In order to study the mechanical properties of damaged reinforced concrete(RC)beams reinforced with ultra-high-performance concrete(UHPC),a four-point bending test was conducted to systematically investigate the influ...In order to study the mechanical properties of damaged reinforced concrete(RC)beams reinforced with ultra-high-performance concrete(UHPC),a four-point bending test was conducted to systematically investigate the influence of factors such as the number of reinforcement surfaces and the degree of damage.The results indicate that single-sided repaired beams have certain advantages in crack resistance performance,but are more disadvantageous in ultimate bearing capacity,with obvious debonding phenomenon before the end of loading.Compared with single-sided reinforcement,the cracking load of the three-sided reinforced beam increased by an average of 1.85 times,the ultimate bearing capacity increased by an average of 177.5%,and a good UHPC-RC combination effect could be formed,which could work synergistically until the end of loading.The degree of pre damage has a significant impact on the crack resistance performance of reinforced beams,while its impact on the ultimate bearing capacity is relatively limited.When the pre splitting width of the RC beam increases from 0.2 mm to 0.4 mm,the ultimate bearing capacity decreases by 28.33%.展开更多
The contribution of chemical compositions in terms of carbon equivalent value（CEV） on impending crack propagation during weld bead bend tests（WBBTs） was studied with five different high-strength lowalloy steel pla...The contribution of chemical compositions in terms of carbon equivalent value（CEV） on impending crack propagation during weld bead bend tests（WBBTs） was studied with five different high-strength lowalloy steel plates that underwent different rolling processes. The test showed that cracks developed at the weld joint, easily passed through the coarse-grain heat-affected zone（CGHAZ）, and finally were arrested within the heat-affected zone（HAZ）. An apparent decrease in the average crack length, which consequently indicated improvement in crack arrestability, was found with decreasing CEV. In addition,the relatively fine microstructure in the HAZ of low-CEV steel plates helped in preventing the crack from further propagation. Special emphasis was placed on the empirical expectation of critical CEV above which WBBT might fail.展开更多
The influence of the most important parameters on the service life of reinforced asphalt overlay with geogrid materials in bending mode was examined by employing the Taguchi method and analysis of variance techniques....The influence of the most important parameters on the service life of reinforced asphalt overlay with geogrid materials in bending mode was examined by employing the Taguchi method and analysis of variance techniques. The objectives of this experiment was to investigate the effects of grid stiffness, tensile strength, coating type, amount of tack coat, overlay thickness, crack width and stiffnesses of asphalt overlay and existing asphalt concrete on propagation of the reflection cracking. Results indicate that the stiffnesses of cracked layer and overlay are the main significant factors that can directly improve the service life of an overlay against the reflection cracking. Generally, glass grid is more effective in reinforced overlay than polyester grid. Effect of crack width of the existing layer is significant when its magnitude increases from 6 to 9 mm.展开更多
Based on the crack tip field expansion of the Reissner plate, a special high order bending crack tip element is developed, and the element stiffness matrix is given in the explicit form, which is especially convenien...Based on the crack tip field expansion of the Reissner plate, a special high order bending crack tip element is developed, and the element stiffness matrix is given in the explicit form, which is especially convenient for engineering analyses. A numerical example is presented and compared with previous results to demonstrate the efficiency and accuracy of the special element.展开更多
文摘In order to study the mechanical properties of damaged reinforced concrete(RC)beams reinforced with ultra-high-performance concrete(UHPC),a four-point bending test was conducted to systematically investigate the influence of factors such as the number of reinforcement surfaces and the degree of damage.The results indicate that single-sided repaired beams have certain advantages in crack resistance performance,but are more disadvantageous in ultimate bearing capacity,with obvious debonding phenomenon before the end of loading.Compared with single-sided reinforcement,the cracking load of the three-sided reinforced beam increased by an average of 1.85 times,the ultimate bearing capacity increased by an average of 177.5%,and a good UHPC-RC combination effect could be formed,which could work synergistically until the end of loading.The degree of pre damage has a significant impact on the crack resistance performance of reinforced beams,while its impact on the ultimate bearing capacity is relatively limited.When the pre splitting width of the RC beam increases from 0.2 mm to 0.4 mm,the ultimate bearing capacity decreases by 28.33%.
文摘The contribution of chemical compositions in terms of carbon equivalent value（CEV） on impending crack propagation during weld bead bend tests（WBBTs） was studied with five different high-strength lowalloy steel plates that underwent different rolling processes. The test showed that cracks developed at the weld joint, easily passed through the coarse-grain heat-affected zone（CGHAZ）, and finally were arrested within the heat-affected zone（HAZ）. An apparent decrease in the average crack length, which consequently indicated improvement in crack arrestability, was found with decreasing CEV. In addition,the relatively fine microstructure in the HAZ of low-CEV steel plates helped in preventing the crack from further propagation. Special emphasis was placed on the empirical expectation of critical CEV above which WBBT might fail.
文摘The influence of the most important parameters on the service life of reinforced asphalt overlay with geogrid materials in bending mode was examined by employing the Taguchi method and analysis of variance techniques. The objectives of this experiment was to investigate the effects of grid stiffness, tensile strength, coating type, amount of tack coat, overlay thickness, crack width and stiffnesses of asphalt overlay and existing asphalt concrete on propagation of the reflection cracking. Results indicate that the stiffnesses of cracked layer and overlay are the main significant factors that can directly improve the service life of an overlay against the reflection cracking. Generally, glass grid is more effective in reinforced overlay than polyester grid. Effect of crack width of the existing layer is significant when its magnitude increases from 6 to 9 mm.
文摘Based on the crack tip field expansion of the Reissner plate, a special high order bending crack tip element is developed, and the element stiffness matrix is given in the explicit form, which is especially convenient for engineering analyses. A numerical example is presented and compared with previous results to demonstrate the efficiency and accuracy of the special element.
