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结构新型热固性FRP复合筋及其性能

Thermosetting FRP Composited Rebars and Their Performance for Civil Infrastructures

【作者】 张志春

【导师】 欧进萍;

【作者基本信息】 哈尔滨工业大学 , 工程力学, 2008, 博士

【摘要】 FRP(Fibre Reinforced Polymer)筋以其轻质、高强尤其是优异的耐久性而成为一些土木工程结构中钢筋的替代品。本文针对FRP筋在土木工程结构中的应用问题,研制了带肋FRP筋制作装置,研究制作了钢绞线-GFRP(SGFRP)复合筋,带肋FRP筋和BFRP筋等一系列新型FRP筋,对其中主要类型的FRP筋粘结性能、耐久性以及与光纤光栅复合的智能特性等进行了系统研究,主要研究内容如下:1.新型FRP复合筋的研制及基本性能研究。针对FRP筋在土木工程结构应用中存在的模量低、成本高和耐久性问题,分别发明和研制了钢绞线-GFRP(SGFRP)复合筋与玄武岩纤维FRP(BFRP)筋,并对其力学性能和耐久性进行了试验研究。研究结果表明:SGFRP筋与GFRP筋相比抗拉弹性模量可以提高50%以上,而且SGFRP筋在酸、碱和盐溶液中具有很好的耐久性;BFRP筋的抗拉性能与GFRP筋相当,但是在碱、酸和盐溶液中的耐久性较GFRP筋要差,尤其是在碱溶液中,其主要原因是玄武岩纤维表面硅烷耦联剂水解。研制了拉缠带肋FRP筋制作装置和成型工艺,对FRP筋肋形式和肋间距进行了定型研究,并制作了各种带肋FRP筋。研究确定的带肋FRP筋最佳肋形式和参数为:螺距为1倍直径的反向双螺旋纤维束缠绕肋。2.磁场固化拉挤GFRP筋力学与耐久性能。根据磁场对树脂的改性作用,对FRP拉挤成型工艺设备进行改进,研究开发了FRP筋磁场固化拉挤工艺;研究了成型磁场强度对成型后GFRP筋力学性能的影响,确定了最佳磁场强度;对最佳磁场强度成型和无磁场成型GFRP筋进行80℃水中的耐久性对比试验,以吸水率和层间剪切强度为指标,研究了磁场固化工艺对GFRP筋耐久性的影响。试验结果表明:磁场固化可以提高GFRP筋的层间剪切强度、抗压强度和在水中的耐久性。3. FRP筋与混凝土的粘结性能及其多种因素的影响。试验研究了温度处理、腐蚀环境和恒载作用对带肋GFRP和SGFRP筋与混凝土粘结性能影响。首先分别试验研究了70℃处理200小时后,70℃下和-30℃下三种温度环境中两种Φ8mm FRP筋和Φ12mm钢筋与混凝土的粘结性能;其次试验研究了两种FRP筋与混凝土试样经过60℃下碱溶液为期1、2和3.5个月浸泡后的粘结性能,分析了碱腐蚀环境对FRP筋与混凝土粘结性能的影响;最后试验研究了两种FRP筋分别在60%和75%最大粘结荷载作用下的恒载粘结性能,分析了恒载作用对FRP筋与混凝土粘结性能的影响。4. FRP筋的耐久性寿命预测。针对GFRP筋耐碱性问题,对光面和带肋GFRP筋利用34、60和80℃加速温度进行碱溶液中浸泡试验,分析了两种GFRP筋在碱溶液中不同温度下拉伸性能与浸泡时间关系,利用TSF法和FHWA法对两种GFRP筋在10℃、100%RH混凝土环境中的耐久性寿命进行预测;对Φ8mm带肋和Φ7mm光面SGFRP筋进行60℃下碱、酸和盐溶液浸泡试验,分析了两种SGFRP筋在各种腐蚀溶液中的耐腐蚀性能。预测结果表明:光面GFRP筋的耐久性寿命为带肋GFRP筋的4倍左右。5. FRP-OFBG智能筋成型过程的残余应变及其对传感特性的影响。针对单向FRP筋轴向残余应变问题,从理论上分析了智能筋制作过程对其中各组分引起的残余应变,利用双光栅法对GFRP筋拉挤成型过程中的温度和应变进行了在线监测;分析了恒载和常温无应力作用对智能筋中光栅残余应变的影响,研究了智能筋的传感稳定性问题;分析了智能筋中光栅光谱劣化产生原因,提出了高温后处理对智能筋中光栅双峰和多峰现象改善的方法。

