检索结果-南通市图书馆

Preparation and Reinforcement Adaptability of Jute Fiber Reinforced Magnesium Phosphate Cement Based Composite Materials

引用

Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 999-1009页

作者：刘芯州郭远臣 WANG Rui XIANG Kai WANG Xue YE Qing College of Civil Engineering Chongqing Three Gorges UniversityChongqing 404100China

To improve the brittleness characteristics of magnesium phosphate cement-based materials(MPC)and to promote its promotion and application in the field of structural reinforcement and repair,this study aimed to increase the toughness of MPC by adding jute fiber,explore the effects of different amounts of jute fiber on the working and mechanical properties of MPC,and prepare jute fiber reinforced magnesium phosphate cement-based materials(JFRMPC)to reinforce damaged beams.The improvement effect of beam performance before and after reinforcement was compared,and the strengthening and toughening mechanisms of jute fiber on MPC were explored through microscopic analysis.The experimental results show that,as the content of jute fiber(JF)increases,the fluidity and setting time of MPC decrease continuously;When the content of jute fiber is 0.8%,the compressive strength,flexural strength,and bonding strength of MPC at 28 days reach their maximum values,which are increased by 18.0%,20.5%,and 22.6%compared to those of M0,respectively.The beam strengthened with JFRMPC can withstand greater deformation,with a deflection of 2.3 times that of the unreinforced beam at failure.The strain of the steel bar is greatly reduced,and the initial crack and failure loads of the reinforced beam are increased by 192.1%and 16.1%,respectively,compared to those of the unreinforced beam.The JF added to the MPC matrix dissipates energy through tensile fracture and debonding pull-out,slowing down stress concentration and inhibiting the free development of cracks in the matrix,enabling JFRMPC to exhibit higher strength and better toughness.The JF does not cause the hydration of MPC to generate new compounds but reduces the amount of hydration products generated.

关键词： magnesium phosphate cement jute fiber reinforcement of damaged beam flexural behavior

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

flexural behavior of high-strength,steel-reinforced,and prestressed concrete beams

引用

Frontiers of Structural and Civil Engineering 2021年第1期15卷 227-243页

作者： Qing JIANG Hanqin WANG Xun CHONG Yulong FENG Xianguo YE School of Civil and Hydraulic Engineering Hefei University of TechnologyHefei 230009China Anhui Key Laboratory of Civil Engineering and Materials Hefei 230009China College of Water Conservancy and Civil Engineering Xinjiang Agricultural UniversityUrumqi 830052China

To study the flexural behavior of prestressed concrete beams with high-strength steel reinforcement and high-strength concrete and improve the crack width calculation method for flexural components with such reinforcement and concrete,12 specimens were tested under static loading.The failure modes,flexural strength,ductility,and crack width of the specimens were analyzed.The results show that the failure mode of the test beams was similar to that of the beams with normal reinforced concrete.A brittle failure did not occur in the specimens.To further understand the working mechanism,the results of other experimental studies were collected and discussed.The results show that the normalized reinforcement ratio has a greater effect on the ductility than the concrete strength.The cracking-and peak-moment formulas in the code for the design of concrete(GB 50010-2010)applied to the beams were both found to be acceptable.However,the calculation results of the maximum crack width following GB 50010-2010 and EN 1992-1-1:2004 were considerably conservative.In the context of GB 50010-2010,a revised formula for the crack width is proposed with modifications to two major factors:the average crack spacing and an amplification coefficient of the maximum crack width to the average spacing.The mean value of the ratio of the maximum crack width among the 12 test results and the relative calculation results from the revised formula is 1.017,which is better than the calculation result from GB 50010-2010.Therefore,the new formula calculates the crack width more accurately in high-strength concrete and high-strength steel reinforcement members.Finally,finite element models were established using ADINA software and validated based on the test results.This study provides an important reference for the development of high-strength concrete and highstrength steel reinforcement structures.

关键词： high-strength steel reinforcement high-strength concrete flexural behavior crack width

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research on flexural behavior of Coral Aggregate Reinforced Concrete Beams

引用

China Ocean Engineering 2018年第5期32卷 593-604页

作者： MA Hai-yan DA Bo YU Hong-fa WU Zhang-yu Department of Civil Engineering Nanjing University of Aeronautics and Astronautics

Through the flexural behavior test of coral aggregate reinforced concrete beams(CARCB) and ordinary Portland reinforced concrete beams(OPRCB), and based on the parameters of concrete types, concrete strength grades and reinforcement ratios, the crack development, failure mode, midspan deflection and flexural capacity were studied, the relationships of bending moment-midspan deflection, load-longitudinal tensile reinforcement strain, load-maximum crack width were established, and a calculation model for the flexural capacity of CARCB was suggested. The results showed that with the increase in the reinforcement ratio and concrete strength grade, the crack bending moment(Mcr)and ultimate bending moment(Mu) of CARCB gradually increased. The characteristics of CARCB and OPRCB are basically the same. Furthermore, through increasing the concrete strength grade and reinforcement ratio, Mcr/Mu could be increased to delay the cracking of CARCB. As the load increased, crack width(w) would also increase. At the beginning of the loading, w increased slowly. And then it increased rapidly when the load reached to the ultimate load, which then led to beam failure. Meanwhile, with a comprehensive consideration of the effects of steel corrosion on the loss of steel section and the decrease of steel yield strength, a more reasonable calculation model for the flexural capacity of CARCB was proposed.

