Experimental Study and Numerical Analysis of Hybrid Fiber Reinforced Self-Compacting Concrete Segments at High Temperatures
To study the preloading on the mechanical properties of hybrid fiber self-compacting concrete segments at high-temperatures,high-temperature tests were conducted on five segments to obtain the seg-ment furnace temperature,concrete temperature,deformation,and failure mode.A calculation subroutine was developed based on ABAQUS software to establish a temperature field and mechanical analysis model for hybrid reinforced fiber self-compacting concrete segments.The appropriate constitutive relations during the different stages were selected,and the influence of explict or implicit transient thermal strain and pre-load on segment displacement and equivalent plastic tensile strain was analyzed.The results showed that as the preload increased,the number of cracks on the side of the segment increased and the length became smaller,the number of cracks on the outer arc surface decreased,the distribution of cracks on the inner arc surface became more uniform,and the addition of fibers was helpful to reduce the average crack spacing and the high temperature damage of concrete at the arch foot of segment.The transient thermal strain had an important influence on the equivalent plastic tensile strain distribution of the segment during the cooling stage.When the explicit transient thermal strain was used,the equivalent plastic tensile strain distribution of the segment was more consistent with the test crack area.
tunnel segmentshybrid fibershigh temperature testpreloadingtransient thermal strain
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