Pub Date : 2021-04-03DOI: 10.1080/13287982.2021.1923158
M. Tahir, Zhenyu Wang, Zhou Wei, Rizwan Jameel
ABSTRACT Fibre-reinforced polymer (FRP) bars have been acknowledged by the researchers as well as practitioners in the construction industry as effective alternatives to conventional steel in a corrosive environment. However, the application of FRP bars as longitudinal reinforcement in columns has not yet gained an adequate level of confidence due to limited research studies and lack of standard design guidelines. In the past, only a few studies have focused on FRP-reinforced concrete (FRP-RC) columns under eccentric loadings. This study focused on development of a finite element model (FEM) for FRP-RC columns subjected to axial compression loadings. FEM was calibrated against the test results of studies available in the literature. A design-oriented analytical model was developed using sectional analysis to calculate the axial load and bending moment capacity of FRP-RC columns. FEM and analytical model predicted load–displacement behaviour and peak load with close agreement to the test results. Finally, a parametric analysis was accomplished to explore the effect of concrete grade, FRP-reinforcement ratio, and slenderness ratio of columns. Based on the parametric study, it is recommended to reduce the limit of slenderness ratio to 14.2 and 21.2 for concrete columns, bent in single curvature, reinforced with GFRP and CFRP bars, respectively.
{"title":"Numerical and Analytical Modeling of FRP-Reinforced Concrete Columns Subjected to Compression Loading","authors":"M. Tahir, Zhenyu Wang, Zhou Wei, Rizwan Jameel","doi":"10.1080/13287982.2021.1923158","DOIUrl":"https://doi.org/10.1080/13287982.2021.1923158","url":null,"abstract":"ABSTRACT Fibre-reinforced polymer (FRP) bars have been acknowledged by the researchers as well as practitioners in the construction industry as effective alternatives to conventional steel in a corrosive environment. However, the application of FRP bars as longitudinal reinforcement in columns has not yet gained an adequate level of confidence due to limited research studies and lack of standard design guidelines. In the past, only a few studies have focused on FRP-reinforced concrete (FRP-RC) columns under eccentric loadings. This study focused on development of a finite element model (FEM) for FRP-RC columns subjected to axial compression loadings. FEM was calibrated against the test results of studies available in the literature. A design-oriented analytical model was developed using sectional analysis to calculate the axial load and bending moment capacity of FRP-RC columns. FEM and analytical model predicted load–displacement behaviour and peak load with close agreement to the test results. Finally, a parametric analysis was accomplished to explore the effect of concrete grade, FRP-reinforcement ratio, and slenderness ratio of columns. Based on the parametric study, it is recommended to reduce the limit of slenderness ratio to 14.2 and 21.2 for concrete columns, bent in single curvature, reinforced with GFRP and CFRP bars, respectively.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91107434","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}
Pub Date : 2021-04-03DOI: 10.1080/13287982.2021.1918376
J. Holmes
ABSTRACT This paper reviews the numbers of tropical cyclones in the southern Indian Ocean, and the land-falling cyclones that have impacted the Pilbara and Gascoyne coastlines of Western Australia since 1970, with particular emphasis on those of Category 4 strength and above. It shows reductions in impacts of severe cyclones on that coastline in the most recent two decades. Nearly as many severe cyclones have impacted the coast outside the current northern boundary of Region D in AS/NZS 1170.2 as have occurred within that boundary, suggesting the limits of Region D may need reviewing. Recorded and corrected extreme wind gusts exceeding 22 m/s from eight coastal stations have been processed as a group, and individually for 3 stations with long records. This indicates that the extreme value distribution in the draft standard DR AS/NZS 1170.2:2020 is quite adequate, without any additional factors, but the predicted extreme wind speeds for Carnarvon are well under the Region D specifications. The calculated wind direction multipliers for Region D show higher values from east and northeast; this can be explained by the wind directions generated by the clockwise rotations created by the cyclonic vortices, as the storms cross the coastline, or as they pass along the coastline at near full strength.
