EFFECT OF SLAG CONTENT ON SELF-HEALING PROPERTIES OF CEMENT MORTAR

Ruihua Liang, Lei Zhang,Xiao Kou, Hui Rong, Xueping Wang

ABSTRACT: The effects of different content (10,20,30%) of slag on the hydration characteristics of cement and the self-healing properties of cement mortar were studied. The hydration heat, hydration products, mechanical properties and micro-structure of cement mortar were characterized by Digital cement hydration heat meter, X-ray diffraction (XRD), Ultrasonic nondestructive testing instrument and Scanning electron microscope (SEM) etc. The self-healing capacities of cracked cement mortar were characterized by strength restoration ratio and changes of ultrasonic wave. The results show that the accelerating period of cement hydration is prolonged with the increase of slag content; and the early hydration exothermic temperature decreased . The strength restoration ratio of mortar and the change of ultrasonic wave have similar laws, both of which decreased first and then increased with the increase of the content of slag, and the effect is best when the slag content is 30%. The strength restoration ratio increases with increasing water in the curing conditions.

Keywords: cement, slag; mortar, self-healing