(i) Spalling reinforcement is crucial in areas behind the loaded anchor blocks, where spalling stresses develop. These stresses, arising from strain incompatibility due to Poisson’s effect or stress trajectory patterns, can cause surface concrete to break away. Spalling reinforcement mitigates this risk, ensuring structural integrity.
(ii) Equilibrium reinforcement becomes necessary when dealing with multiple anchorages where prestressing loads are applied in sequence. This reinforcement helps maintain the structural balance and stability of the member by distributing the prestressing forces effectively.
(iii) Bursting reinforcement is essential to counteract the tensile stresses induced during prestressing operations. These stresses are most pronounced where stress trajectories curve towards the load’s line of action, leading to potential bursting. By providing adequate reinforcement, these lateral tensile forces can be effectively resisted, preventing structural failure.