Evolution of Strength and Failure of SCC during Early Hydration

TL;DR

This paper investigates the early strength development and failure mechanisms of self-consolidating concrete (SCC) through mechanical tests, revealing two distinct regimes and their implications for industrial process control.

Contribution

It introduces a data collapsing procedure to identify two regimes in SCC strength evolution and discusses the transition from plastic deformation to crack growth behavior.

Findings

Identification of two regimes in SCC strength evolution

Development of a master evolution curve for SCC

Observation of differences in tensile and compressive strength at transition

Abstract

The early strength evolution of self-consolidating concrete (SCC) is studied by a set of non-standard mechanical tests for compressive, tensile, shear and bending failure. The results are applicable in an industrial environment for process control, e.g. of slip casting with adaptive molds in robotic fabrication. A procedure for collapsing data to a master evolution curve is presented that allows to distinguish two regimes in the evolution. In the first, the material is capable of undergoing large localized plastic deformation, as expected from thixotropic yield stress fluids. This is followed by a transition to cohesive frictional material behavior dominated by crack growth. The typical differences in tensile and compressive strength of hardened concrete are observed to originate at the transition. Finally, the evolution of a limit surface in principal stress space is constructed and discussed.