The effect of freezing and thawing cycles on mechanical properties of concrete (compressive, splitting tensile strength) was experimentally investigated. According to the pullout test data of three kinds of deformed...The effect of freezing and thawing cycles on mechanical properties of concrete (compressive, splitting tensile strength) was experimentally investigated. According to the pullout test data of three kinds of deformed steel bars, the bond stress-slip curves after freezing and thawing were obtained. The empirical equations of peak bond strength were proposed that the damage accounted for effects of freezing and thawing cycle. Meanwhile, the mechanism of bond deterioration between steel bars and concrete after freezing and thawing cycles was discussed. All these conclusions will be useful to the durability design and reliability calculation of RC structures in cold region.展开更多
The size effect of tension round bars with circumferential crack was described and used to measure the plane-strain fracture toughness K_(1c) of median or low strength steel.The size of cylindrical specimen required f...The size effect of tension round bars with circumferential crack was described and used to measure the plane-strain fracture toughness K_(1c) of median or low strength steel.The size of cylindrical specimen required for K_(1c) measurement is much smaller than that of standard specimen.The J-integral values of the cylindrical sqecimens were calculated to characterize the size effect.The finite element calculution and fracture morphology analysis have been conducted to eyplain the fact that smaller cylindrical specimen could be used to measure K_(1c) of median or low strength steel.展开更多
In order to investigate the tensile bond anchorage properties of Australian 500N steel bars in concrete,111 pullout tests were conducted.The precise bond slip values have been gained by using the laser displacement se...In order to investigate the tensile bond anchorage properties of Australian 500N steel bars in concrete,111 pullout tests were conducted.The precise bond slip values have been gained by using the laser displacement sensor with high resolution,including the complete bond-slip curves.How the main anchorage factors such as concrete strength,bar diameter(8,10,12,16,20,24,28,32 and 36 mm) the concrete covered,embedded length and transverse reinforcement influencing the bond anchorage properties was studied under tensile condition.The process of the tensile force-slip failure for Australian 500N reinforcing steel can be divided into five stages:elastic stage,local slip stage,slip in ascent stage,slip in descent stage and remnant stage.The formula for calculating the tensile bond strength of Australian 500N reinforcing bar in concrete was proposed according to the test results,including the consistent model for tensile bond-slip relationship.展开更多
基金the National Natural Science Foundation of China(No.50479059)
文摘The effect of freezing and thawing cycles on mechanical properties of concrete (compressive, splitting tensile strength) was experimentally investigated. According to the pullout test data of three kinds of deformed steel bars, the bond stress-slip curves after freezing and thawing were obtained. The empirical equations of peak bond strength were proposed that the damage accounted for effects of freezing and thawing cycle. Meanwhile, the mechanism of bond deterioration between steel bars and concrete after freezing and thawing cycles was discussed. All these conclusions will be useful to the durability design and reliability calculation of RC structures in cold region.
文摘The size effect of tension round bars with circumferential crack was described and used to measure the plane-strain fracture toughness K_(1c) of median or low strength steel.The size of cylindrical specimen required for K_(1c) measurement is much smaller than that of standard specimen.The J-integral values of the cylindrical sqecimens were calculated to characterize the size effect.The finite element calculution and fracture morphology analysis have been conducted to eyplain the fact that smaller cylindrical specimen could be used to measure K_(1c) of median or low strength steel.
基金Project(DP0988940) supported by Australian Research Council Discovery Grant Program Project(2011M500930) supported by Postdoctoral Science Foundation of China+1 种基金Project(11KJB560003) supported by College Natural Science Foundation of Jiangsu Province,ChinaProject(163050072) supported by the Talent Introduction Foundation of Nanjing Forestry University,China
文摘In order to investigate the tensile bond anchorage properties of Australian 500N steel bars in concrete,111 pullout tests were conducted.The precise bond slip values have been gained by using the laser displacement sensor with high resolution,including the complete bond-slip curves.How the main anchorage factors such as concrete strength,bar diameter(8,10,12,16,20,24,28,32 and 36 mm) the concrete covered,embedded length and transverse reinforcement influencing the bond anchorage properties was studied under tensile condition.The process of the tensile force-slip failure for Australian 500N reinforcing steel can be divided into five stages:elastic stage,local slip stage,slip in ascent stage,slip in descent stage and remnant stage.The formula for calculating the tensile bond strength of Australian 500N reinforcing bar in concrete was proposed according to the test results,including the consistent model for tensile bond-slip relationship.