{"title":"Tropical cyclone impacts on the Western Australian coast and extreme wind speeds in Region D","authors":"J. Holmes","doi":"10.1080/13287982.2021.1918376","DOIUrl":"https://doi.org/10.1080/13287982.2021.1918376","url":null,"abstract":"ABSTRACT This paper reviews the numbers of tropical cyclones in the southern Indian Ocean, and the land-falling cyclones that have impacted the Pilbara and Gascoyne coastlines of Western Australia since 1970, with particular emphasis on those of Category 4 strength and above. It shows reductions in impacts of severe cyclones on that coastline in the most recent two decades. Nearly as many severe cyclones have impacted the coast outside the current northern boundary of Region D in AS/NZS 1170.2 as have occurred within that boundary, suggesting the limits of Region D may need reviewing. Recorded and corrected extreme wind gusts exceeding 22 m/s from eight coastal stations have been processed as a group, and individually for 3 stations with long records. This indicates that the extreme value distribution in the draft standard DR AS/NZS 1170.2:2020 is quite adequate, without any additional factors, but the predicted extreme wind speeds for Carnarvon are well under the Region D specifications. The calculated wind direction multipliers for Region D show higher values from east and northeast; this can be explained by the wind directions generated by the clockwise rotations created by the cyclonic vortices, as the storms cross the coastline, or as they pass along the coastline at near full strength.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85820660","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}
Pub Date : 2021-04-03DOI: 10.1080/13287982.2021.1912518
Mohamed A. Farouk, Khaled F. Khalil
ABSTRACT Computing the moments in RC structures after the yield by linear elastic analysis can lead to an inaccurate assessment of the behaviour due to the nonlinear behaviour. Therefore, it can become necessary to use more advanced methodologies to achieve a higher degree of performance optimisation of structures than those resulting from the simplified approaches adopted by existing design codes based on linear elastic analysis with redistribution of internal forces. The moment redistribution is supposed to start after occurring the cracks of concrete, but with small ratio. In this study, the moment redistribution before the yielding will be neglected, and the redistribution is focused after the yield. This paper suggests a mathematical model to investigate the moment redistribution in RC beams after yielding analytically. In the suggested mathematical model, the beam after forming the plastic hinges is converted into a virtual beam that can be analysed by structural linear analysis. The plastic hinges in the virtual beam will be represented as rotational springs having a linear rotational stiffness against the induced moment. The actual moments can be found through derived relationships in the mathematical model between it and the virtual moment. The mathematical model was verified and it gave values of moment matching experimental results. Also, a comparison for degree of moment redistribution among the suggested mathematical model and several design codes was performed. The analytical results indicate that the proposed mathematical model can be used for analysis of moment redistribution of RC beams.
{"title":"New analytical method for computing moment redistribution in RC beams under concentrated load","authors":"Mohamed A. Farouk, Khaled F. Khalil","doi":"10.1080/13287982.2021.1912518","DOIUrl":"https://doi.org/10.1080/13287982.2021.1912518","url":null,"abstract":"ABSTRACT Computing the moments in RC structures after the yield by linear elastic analysis can lead to an inaccurate assessment of the behaviour due to the nonlinear behaviour. Therefore, it can become necessary to use more advanced methodologies to achieve a higher degree of performance optimisation of structures than those resulting from the simplified approaches adopted by existing design codes based on linear elastic analysis with redistribution of internal forces. The moment redistribution is supposed to start after occurring the cracks of concrete, but with small ratio. In this study, the moment redistribution before the yielding will be neglected, and the redistribution is focused after the yield. This paper suggests a mathematical model to investigate the moment redistribution in RC beams after yielding analytically. In the suggested mathematical model, the beam after forming the plastic hinges is converted into a virtual beam that can be analysed by structural linear analysis. The plastic hinges in the virtual beam will be represented as rotational springs having a linear rotational stiffness against the induced moment. The actual moments can be found through derived relationships in the mathematical model between it and the virtual moment. The mathematical model was verified and it gave values of moment matching experimental results. Also, a comparison for degree of moment redistribution among the suggested mathematical model and several design codes was performed. The analytical results indicate that the proposed mathematical model can be used for analysis of moment redistribution of RC beams.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80257299","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}
Pub Date : 2021-01-02DOI: 10.1080/13287982.2021.1876439
M. A. Alam, A. Sami
ABSTRACT Optimisation of CFRP shear strip in presence of connectors/anchors is the current interest to reduce retrofitting cost of structures. The main aim of this research was to propose design guideline considering strain compatibility nature between shear reinforcement and externally bonded CFRP laminate to optimise the dimension of CFRP laminate for shear strengthening of RC beam in presence of embedded connectors. The guideline had been experimentally verified through the structural investigations on five reinforced concrete beams. Results showed that the proposed guideline with connectors reduced the dimension of CFRP laminate significantly. The optimal strengthened beams had shown the highest flexural capacities, maximum ductility and cost effective structural performances. Shear reinforcement and externally bonded CFRP laminate had shown identical nature of strains until shear crack and micro debonding of laminate. The optimal strengthened beams with connector did not fail by shear or debonding of laminates prior to theoretical design shear capacities of beams. The design shear capacities of optimal strengthened beams (182 kN) were very close to those of flexural failure loads (181 kN and 184 kN). Overall experimental results satisfactorily verified the proposed design guideline.
