玻璃钢 Pub Date : 1999-08-01 DOI: 10.14359/5691

H. Toutanji, M. Saafi

引用次数: 6

Experimental Study of Shear Behavior of Continuous Beams Reinforced with Carbon Fiber Reinforced Polymer 碳纤维增强聚合物连续梁抗剪性能试验研究

玻璃钢 Pub Date : 1999-08-01 DOI: 10.14359/5620

A. G. Razaqpur, D. Mostofinejad

{"title":"Experimental Study of Shear Behavior of Continuous Beams Reinforced with Carbon Fiber Reinforced Polymer","authors":"A. G. Razaqpur, D. Mostofinejad","doi":"10.14359/5620","DOIUrl":"https://doi.org/10.14359/5620","url":null,"abstract":"Four 6.5 m long two span continuous beams were tested to investigate the feasibility of using FRP grids as shear reinforcement. The beams were longitudinally reinforced with equal amounts of CFRP reinforcement while transversely two beams were reinforced with steel stirrups and two with CFRP grids. The two spans of each beam had identical amount and disposition of reinforcement, and were symmetrically loaded with a point load at the center of each span. For the beams with steel stirrups, the so-called A(v)/s = 2.0 mm while for the ones with CFRP grade the equivalent quantity was 1.75 mm. The elastic modulus of the grid was half the elastic modulus of the steel. The beams were monotonically loaded to destruction and they all failed in flexure. Despite their lower shear reinforcement ratio, the beams with the CFRP grid performed as well as those with the steel stirrups. They actually failed at 10% higher load that the beams with steel stirrups. Strain values of up to 0.4% were increased in the grids. Recognizing the practical convenience of grid shear reinforcement over custom manufacturing of stirrups, and considering their satisfactory performance, as observed in the present testing program, the use of FRP grids as shear reinforcement is indeed feasible.","PeriodicalId":68258,"journal":{"name":"玻璃钢","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86908734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Study on Structural Performance of Reinforced Concrete Columns with Waist-High Walls Strengthened by Carbon Fiber Reinforced Plastic Sheets 碳纤维增强塑料板加固腰高壁钢筋混凝土柱结构性能研究

玻璃钢 Pub Date : 1999-08-01 DOI: 10.14359/5627

H. Nagai, T. Kanakubo, Y. Jinno, Y. Matsuzaki, S. Morita

{"title":"Study on Structural Performance of Reinforced Concrete Columns with Waist-High Walls Strengthened by Carbon Fiber Reinforced Plastic Sheets","authors":"H. Nagai, T. Kanakubo, Y. Jinno, Y. Matsuzaki, S. Morita","doi":"10.14359/5627","DOIUrl":"https://doi.org/10.14359/5627","url":null,"abstract":"This research aims on understanding the influence of the method using carbon fiber reinforced plastic (CFRP) sheets on the performance of 13 reinforced concrete columns with waist-high walls. Main parameters of the specimens include the thickness and height of the attached walls, axial load, and the amount of CFRP sheets. The strengthening method is done by wrapping the upper portion of the column with sheets in a closed form. Also, the waist-high walls are equipped with holes where the carbon fiber strands (CF-anchor) are inserted and anchored to the ends of the sheets attached only on the surface of the lower portion of the column. Test results show that there is a great improvement in the ductility of the shear-failure type specimens when strengthened with CFRP. Also with an increase in the amount of the sheets, the ductility is further enhanced. The specimens strengthened using CFRP with CF-anchor also show higher ductility than the specimen where only the upper column is strengthened. The bending and shear strengths of the columns with waist-high walls can be calculated by using effective column height h(e) considering the presence of the all portions.","PeriodicalId":68258,"journal":{"name":"玻璃钢","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76284763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Seismic Rehabilitation of Unreinforced Masonry Walls 非加固砌体墙的抗震修复

