitious materials with superabsorbent polymers (SAPs) during different environments

This paper studies the coupling effect of superabsorbent polymers (SAPs) and fly ash on the self-healing performance of mortar. The three-point bending test was used to evaluate the mechanical property recovery effect of mortar specimens after curing in different environments, and the relationship between crack closure rate, flexural strength and flexural stiffness recovery was established. The amplitude and energy in acoustic emission were used to evaluate the characteristics of self-healing products. The results show that compared with the control specimens, the addition of SAP improves the crack closure rate and mechanical property recovery effect of mortar specimens. With the increase of SAP particle size and content, the mechanical property recovery rate and crack closure rate increase accordingly. The order of self-healing effect of specimens in different healing environments is saturated calcium hydroxide > water >97 % RH > air. After reloading, the amplitude number and cumulative energy of samples with SAP are larger than those of the control specimens. The SEM results also prove this, and the self-healing products in the crack area of the mortar specimens with SAP are denser than those in the control specimens.