Study on relative shrinkage of cement-based micro-concrete for durable concrete repair

Abstract

This paper presents the investigation into the crack formation in micro-concrete due to their bond strength and drying shrinkage under normal and accelerated drying conditions at the interface between the substrate and micro concrete in a concrete repair. Investigated six different cement-based micro-concretes about their grain size, compressive strength, bond strength, and relative shrinkage values due to normal and raised drying temperature. Finite element analysis and microscopic study of crack development at the interface were investigated to strengthen the analysis of the crack developments. It was observed that the bond strength and drying shrinkage of the micro concretes influence the formation of cracks at the interface due to the relative shrinkage of the substrate and the micro concrete. The micro-concrete having high bond strength as compared to low bond strength micro-concrete, exhibits low crack width even though free drying shrinkage values are high in both case. Early detection of cracks at the interface in 3 days due to the combined effect of bond strength and drying shrinkage under accelerated drying conditions can be a helpful tool for selecting the micro concretes for concrete repair.

Keywords

• Micro concrete
• Differential shrinkage
• Concrete repair
• Drying shrinkage
• Bond strength
• Repair materials