玻璃钢 Pub Date : 1999-08-01 DOI: 10.14359/5630

O. S. Marshal, S. Sweeney, J. Trovillion

{"title":"Seismic Rehabilitation of Unreinforced Masonry Walls","authors":"O. S. Marshal, S. Sweeney, J. Trovillion","doi":"10.14359/5630","DOIUrl":"https://doi.org/10.14359/5630","url":null,"abstract":"The U.S. Army Construction Engineering Research Laboratory, in partnership with the Composite Institute of the Society of Plastics Industry, Inc. and in support of the Army's facility seismic rehabilitation efforts, is investigating the applicability of fiber reinforced polymer (FRP) composite materials systems to strengthen unreinforced masonry (URM) walls. The end product of the research will be the design guidance and construction specifications necessary for the Army to use these materials systems. Much of the Army's inventory of facilities are usually either lightly reinforced or unreinforced. This structural system has been shown to perform poorly in past earthquakes and requires upgrading to ensure safety and mission operation during and after an earthquake. This research will develop procedures for the rehabilitation and/or upgrade of masonry walls using typical advanced composite materials systems. New 4-ft by 4-ft double width brick walls with FRP composite reinforcing applied to one face were constructed and will be tested. The shear performance of different widths and thicknesses of FRP composite applied across brick mortar joints of brick triplets, three brick high prisms with the center brick offset by half an inch, was also tested. Using FRP composites for seismic rehabilitation of URM walls show great potential. Triplet tests showed consistent strengthening of the mortar joints as a function of the width of the FRP composite overlay. With multiple layers of FRP applied, the shear strength of the mortar joints increased sufficiently to cause failure to occur via brick compression failures instead of via shear failure at the mortar joints.","PeriodicalId":68258,"journal":{"name":"玻璃钢","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79081527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 27

Bond Failure of Concrete Fiber Reinforced Polymer Plates at Inclined Cracks—Experiments and Fracture Mechanics Model 混凝土纤维增强聚合物板斜裂缝粘结破坏试验与断裂力学模型

玻璃钢 Pub Date : 1999-08-01 DOI: 10.14359/5638

U. Neubauer, F. S. Rostásy

{"title":"Bond Failure of Concrete Fiber Reinforced Polymer Plates at Inclined Cracks—Experiments and Fracture Mechanics Model","authors":"U. Neubauer, F. S. Rostásy","doi":"10.14359/5638","DOIUrl":"https://doi.org/10.14359/5638","url":null,"abstract":"Bond failure is mostly brittle and often occurs a few millimeters deep in the concrete. A fracture mechanics-based engineering model of bond strength for this failure type, derived from pure bond tests exists. In a beam vertical shear crack, mouth displacements can reduce bond strength by reducing the total fracture energy required to destroy the local bond. To quantify this effect, the shear crack mouth displacements have to be calculated, dependent on the acting forces, the geometry, the reinforcement and the material parameters of the beam. Then a mixed mode fracture mechanics approach is used to quantify the of bond strength due to simultaneous action of bending and shear. In most cases, bond strength reduction due to vertical shear crack displacement will range around 5-10%. In CFRP-plates another type of debonding failure, specific to fiber reinforced plastics was observed. Interlaminar failure in the plate, preferably occurring with higher-strength concrete is considered a mixed mode fracture problem and was investigated by simultaneous measurements of the Mode I and mode II displacements of the bond crack with electronic speckle pattern interferometry (ESPI). A fracture mechanics approach to a criterion for interlaminar plate failure was derived. According to this, a surface tensile strength of the concrete of more than 3,0 MPa cannot be taken advantage of in design, since interlaminar plate failure will then govern bond failure.","PeriodicalId":68258,"journal":{"name":"玻璃钢","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89775383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 118

玻璃钢 Pub Date : 1999-08-01 DOI: 10.14359/5675

A. Gerritse, L. Taerwe

引用次数: 2

Concrete Cover Delamination in Reinforced Concrete Beams Strengthened with Carbon Fiber Reinforced Polymer Sheets 碳纤维增强聚合物板加固钢筋混凝土梁的混凝土覆盖层分层

