【作者】 王川；

【导师】 欧进萍；

【作者基本信息】 哈尔滨工业大学 ， 力学， 2009， 博士

【摘要】 FRP(Fibre Reinforced Polymer)材料以其诸如轻质、高强和高耐久性等优点赢得了土木工程科研人员的青睐。但目前,土木工程结构中不论是对结构进行加固还是增强所使用的FRP筋、板等材料都是采用热固性FRP材料(FRSP,Fiber Reinforced Thermosetting Polymer)。FRSP存在整体柔韧性较差、破坏没有预兆、同时存在污染环境,不能二次回收等问题。再者,FRSP材料不具有二次成型的特点,使得结构中许多特殊形式不易实现,如弯筋或箍筋等。同时,FRSP不论是筋还是板多为预制使用,在现场基本没有再加工能力。针对FRSP材料的这些不足,本文基于FRP的另外一种体系——热塑性FRP材料(FRTP,Fiber Reinforced Thermoplastic Polymer),开发了玻璃纤维增强聚丙烯(GFRPP,Glass Fiber Reinforced Polypropylene)筋。对其生产工艺、物理及力学性能、耐久性能和折弯工艺等进行了系统的研究。同时,在充分研究了GFRPP筋及其树脂基体性能的基础上,我们还开发出GFRPP-OFBG(Optical Fiber Bragg Grating)智能筋以及适用于沥青路面应变监测的PP-OFBG应变传感器,并进行了实验验证和工程应用。本文主要研究内容如下:首先,对GFRPP筋的生产工艺进行了研究。对增强纤维与树脂熔体的浸渍过程进行了理论分析,确定了合适的浸渍工艺;同时通过制品性能和生产工艺要求确定了纤维与树脂在制品中的含量,确定了混合树脂各组分配比;并采用自行研制的在线熔融浸渍的热塑性拉挤工艺装置,以及热塑性拉挤缠绕、热塑性拉挤模压装置生产出光面GFRPP筋和带肋GFRPP筋,同时确定了生产工艺参数并研究了生产工艺参数对制品性能的影响,并对GFRPP筋制品的表面及内部缺陷进行了分析。其次,对自行研制生产的不同树脂及纤维配比和表面形式的GFRPP筋分别进行了拉伸强度、拉伸模量、层间剪切强度、冲击韧性以及吸水率等物理及力学性能的测试,并与热固性FRP筋进行对比研究。针对GFRPP筋径向强度低,拉伸实验时容易被实验机夹具破坏的特点,通过ANSYS有限元分析,设计出了适合于试验应用的锚夹具。再次,对自行研制的GFRPP筋进行了折弯理论的分析,并研究了GFRPP筋折成弯筋或箍筋的具体工艺;根据GFRPP筋的折弯条件开发研制出结构简单、适合于GFRPP筋折弯的弯曲机。同时对弯曲后的GFRPP筋进行了混凝土粘结性能试验和采用GFRPP作为箍筋的加筋混凝土梁受弯实验,以此来讨论GFRPP作为弯筋和箍筋是否满足土木工程需要。第四,对自行研制的GFRPP筋进行了在20℃和60℃条件下的碱溶液以及60℃条件下酸和盐溶液中的耐久性常规和加速试验对比研究以及紫外光快速老化试验研究。通过对试件的拉伸强度、拉伸模量、抗冲击性以及层间剪切强度等性能的试验研究,讨论了GFRPP筋耐环境腐蚀性能。并采用FHWA法对GFRPP筋在10℃,100%RH环境中的耐久性寿命进行预测。同时,通过进行GFRPP筋紫外光加速老化试验研究,对不同炭黑含量的GFRPP筋以及热固性FRP筋进行了对比研究,通过对其冲击韧性和层间剪切强度进行对比试验,讨论了炭黑的掺入对制品耐紫外光老化性能的影响。第五,在GFRPP筋的拉挤生产过程中,我们通过复合OFBG的方法研制了GFRPP-OFBG智能筋,并对其力学性能和感知性能进行了试验研究,同时利用双光栅法对GFRPP筋拉挤成型过程中的温度和应变进行在线监测,对GFRPP筋拉挤工艺过程控制参数提供参考,同时也检测了智能筋成型工艺对其中光栅性能的影响。同时我们利用PP基体采用挤出生产工艺封装制造了PP-OFBG传感元件,并对其进行了传感性能的试验研究,同时采用双光栅法两次测量对其成型过程中的温度及应变变化进行了在线监测,讨论了采用此工艺来研制大应变传感器的问题。最后,基于PP-OFBG传感元件,同时通过设计PP树脂基体模量与沥青混凝土模量相当,本文研制开发出主要针对于沥青路面应变监测的PP-OFBG埋入式应变传感器,并进行了传感性能试验研究。通过进行沥青混凝土梁的四点弯曲静载及动载试验并与理论计算进行了对比研究,我们发现这种传感器能够很好地反映出沥青混凝土的变形特征。通过采用PP-OFBG埋入式传感器对钢梁沥青路面结构进行了实际监测方案的设计、监测和分析研究证明了PP-OFBG作为沥青路面变形测试具有良好、稳定的特性,能够满足实际路面测试要求。更多还原

