Experimental investigation on bond behaviours of deformed steel bars embedded in early age concrete under biaxial lateral pressures at low curing temperatures

The unexpected temperature drop during the concrete curing process could degrade properties at early age, and then decrease bond behaviour between reinforcing steel bars. To assess effect of low on structural safety, it is significantly important to investigate age under such extreme environmental conditions. In this study, pull-out tests were conducted early-age specimens with embedded deformed bars 0 °C normal 20 °C. All subjected biaxial lateral pressures varying from 0.1 fcu 0.4 simultaneous confining pressure. results indicated that comparing cured °C, strength for decreased earlier ages 3 7 days. However, increased steadily increase age. Eventually, 28-day reached same both temperatures. addition, average slip displacements corresponding strengths was slightly lower than those temperature. Based experimental results, an empirical model stress-slip relationship proposed Comparing other existing models, agreed well validating its applicability