This research deals with the sensitivity of eight types of performance-designed high-strength concretes to the loading rate. Variations in concrete composition produce the desired performance, for in- stance, having null shrinkage or being able to be pumped at elevated heights…
This research deals with the sensitivity of eight types of performance-designed high-strength concretes to the loading rate. Variations in concrete composition produce the desired performance, for in- stance, having null shrinkage or being able to be pumped at elevated heights without segregation, but also produce variations in the fracture properties that are reported in this paper as well. The tests were performed -5 at five loading rates (loading point displacement rates) spanning six orders in magnitude, from 1.74×10 mm/s to 17.4 mm/s. Load-displacement curves show that the peak load increases with an increase in loading rates, whereas the corresponding displacement almost keeps constant. Fracture energy is not sensitive with the loading rates first when it is less than 0.01 mm/s, later, the rate effect on the fracture energy is quite re- markable. A formula with a cohesive term based on a cohesive law was adopted to analyze the results. This formula is in a good agreement with the experimental results and it allows obtaining the theoretical value of the fracture energy under strictly static condition.