【Abstract】 FRP (Fiber Reinforced Polymer) materials have gained much more interests of the researchers in civil engineering for their light weight, high strength and excellent durability performance. While, as we know, common FRP rebars or plates used for reinforcing or strengthening in civil engineering are mostly made by fiber reinforced thermosetting polymer (FRSP) materials. But FRSP have so many disadvantages such as: poor integral flexibility, no premonition before break, environment pollution and so on. Further more, FRSP materials can not be reshaped so that many of the special shapes as bending rebar or hoop rebar cannot be easily obtained. Rebars or plates are mostly prefabricated in factory, and they can not be handled at site. For above reasons, we developed and successfully fabricated Glass Fiber Reinforced Polypropylene(GFRPP) according to another FRP system—Fiber Reinforced Thermoplastic Polymer (FRTP). And the fabricating techniques, physical and mechanical performance, durability and bending techniques have been systematically studied. Meanwhile, we have also invented and produced GFRPP-OFBG composite rebar and PP-OFBG strain sensor for asphalt pavement strain monitoring on the base of good understanding on the performance of the GFRPP rebar and resin matrix, experiments and project application have been performed. The main works of this dissertation are as follows.Above all, the fabricating techniques of GFRPP rebar have been studied. And theoretical analysis on the impregnation of fibers and molten resin has been done, the appropriate impregnation techniques have been defined; the fiber and resin contents and resin mixture ratio have also determined under the needs of fabricating process and performance of the products. Round and ribbed GFRPP rebar have been successfully fabricated through ourselves-designed online molten impregnation thermoplastic pultrusion equipments and thermoplastic pultrusion-enwinding techniques or thermoplastic pultrusion-molding techniques. And the processing parameters have been defined, and their effects on the performance of the products have been studied. Some defects inside or outside of GFRPP rebars have been analyzed.Secondly, some physical and mechanical performance of GFRPP rebars with different surface-treatment and fiber/resin mixture ratio as tension strength, tension modulus, interlamination shearing strength, impact toughness and hygroscopic coefficient have been tested, and some comparison study have been done to those of fiber reinforced thermosetting polymer rebars. As we know, the radial strength of FRP rebar is very low, and it can be easily broken by the holders of the testing machine when being tensioned. Because of these, we did some finite element method (FEM) analysis by ANSYS software on the anchors of FRP rebars, and a kind of proper anchor have been designed and fabricated.Thirdly, bending theoretical analysis on GFRPP rebars have been performed and the specific techniques on making GFRPP bending rebar or GFRPP hoop rebar have been studied; and we also invented and produced a simple and flexible“GFRPP rebar bending machine”according to the performance of GFRPP rebar. And it was experimentally studied bonding performance of some kinds of bent rebar with concrete bonding specimens so that we can know whether bent GFRPP rebar can meet the needs of civil engineering. Results shows that the strength in bending part of GFRPP rebar can reach 30%~60% of the ultimate tension strength, and with the strengthening of epoxy resin, this strength can reach or above 70% of the ultimate tension strength.Fourthly, to study the corrosion resistance problem of GFRPP rebar, corrosion tests of GFRPP rebars have been done in alkali solution individually at 20, and 60℃accelerating temperature and in salt and acid solution at 60℃accelerating temperature. Some UV-light accelerating ageing experiments also have been done to test the UV-light resistance of GFRPP rebars. The physical and mechanical performance such as tension strength, tension modulus, interlamination shearing strength, impact toughness and hygroscopic coefficient have been tested to evaluate the corrosion or UV-light ageing abilities. Durability life of the GFRPP rebars serving in 10℃, RH=100%, without stress condition was predicted individually by tow kinds of FHWA methods. Also, UV-light accelerating ageing experiments have been done to test the effects of carbon content on the UV-light resistance of GFRPP rebars, and the interlamination shearing strength, impact toughness have been tested at different age. The results tells that carbon as a light stabilizer can improve the UV-light resistance of GFRPP rebars, so it can help to prolong the period of storage and service.Fifthly, we successfully fabricated GFRPP-OFBG composite rebar by embedding bare OFBG into GFRPP rebar during pultrusion process, and also the mechanical and sensitive properties have been studied.“Tow OFBG method”was used in monitoring the inner strain and temperature of GFRPP rebar when producing GFRPP rebar with thermoplastic pultrusion techniques, which can give reference on deciding the processing parameters. And also, we packaged bare OFBG with PP resin by extrusion techniques; the sensitive property of PP-OFBG was excellent. Online monitoring work with“Tow OFBG method”has been done to measure the inner strain and temperature changes of PP-OFBG during extrusion process. Based on these, large-scale strain measuring sensor was discussed.Finally, based on the PP-OFBG sensing element above, we developed a novel PP-OFBG strain sensor special for asphalt pavement strain measuring because of the same modulus of PP resin and asphalt concrete. Its sensitive property was tested, and 3 asphalt concrete beams were prepared for four point bending experiments. Through comparing the theoretical calculation and static and dynamic loading tests, we found that this novel PP-OFBG strain sensor can reflect the deformation of asphalt concrete well. We also cooperated finishing a steel-asphalt girder deformation monitoring experiment, 90 sensors were embedded or welded. Through designing, monitoring and analyzing we found that as asphalt pavement measuring sensor, PP-OFBG can give stable and accurate results, which can meet the needs of asphalt pavement strain measuring well.更多还原