The effect of the degree of cracking on the state of stress and cracks width in elements with restrained boundary conditions

Abstract

A new and more precise model of cracking of reinforced concrete elements subjected to imposed strains is presented. A key question is how in the stress classic approach to take account of the effect of element relaxation (after each cracking episode) on cracks width reduction and other cracking criteria. Such a model would enable the calculation of the maximum cracks width depending on the cracking stage (i.e., the stage of cracks formation or that of stabilized cracks). This phenomenon is important particularly in semi‐massive structures in which the condition of watertightness must be fulfilled. The model has been validated based on the experimental studies available in the literature. For higher levels of strain the cracks widths have been found seriously underestimated after European standards (especially in elements with higher reinforcement ratio) while the calculations performed following the proposed model indicate proper estimation of cracks width.

Shrinkage cracking in restrained FRC members containing conventional reinforcement

“…1 A key criticism of this approach is that the reduction of the restraining forces due to cracking and its effect on crack spacing and crack widths are not adequately captured. [9][10][11] It is well established that the inclusion of short discrete fibers (steel, polypropylene, etc.) in concrete can significantly improve the cracking behavior of reinforced concrete.…”