THE RELIABILITY OF CRACK PREDICTIONS FOR HARDENING CONCRETE STRUCTURES

As clients focus more and more on the quality of infrastructural projects, emphasis is increasingly shifting towards a full life-cycle approach. The initiation phase of a project becomes the start of the quality challenge that covers a structures lifetime. The main challenge is the realization of a high standard product, which possesses maximum protection against aggressive forces during its lifetime, which especially holds for concrete structures. The success factor for achieving this objective depends on the one hand on the “design quality” of a structure and on the other hand on the “actual quality” of the concrete produced during hardening. The hardening phase of concrete becomes, in this respect, a governing parameter for the quality realized, especially when considering its long-term performance. Avoidance of thermal (micro-)cracking during the hydration of concrete is one of the processes that have to be controlled. The reliability of crack predictions for hardening concrete structures is therefore the main issue that requires due attention. In this contribution to the congress, the reliability of crack predictions for concrete structures will be addressed. Creep experiments and relaxation for different concretes will be presented, and compared with calculated results. The calculated results will be compared with experiments using the so-called Temperature Stress Testing Machine (TSTM). The results provide a clear picture about the reliability of crack predictions for concrete structures.

• INTRODUCTION

• TSTM TESTING PROGRAMME

• STRESS AND STRENGTH CALCULATIONS

• PROBABILISTIC APPROACH FOR EARLY-AGE CRACKING

• CONCLUSIONS AND RECOMMENDATIONS

• REFERENCES