Compressive strength prediction of crumb rubber mortar based on mesoscale model

A mesoscale model was developed to study the compressive performance of crumb rubber mortar (CRM). The internal structure of CRM was considered as a three-phase composite consisting of rubber, mortar, and interfacial transition zone (ITZ). The effects of ITZ, rubber aggregate distribution, mortar matrix strength, rubber aggregate shape, and treating rubber as pores on the compressive strength of CRM were studied. The influence of the presence of ITZ on the compressive strength of CRM was lower than 2 % and was negligible. The location of rubber particles has an effect on the strength of CRM. The use of small-sized rubber particles resulted in a more uniform internal structure of the CRM samples and less variation in strength among different samples. Adding rubber reduces the compressive strength of mortar, and the strength reduction rate is mainly affected by the rubber content. Rubber particles can be equivalent to pores to analyze their influence on the compressive strength and failure mode of CRM. The stress concentration that occurs around the position of the rubber particles is a major factor that causes the strength of CRM to decrease. A prediction formula was presented to calculate the compressive strength of CRM, which agreed well with the experimental results.