Study On The Tensile Properties Of Carbon Textile Reinforced Mortar Composite Plates Based On The Influence Of Temperature

Carbon Textile reinforced mortar(CTRM),which combines the carbon textile and high–performance mortar,is a composite characterized by high strength,light weight and high durability.In the engineering application area,CTRM has a broad and bright prospect.At present,experimental research on the mechanical properties of CTRM based on the temperature effect is still in its infancy.In order to obtain relevant theories as well as to promote the application of CTRM,an in–depth research on its mechanical properties based on the temperature effect is essential.In this paper,the effects of temperature,heating path,steel fibers in the matrix and pre–tension on the textile on the tensile properties of CTRM plates were studied by uniaxial tensile test.The following results are obtained:1.Results obtained by the uniaxial tensile tests of CTRM specimens without steel fibers in the matrix nor pre–tension on the textile show that,when the target temperature is greater than 20?,CTRM specimens in residual tests have a dependable interfacial bonding and no debonding phenomenon,and is equipped with the strain hardening ability;in comparison,CTRM specimens in thermo–mechanical tests have lower stress at the same strain level and less number of cracks,and the textile–matrix interface is debonded.When the target temperature increases,the cracking stress,ultimate stress,ultimate strain and pre–cracking elastic modulus of the CTRM specimens in thermo–mechanical tests gradually reduces;as for CTRM specimens in residual tests,the pre–cracking elastic modulus gradually decreases with increasing target temperature,while the ultimate stress,ultimate strain and cracking stress all fluctuate at 100? and 150?.The CTRM specimens in thermo–mechanical tests are still equipped with the strain hardening ability.2.Results obtained by the thermo–mechanical tensile tests show that,as the experimental temperature rises,the number of cracks in all tested CTRM specimens reduces and the energy dissipation capability decreases gradually.As the target temperature exceeds 20?,the failure modes of the CTRM specimens with single steel fibers effect or pre–tension effect,as well as the specimens with no steel fibers nor pre–tension,is manifested as debonding between the textile and the matrix.Only when the steel fibers in matrix and the pre–tension on textile are combined,debonding between the textile and the matrix of the CTRM specimens occurs at 100?,150? and 200?.3.Results obtained by the thermo–mechanical tensile tests show that,the tensile responses of CTRM specimens decrease with the increase of target temperatures,and the corresponding tensile properties of CTRM specimens are weakened,which can be enhanced by adding steel fibers to the matrix and/or applying pre–tension to the textile.When the temperature rises,the pre–tension effect on the thermo–mechanical crack resistance of CTRM specimens is greater than that of the steel fibers.The effect of the steel fibers on the thermo–mechanical tensile strength of CTRM specimens is greater than the pre–tension effect at 60?and 100?,but less than the pre–tension effect at 100? and 150?.The combination of steel fibers and pre–tension can improve all the tensile properties of CTRM specimen in thermo–mechanical tests,which is more significant compared with the CTRM specimens under the single effect of steel fibers or pre–tension,except for the deformability.