{"title":"Strain compatibility model to optimise CFRP laminate for shear strengthening of RC beam","authors":"M. A. Alam, A. Sami","doi":"10.1080/13287982.2021.1876439","DOIUrl":"https://doi.org/10.1080/13287982.2021.1876439","url":null,"abstract":"ABSTRACT Optimisation of CFRP shear strip in presence of connectors/anchors is the current interest to reduce retrofitting cost of structures. The main aim of this research was to propose design guideline considering strain compatibility nature between shear reinforcement and externally bonded CFRP laminate to optimise the dimension of CFRP laminate for shear strengthening of RC beam in presence of embedded connectors. The guideline had been experimentally verified through the structural investigations on five reinforced concrete beams. Results showed that the proposed guideline with connectors reduced the dimension of CFRP laminate significantly. The optimal strengthened beams had shown the highest flexural capacities, maximum ductility and cost effective structural performances. Shear reinforcement and externally bonded CFRP laminate had shown identical nature of strains until shear crack and micro debonding of laminate. The optimal strengthened beams with connector did not fail by shear or debonding of laminates prior to theoretical design shear capacities of beams. The design shear capacities of optimal strengthened beams (182 kN) were very close to those of flexural failure loads (181 kN and 184 kN). Overall experimental results satisfactorily verified the proposed design guideline.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76687191","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}
Pub Date : 2021-01-02DOI: 10.1080/13287982.2021.1872978
A. Chourasia, Shubham Singhal, P. Bhargava
ABSTRACT Different codes provide a range of values for structural behaviour factor for various masonry building systems. High variation in structural behaviour factors in different codes arises mainly due to the lack of information from experimental studies. Thus, the present paper highlights investigation of behaviour of different masonry construction systems through full-scale tests on masonry buildings subjected to cyclic displacement. Six tests, out of which three on virgin masonry building systems, employing unreinforced masonry (URM), reinforced masonry (RM) and confined masonry (CM) having similar geometrical, material, constructional features and test procedures were conducted. The remaining three building models tested included repaired unreinforced masonry (URM-REP), retrofitted unreinforced masonry (URM-RET) and retrofitted reinforced masonry (RM-RET). Observations and data from the experiments have been co-related between damage index, grade of damage and displacement capacity, thereby estimation of structural behaviour factor for different masonry building typologies. The analysis shows that the ranges of structural behaviour factor mentioned in codes are adequate for URM and RM, while the same for CM is conservative, which can be relaxed. Also, it has been noticed that there is a substantial increase in structural behaviour factor for repaired and retrofitted masonry structures, thus proving the structural adequacy of retrofitting measures.
{"title":"Damage limitation and structural behaviour factor for masonry structures","authors":"A. Chourasia, Shubham Singhal, P. Bhargava","doi":"10.1080/13287982.2021.1872978","DOIUrl":"https://doi.org/10.1080/13287982.2021.1872978","url":null,"abstract":"ABSTRACT Different codes provide a range of values for structural behaviour factor for various masonry building systems. High variation in structural behaviour factors in different codes arises mainly due to the lack of information from experimental studies. Thus, the present paper highlights investigation of behaviour of different masonry construction systems through full-scale tests on masonry buildings subjected to cyclic displacement. Six tests, out of which three on virgin masonry building systems, employing unreinforced masonry (URM), reinforced masonry (RM) and confined masonry (CM) having similar geometrical, material, constructional features and test procedures were conducted. The remaining three building models tested included repaired unreinforced masonry (URM-REP), retrofitted unreinforced masonry (URM-RET) and retrofitted reinforced masonry (RM-RET). Observations and data from the experiments have been co-related between damage index, grade of damage and displacement capacity, thereby estimation of structural behaviour factor for different masonry building typologies. The analysis shows that the ranges of structural behaviour factor mentioned in codes are adequate for URM and RM, while the same for CM is conservative, which can be relaxed. Also, it has been noticed that there is a substantial increase in structural behaviour factor for repaired and retrofitted masonry structures, thus proving the structural adequacy of retrofitting measures.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79872117","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}
Pub Date : 2021-01-02DOI: 10.1080/13287982.2021.1872994
Saranya Ilango, Vivek Singh, Chayanika Gogoi
ABSTRACT The utilization of industrial waste as a partial replacement in construction materials has been increasing rapidly in recent years. This Paper investigates the performance of reinforced concrete columns comprising of recycled aggregates, fly ash and synthetic fibres in varying percentage, under monotonic and thermal loads. Ten full scale reinforced concrete columns of size 150 x 150 x 750 mm were experimentally studied under compressive loads. Results of the experiment showed that the polypropylene (PP) fibre reinforced fly ash column with recycled aggregate consisting of 1.5% PP fibre, 15% fly ash and 25% recycled aggregates exhibited better load carrying and deflection capacities and was further considered for numerical analysis. The conventional column was modelled as a control specimen and the behaviour of polypropylene fibre-reinforced fly ash column with recycled aggregate was comparatively studied under the action of thermal loads in ABAQUS. In order to understand the effect of fibre-reinforced polymer (FRP) rebar reinforcement in columns under thermal loads, a parametric study was carried out by varying the type of reinforcement, using carbon fibre-reinforced polymer rebar (CFRP) and glass fibre-reinforced polymer rebar (GFRP). The polypropylene fibre-reinforced fly ash column with recycled aggregate reinforced with CFRP rebars exhibited better performance under thermal loads.