【Abstract】 FRP(Fibre Reinforced Polymer)rebar becomes the substitution of steel rebar in some civil infrastructures, for its light weight, high strength and especially excellent durability performance. Against the problems of applying FRP rebar in civil infrastructures, this dissertation develops ribbed FRP rebar fabrication devices, and fabricates a series of new style of FRP rebars, such as steel cable-GFRP (SGFRP) composited rebar, ribbed FRP rebar and BFRP rebar. To the main type of FRP rebars this dissertation systematically studies bonding performance, durability and intelligent properties composited with FBG. Main works of this dissertation are followed as:1. New types of FRP composited rebar development and their basic properties. Against low modulus, high price and durability problem of FRP rebar applied in civil infrastructures, this dissertation individually invented and developed steel cable-GFRP (SGFRP) composited rebar and basalt fibre FRP (BFRP) rebar, and done experimental investigation of their mechanical and durability performances. The results indicate that SGFRP rebars produce more than 50% modulus improvement comparing to GFRP rebar, and exhibit good durability performances in acid, alkali and saline solution; BFRP rebars show equivalence tensile properties to GFRP rebars, but bad durability performances in acid, alkali and salt solution, especially in alkali solution. The durability performance of BFRP rebar is caused by hydrolyzation of silane coupling agent on the surface of basalt fibre; To improve bonding performance of FRP rebar with concrete, this dissertation developed pull-winding ribbed FRP rebar fabrication devices and fabrication process, done rib style and spacing standardized test, and fabricated diverse of ribbed FRP rebars. The rib standardized test result defines that optimal rib of ribbed FRP rebar is fibre bundle inverse double winding with 1 time diameter pitch.2. Mechanical and durability performances of magnetism curing pultrusion GFRP rebar. According to modifying effect of magnetic field to resin, through modification of FRP pultrusion process and equipments, this dissertation developed FRP rebar magnetism curing pultrusion process, studied the effect of fabrication magnetic field intensity on mechanical performances of fabricated GFRP rebar, and confined the optimal intensity of curing magnetic field. Through durability contrast test of GFRP rebars fabricated with optimal curing magnetism intensity and without magnetic field in 80℃water, according to water-absorbing capacity and interlaminate shear strength, the effect of magnetism curing on the durability performance of GFRP rebar was studied. Experimental results show that magnetism curing can improve GFRP rebar interlaminate shear strength, compression strength and durability in water.3. Bonding performance of FRP rebars with concrete and multi-factor influence. Temperature disposal, corrosion environment and sustained load action effects on bonding performance of ribbed GFRP and SGFRP rebars with concrete were studied. Firstly, it was experimentally studied the bonding performance of two kindsΦ8mm FRP rebar andΦ12mm steel rebar with concrete individually under 70℃, -30℃and after 200 hours of 70℃treatment three kinds of temperature condition; Next it was experimentally studied bonding performance of two kinds FRP rebar with concrete bonding specimen in 60℃alkali solution individually after 1, 2 and 3.5 months of soaking, which analyzes the effect of alkali environment on the bonding performance of FRP rebar with concrete; Finally it was experimentally studied sustained load bonding performance of two kinds of FRP rebars with concrete under 60% and 75% of maximum bonding load, which analyzes the effect of sustained load on bonding performance of FRP rebar with concrete.4. FRP rebar durability life predictions. Against the alkali resistance problem of GFRP rebar, corrosion tests of round and ribbed GFRP rebars were done in alkali solution individually in 34, 60 and 80℃accelerating temperature. Relation of tensile performances and corrosion time of two kinds GFRP rebar under different temperatures was analyzed, and durability life of two kinds GFRP rebar serving in 10℃, RH=100% concrete, without stress condition was predicted individually by TSF and FHWA method; According to the corrosion test ofΦ8mm ribbed andΦ7mm round SGFRP rebars in 60℃acid, alkali and salt solution, it was analyzed two kinds SGFRP rebar corrosion resistant property in various corrosion solutions. Durability life prediction results show that durability life of round GFRP rebar is about 4 times of ribbed GFRP rebar’s. 5. Residual stain of FRP-OFBG smart rebar in fabrication process and its effect on smart rebar sensing character. Against axial residual strain in unidirectional FRP rebar, it was theoretically analyzed residual strain of various constituents introduced in smart rebar fabrication process. Utilizing double FBGs method, the temperature and strain in GFRP rebar pultrusion fabrication process were on-line monitored. Through experimental analysis of sustained load and room temperature unstressing action influence on residual strain of smart rebar, sensing stability of smart rebar is studied. This dissertation analyzed deterioration reason of FBG spectrum in smart rebar, and introduced high temperature post treatment method to settle problem of double or multi peaks phenomenon of FBG in smart rebar.

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