Research on the mechanical properties of polyvinyl alcohol-modified waste rubber-filled cement paste using digital image correlation technology

The incorporation of waste rubber into concrete has significant environmental value. However, a hydrophobic waste rubber surface results in poor adhesion to concrete, which damages the mechanical properties of concrete. In this paper, polyvinyl alcohol (PVA) is used to modify the waste rubber and the mechanical properties of PVA-modified waste rubber-filled cement paste are examined using digital image correlation (DIC) technology. According to the results, the addition of PVA increases the compressive strength and flexural strength of waste rubber-filled cement paste by 7.9%-15.4% and 12.7%-25.0% at the different curing ages with the content of waste rubber is 25%, respectively. In addition, the specimen exhibits higher integrity after complete destruction in the compressive strength and flexural strength tests as the waste rubber content increases. More importantly, DIC provides a good analysis of the full field displacement and strain in the compressive strength and flexural strength tests of PVA-modified waste rubber-filled cement paste. At the same time, DIC can accurately capture the generation and development of surface cracks on the specimen. The calculated results of the displacement and strain fields visually demonstrate the strengthening effect of PVA on the waste rubber-filled cement paste, especially the inhibition of crack development by PVA.