Analysis of Bending Characteristics of Carbonized Reconstituted Bamboo Sleepers Based on Digital Image Correlation Technology
Reconstituted bamboo has negative carbon properties and great potential to replace traditional material sleepers after carbonization.However,research on reconstituted bamboo sleepers lacks full-scale testing.This article designed carbonized reconstituted bamboo sleepers bonded with two different thickness arrangements,and used Digital Image Correlation(DIC)technology to study the deflection,crack characteristics and failure modes of bamboo sleepers under three-point and four-point bending tests.The results show that the ultimate bearing capacity of carbonized reconstituted bamboo sleepers can reach up to 292.445 kN(three-point bending test)and 414.525 kN(four-point bending test),which is much higher than that of concrete sleepers and wooden sleepers.The bending stiffness and ductility are between those of concrete sleepers and wooden sleepers.The thickness arrangements method has little effect on the ultimate bearing capacity and failure mode of carbonized reconstituted bamboo sleepers,but it directly affects the interlayer cracks and fracture positions of the sleepers.Carbonized reconstituted bamboo sleepers are in an elastic state during the bending process,and fracture occurs after reaching the ultimate bearing capacity.The failure mode is interlayer shear failure along or near the bonding surface of the neutral layer.In the three-point bending test,the bamboo sleeper fractured along the direction of the main crack.In the four-point bending test,cracks fracture is along or near the neutral layer position in the cross-section of the sleeper.The ultimate bearing capacity,flexural stiffness,and ductility of carbonized reconstituted bamboo sleepers fully meet the design requirements of railway sleepers and can be applied to ballasted tracks on heavy haul railway and mixed passenger and freight railway.
万方数据
维普
