Experimental Study On Interfacial Bonding Performance Of PCM Reinforced Concrete

Compared with the traditional strengthening technology,reinforce and repair the polymer cement mortar(PCM)in English have the advantages of the fit is good,construction is convenient,but hot and humid environment PCM and concrete interface bonding performance degradation easily,especially the interface performance of concrete after high temperature damage reinforcement is still not clear,so this article through to the size is 100 mm*100 mm*100 mm block preprocessing and splitting tensile test,studied the different moisture content,interface treatment,PCM reinforcement material affect the performance of PCM reinforced concrete interface bonding,It is revealed that the interface performance of PCM reinforced high temperature damaged concrete is subject to the degradation rule of different water content,and the interface bonding performance is improved by considering the influence of interface strengthening materials and temperature.The main research conclusions are as follows:(1)the interfacial bonding strength decreased with the increase of interfacial moisture content.The pcm1-0.5 specimen moisture content increased from 50%to 75%and 100%,and the interfacial bonding strength decreased by 18.89%and 38.25%,respectively.The strength of PCM and concrete also had a certain influence on the interfacial bonding performance.The water-cement ratio increased from 0.3 to 0.7.The interfacial strength of pcml-concrete composite specimens and pcm2-concrete composite specimens decreased by 24.84%and 13.06%respectively.Four different interface treatment:chisel,corrugated grinding,sandblasting,wire wheel is obviously different from the interface roughness,respectively 500,80,50,190 microns,the increase of roughness can improve the interface bonding strength,but strength is affected by the influence of interface damage(such as cut hair),four kinds of interface treatment,wire wheel processing mode of interface bond properties is best.(2)the high temperature damage of concrete has a great influence on the interfacial bonding performance of the reinforced specimens.Compared with the interface strengthened by ordinary concrete,the interfacial bonding strength of concrete specimens with water cement ratios of 0.3,0.5 and 0.7 decreased by 20.47%,33.33%and 33.45%respectively after the specimens were subjected to a high temperature of 600℃.At the same time,the increase of the interfacial moisture content of the high-temperature damaged concrete strengthened by PCM will also reduce the interfacial bond strength.With the increase of the damage temperature,the weakening effect is gradually obvious.The moisture content of the pcm2-0.5 specimen rises from 50%to 100%.The above results show that the interface bonding performance of the reinforcement is mainly affected by the degradation of PCM and the properties of concrete materials.In combination with the existing studies,an interface bonding performance evaluation model of the interface bonding performance under the combined effects of high temperature damage and moisture content is established in this paper.The calculated results of the model are in good agreement with the test results.(3)based on the above results,a layer of epoxy resin(EP)or high-performance carbon fiber material(CFRP)was added to the interface in this paper to enhance the bonding performance.EP and CFRP strengthened specimens are 20.30%and 50.18%stronger than those without interface reinforced materials.Splitting tensile strength of the specimens and decreased with the increase of temperature,after dealing with the temperature of 100℃,and the interface strengthening material specimen,EP reinforced specimen,CFRP strengthening interface splitting tensile strength of the specimens is interesting fell by 35.42%,58.90%and 63.39%,respectively,when the environment temperature higher than 80℃,for reinforced using CFRP or EP are detrimental to the ascent of the interface bonding performance;The relationship between the splitting strength and the temperature of the three types of specimens was fitted by function.The splitting strength changed linearly with the increase of temperature.