Assessment of early-age cracking of high-performance concrete in restrained ring specimens

摘要

High-performance concrete（HPC） is stronger and more durable than conventional concrete.However,shrinkage and shrinkage cracking are common phenomena in HPC,especially early-age cracking.This study assessed early-age cracking of HPC for two mixtures using restrained ring tests.The two mixtures were produced with water/binder mass ratio（mW/mB） of 0.22 and 0.40,respectively.The results show that,with greater steel thickness,the higher degree of restraint resulted in a higher interface pressure and earlier cracking.With steel thickness of 6 mm,19 mm,and 30 mm,the age of cracking were,respectively,12 days,8 days,and 5.4 days with the mW/mB = 0.22 mixture;and 22.5 days,12.6 days,and 7.1 days with the mW/mB = 0.40 mixture.Cases of the same steel thickness show that the ring specimens with a thicker concrete wall crack later.With the mW/mB = 0.22 mixture,concrete walls with thicknesses of 37.5 mm,75 mm,and 112.5 mm cracked at 3.4 days,8.0 days,and 9.8 days,respectively;with the mW/mB= 0.40 mixture,the ages of cracking were 7.1 days,12.6 days,and 16.0 days,respectively.