关键词： coral aggregate reinforced concrete beam flexural behavior steel corrosion reinforcement ratio concrete strength calculation model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Characterization of the flexural behavior of Bamboo Beams

引用

Journal of Renewable Materials 2021年第9期9卷 1571-1597页

作者： Limin Tian Jianpeng Wei Jiping Hao Qiushuo Wang School of Civil Engineering Shaanxi Key Laboratory of Structure and Earthquake ResistanceXi’an University of Architecture and TechnologyXi’an710055China The Key Laboratory of Plateau Building and Eco-Community in Qinghai Qinghai Building and Materials Research Co.Ltd.Xining810008China Anhui Province Key Laboratory of Green Building and Assembly Construction Anhui Institute of Building Research&DesignHefei230031China

Bamboo is a renewable and environmentally friendly material often used for construction.This study investigates the flexural behavior of bamboo beams through theoretical and finite element(FE)analyses.Considering the material’s nonlinearity,a method of calculating load-deflection curves is proposed and validated via FE analysis.The interfacial slippage dominated by the shear stiffness of the interface between two bamboo poles significantly influences the flexural behavior of double-pole bamboo beams.Thus,the load-deflection curves for different shear stiffnesses can be obtained via theoretical and FE analyses.Subsequently,a novel configuration using diagonal steel bands to avoid slippage is presented.An inclination angle of 45°is suggested to adequately develop the stiffness and bearing capacity of the steel band.

关键词： Bamboo beam flexural behavior interfacial slippage steel band FE analysis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Improvement of Cracking-resistance and flexural behavior of Cement-based Materials by Addition of Rubber Particles

引用

Journal of Wuhan University of Technology(Materials Science) 2008年第4期23卷 579-583页

作者： KANG Jingfu JIANG Yongqi School of Civil Engineering Tianjin University Tianjin 300072 China

By ring test and bend test, the improvement of waste tire rubber particles on the crack- resistance and flexural behaviors of cement-based materials were investigated. Test results show that the cracking time of the ring specimens can be retarded by the incorporation of rubber particles in the cement paste and mortar. The improvement in the crack-resistance depended on the rubber fraction. When the rubber fraction was 20% in volume, the cracking time was retarded about 15 h for the paste and 24 d for the mortar respectively. flexural properties were evaluated based on the bend test results for both mortar and concrete containing different amount of rubber particles. Test results show that rubberized mortar and concrete specimens exhibit ductile failure and significant deformation before fracture. The ultimate deformations of both mortar and concrete specimen increase more than 2-4 times than control specimens.

关键词： composite material rubberized concrete cracking-resistance flexural behavior

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Experimental Study on flexural behavior of Corroded Channel Steel Beams

引用

Journal of Donghua University(English Edition) 2015年第5期32卷 864-869页

作者：于峰武萍 School of Civil Engineering Anhui University of Technology

In order to study the mechanical behavior of corroded channel steel beam,experiment on five corroded channel steel beams is carried out. Test results show that the bending failures may occur under the ultimate load carrying capacity of members,compared with the calculating results of non-corrosion channel steel beam,and the bearing capacity of corroded channel steel beam is reduced,while the deflection is increased. With the increase of shear-span ratio,the bearing capacity of corroded channel steel beam reduces and the deflection increases gradually; with the increment of heightspan ratio, the bearing capacity increases and the deflection decreases gradually; with the enhancement of width-height ratio,the bearing capacity reduces and the deflection-span ratio increases gradually. The measured results indicate that the load-deflection relationship curves of corroded channel steel beam may be divided into four sections: the exfoliated rust layer stage,the elastic stage,the yielding stage and the descending stage. The load-strain relationship curves include two sections: the elastic stage and the yielding stage. The strain measurement of web proves that the average strains agree well with the assumption of plane section. This paper could provide some scientific bases for the maintenance and reinforcement of the corroded steel structure.

关键词： steel structure corrosion flexural behavior experimental study bearing capacity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An experimental study on the flexural behavior of heavily steel reinforced beams with high-strength concrete

引用

Frontiers of Structural and Civil Engineering 2014年第1期8卷 46-56页

作者： Yasser SHARIFI Ali Akbar MAGHSOUDI Department of Civil Engineering Vali-e-Asr University ofRafsanjan Rafsanjan Iran Department of Civil Engineering Shahid Bahonar University of Kerman Kerman Iran

In recent years, an emerging technology termed high-strength concrete （HSC） has become popular in construction industry. Present study describes an experimental research on the behavior of high-strength concrete beams in ultimate and service state. Six simply supported beams were tested, by applying comprising two symmetric concentrated loads. Tests are reported in this study on the flexural behavior of high-strength reinforced concrete （HSRC） beams made with coarse and fine aggregate together with Microsilica. Test parameter considered includes effect of being compressive reinforcement. Based on the obtained results, the behavior of such members is more deeply reviewed. Also a comparison between theoretical and experimental results is reported here. The beams were made from concrete having compressive strength of 66.81-77.72 N/mm2 and percentage reinforcement ratio （P/Pb） in the range of 0.56% - 1.20%. The ultimate moment for the tested beams was found to be in a good agreement with that of the predicted ultimate moment based on ACI 318-11, ACI 363 and C SA-04 provisions. The predicted deflection based classical formulation based on code provisions for serviceability requirements is found to underestimate the maximum deflection of HSC reinforced beams at service load.

