Cracking behaviour of cast in situ reinforced concrete slabs with control joints

This paper presents the results of a study on the cracking behaviour of cast in situ reinforced concrete slabs with control joints. Material property tests were conducted to establish time-dependent concrete mechanical properties. Cast in situ reinforced concrete slabs with control joints were tested for up to 6 months to study the distribution of concrete cracks and development of concrete strains. A finite element method based model was developed, verified and used for a parametric study. It was found that using control joints can successfully regulate the concrete cracks. The slabs with longer joints suffered less cracks at the edges. The influence of the joint depth was insignificant; however, the joints cut all the way through the slabs caused higher tensile strains than those of shallower cuts. It was also found that the reinforcement ratio and concrete proportion had a significant effect on the cracking of the jointed concrete slabs.