玻璃钢 Pub Date : 1999-08-01 DOI: 10.14359/5667

G. Tumialan, P. Serra, A. Nanni, A. Belarbi

引用次数: 44

Japanese State of the Art on Seismic Retrofit by Fiber Wrapping for Building Structures: Technologies and Research and Development Activities 日本建筑结构纤维包覆抗震加固技术现状:技术和研发活动

玻璃钢 Pub Date : 1999-08-01 DOI: 10.14359/5678

H. Katsumata, K. Kobayashi, S. Morita, Y. Matsuzaki

{"title":"Japanese State of the Art on Seismic Retrofit by Fiber Wrapping for Building Structures: Technologies and Research and Development Activities","authors":"H. Katsumata, K. Kobayashi, S. Morita, Y. Matsuzaki","doi":"10.14359/5678","DOIUrl":"https://doi.org/10.14359/5678","url":null,"abstract":"Since the 1995 Hansin Earthquake, need of seismic retrofitting of existing structures has been strongly understood. Being expected to reduce inconvenience in retrofit work of buildings, some techniques using carbon and/or aramid fibers have been widely employed in Japan due to lightweight, flexibility, non-welding, and easy handling. Many of these techniques aim to improve shear capacity and ductility of existing reinforced concrete columns and may be called \"Standard Method\" due to the almost common working procedure. The procedure includes (1) wrapping columns in the transverse direction using continuous fiber sheets, (2) impregnating epoxy resin into the sheets to make FRP composite, and (3) doing surface treatment or arrangement of concrete to prevent voids or wrinkles. This \"Standard Method\" of fiber wrapping has induced development of other methods that improve a working process or can be applied for other structural members. In the future, the fiber wrapping technique will be more spread, however, it requires an approved and common quality control method. An education program for retrofit engineers and craftsmen should be also established.","PeriodicalId":68258,"journal":{"name":"玻璃钢","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78493829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Development of New Repair and Maintenance Technique with Carbon Fiber Reinforced Polymer Composite 碳纤维增强聚合物复合材料维修新技术的发展

玻璃钢 Pub Date : 1999-08-01 DOI: 10.14359/5658

T. Ando, E. Sawada, K. Nii

{"title":"Development of New Repair and Maintenance Technique with Carbon Fiber Reinforced Polymer Composite","authors":"T. Ando, E. Sawada, K. Nii","doi":"10.14359/5658","DOIUrl":"https://doi.org/10.14359/5658","url":null,"abstract":"New repair and maintenance techniques for existing reinforced concrete structures has been developed as a result of a marriage of corrosion prevention and carbon fiber reinforced polymer (CFRP) installation techniques. Rebar corrosion prevention is basically provided by penetration liquid and/or mortar, while mechanical degradation is compensated by CFRP. CFRP can also provide an effective layer for subsequent corrosive agent penetration. The technique can overcome various drawbacks of the current repair techniques by minimizing repair time and unnecessary chipping of damaged concrete, and protect degrading concrete structures. Such excellent performances have been proven by a series of experiments. Steel rebar embedded in a concrete block brushed with lithium nitrate-based penetrating corrosion inhibitor has been proven rust-free for years. The tensile strength of CFRP sheet have been proven unchanged after the exposure of 10,000 hours of accelerated weathering conditions. The CFRP sheet has also been proven impermeable to salt ion and water by experiments. Both shear and tensile strengths of concrete columns, damaged by salt penetration and then repaired with this new technique, have been proven equal or greater than the original strengths of control column.","PeriodicalId":68258,"journal":{"name":"玻璃钢","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78536651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Failure of Over-Reinforced Hybrid Fiber Reinforced Polymer Concrete Beam Columns 超配筋混杂纤维增强聚合物混凝土梁柱破坏

玻璃钢 Pub Date : 1999-08-01 DOI: 10.14359/5616

A. Mirmiran, M. Shahawy, C. Khoury

引用次数: 2

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