An experimental study on transfer length of prestressing strand in self- consolidating concrete

摘要

Due to its economic advantages, the use of self-consolidating concrete (SCC) has increased rapidly in recent years. However, because SCC mixes typically have decreased amounts of coarse aggregate and high amounts of admixtures, industry members have expressed concerns that the bond of prestressing strand in SCC may be compromised.Therefore, the objective of this research program was to investigate the transfer lengths of prestressing strand in SCC. Transfer lengths of 12.5 mm diameter (0.5-in.), Grade 270 prestressing strand were evaluated using rectangular beams constructed from normal and high strength conventional concrete and SCC mixes. Strain readings over 56 days were used to calculate transfer lengths of beams. Results indicated that bond performance of SCC is superior to conventional concrete and that AASHTO and ACI equations for transfer length were generally conservative.