Experimental and numerical analysis on interface damage of slab track under freeze-thaw cycles
The interface of slab track laid in cold regions is prone to debonding under the coupling of freeze-thaw cycles and temperature loads.Based on the composite specimen tests,the parameters of cohesive zone model were obtained and used in a simulation model of CRTS Ⅲ prefabricated slab track to study the interlayer damage.The results show that 1)the digital image correlation(DIC)technique can accurately capture the strain field changes on the interface of composite specimens under splitting and shear loading;2)when the temperature gradient is-40 ℃/m-60 ℃/m,the interface damage of the slab track is minimal and presents different patterns of expansion under positive and negative temperature gradients,each corresponding to damage of the cohesive element dominated by shear stress and normal tensile stress,respectively;3)the reduction of the elastic modulus at the concrete base after freeze-thaw inhibits interface damage and leads to a higher starting temperature gradient load,but cracking can occur on the concrete base after 150 freeze-thaws.For this reason,in the light of damage control of both the interface and concrete base,the elastic modulus of the concrete base is 54％or over that without freeze-thaw cycles.
CRTS Ⅲ prefabricated slab trackfreeze-thaw cyclebonding performancecohesive zone modelinterface damage
任娟娟、杜威、叶文龙、许雪山、邓世杰
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School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China
Key Laboratory of High-speed Railway Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China
China Railway First Survey and Design Institute Group Co.,Ltd.,Xi'an 710043,China
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