关键词： high-strength concrete （HSC） members flexural behavior reinforced concrete experimental results ultimatemoment

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Experimental Study on flexural behavior of Post-Tensioning Bonded Partially Prestressed Ultra-High Strength Concrete Beams

引用

Journal of Harbin Institute of Technology(New Series) 2015年第2期22卷 94-102页

作者： Jinqing Jia Gang Meng Institute of Structural Engineering Dalian University of Technology

This paper presents the results of four partially prestressed ultra-high strength concrete beams in flexure. The test results are used to evaluate the effects of prestressing tendon depth and area on flexure behavior of specimen beams. The test results indicate that: the cracking load,yielding load,peak load and stiffness postcracking of specimen beams are enhanced by reducing prestressing tendon depth or increasing prestressing tendon area, and the flexural ductility is improved by increasing prestressing tendon depth or reducing prestressing tendon area. The effect of complex reinforcement index considering the strength of the equivalence principle and the reinforcement position on loading levels under serviceability limit state,flexural strength and displacement ductility factor are studied. The influence coefficient of prestressing tendon kpis introduced in the complex reinforcement index. As the complex reinforcement index increases, the loading levels under serviceability limit state and flexural strength increases linearly,and the displacement ductility factor decreases linearly. The test results also verify the conventional beam flexural theory based on the plane cross-section assumption for predicting ultimate flexural strength of partially prestressed ultra-high strength concrete beams is valid. After the introduction of the coefficient kp,the calculation method of cracks in code for design of concrete structure in china are appropriated for the specimen beams.

关键词： partially prestressed ultra-high strength concrete flexural behavior ductility serviceability limit state

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Exploring the mechanical properties of steel-and polypropylene-reinforced ultra-high-performance concrete through numerical analyses and experimental multi-target digital image correlation

引用

Frontiers of Structural and Civil Engineering 2023年第8期17卷 1228-1248页

作者： Behrooz DADMAND Hamed SADAGHIAN Sahand KHALILZADEHTABRIZI Masoud POURBABA Amir MIRMIRAN Department of Civil Engineering University of RaziKermanshah ***Iran Department of Civil Engineering University of TabrizTabriz ***Iran Ingram School of Engineering Texas State UniversitySan MarcosTX 78666USA University of Texas at Tyler TylerTX 75799USA

This study presents experimental and numerical investigations on the mechanical properties of ultrahigh-performance concrete(UHPC)reinforced with single and hybrid micro-and macro-steel and polypropylene fibers.For this purpose,a series of cubic,cylindrical,dog-bone,and prismatic beam specimens(total fiber by volume=1%,and 2%)were tested under compressive,tensile,and flexural loadings.A method,namely multi-target digital image correlation(MT-DIC)was used to monitor the displacement and deflection values.The obtained experimental data were subsequently used to discuss influential parameters,i.e.,flexural strength,tensile strength,size effect,etc.Numerical analyses were also carried out using finite element software to account for the sensitivity of different parameters.Furthermore,nonlinear regression analyses were conducted to obtain the flexural load-deflection curves.The results showed that the MT-DIC method was capable of estimating the tensile and flexural responses as well as the location of the crack with high accuracy.In addition,the regression analyses showed excellent consistency with the experimental results,with correlation coefficients close to unity.Furthermore,size-effect modeling revealed that modified Bazant theory yielded the best estimation of the size-effect phenomenon compared to other models.

关键词： UHPC MT-DIC flexural behavior tensile behavior steel fiber polypropylene fiber

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Performance of Epoxy-Repaired Corroded Reinforced Concrete Beams

引用

Transactions of Nanjing University of Aeronautics and Astronautics 2015年第5期32卷 579-584页

作者：李洪明吴瑾王喆尚保康 College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics

Reinforcement corrosion has a serious impact on the durability and safety of reinforced concrete structures.Six reinforced concrete(RC)beam specimens are constructed.After beam specimens are subjected to accelerated corrosion with the constant current,beam specimens are repaired with epoxy mortar and the flexural test of beams is investigated.Then the behaviors of repaired corroded reinforced concrete beams are evaluated.The experimental results show that cracking and ultimate loads of corroded RC beams are enhanced after being repaired.And the strain distributions measured across sections of beam specimens still obey the assumption of plane section.After being repaired,the number of cracks decreases and the crack spacing increases.

关键词： corrosion reinforced concrete beam epoxy mortar flexural behavior repair

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：