{"title":"Effect of fly ash cement and polypropylene fibre on the performance of recycled aggregate concrete column under thermal loading: Experimental and numerical study","authors":"Saranya Ilango, Vivek Singh, Chayanika Gogoi","doi":"10.1080/13287982.2021.1872994","DOIUrl":"https://doi.org/10.1080/13287982.2021.1872994","url":null,"abstract":"ABSTRACT The utilization of industrial waste as a partial replacement in construction materials has been increasing rapidly in recent years. This Paper investigates the performance of reinforced concrete columns comprising of recycled aggregates, fly ash and synthetic fibres in varying percentage, under monotonic and thermal loads. Ten full scale reinforced concrete columns of size 150 x 150 x 750 mm were experimentally studied under compressive loads. Results of the experiment showed that the polypropylene (PP) fibre reinforced fly ash column with recycled aggregate consisting of 1.5% PP fibre, 15% fly ash and 25% recycled aggregates exhibited better load carrying and deflection capacities and was further considered for numerical analysis. The conventional column was modelled as a control specimen and the behaviour of polypropylene fibre-reinforced fly ash column with recycled aggregate was comparatively studied under the action of thermal loads in ABAQUS. In order to understand the effect of fibre-reinforced polymer (FRP) rebar reinforcement in columns under thermal loads, a parametric study was carried out by varying the type of reinforcement, using carbon fibre-reinforced polymer rebar (CFRP) and glass fibre-reinforced polymer rebar (GFRP). The polypropylene fibre-reinforced fly ash column with recycled aggregate reinforced with CFRP rebars exhibited better performance under thermal loads.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77400153","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}
Pub Date : 2021-01-02DOI: 10.1080/13287982.2021.1889089
Anup Kc, F. Javidan
ABSTRACT Recent developments in technology and manufacturing of steel has led to a significant increase in the strength of this material while keeping the weight constant. This has resulted in an increase in the application of high strength steel material in structural practice and consequently a rising demand in updated design guidelines. The present research covers compression experiments and design of ultra-high strength steel hollow circular members with a nominal yield strength of 1250 MPa. The performance is compared against two other grades of steel: Mild Steel grade 300 and high strength steel grade 750. Different section geometries are modelled using finite element software and validated against the experimental compression tests. A parametric analysis is conducted on a range of section geometries and lengths and the result are compared against current design guidelines of AS4100, and AISC360. The compressive performance is studied considering both the section slenderness and the member slenderness ratios. The results show that as the member slenderness and yield strength of the sections increase, the standard predictions give a more conservative prediction of the compression capacity. Using proposed modifications for member slenderness limits and compression capacity factors, design recommendations are suggested for grade 1200 steel
{"title":"Circular hollow compression members of grade 1200 steel: experiments and design","authors":"Anup Kc, F. Javidan","doi":"10.1080/13287982.2021.1889089","DOIUrl":"https://doi.org/10.1080/13287982.2021.1889089","url":null,"abstract":"ABSTRACT Recent developments in technology and manufacturing of steel has led to a significant increase in the strength of this material while keeping the weight constant. This has resulted in an increase in the application of high strength steel material in structural practice and consequently a rising demand in updated design guidelines. The present research covers compression experiments and design of ultra-high strength steel hollow circular members with a nominal yield strength of 1250 MPa. The performance is compared against two other grades of steel: Mild Steel grade 300 and high strength steel grade 750. Different section geometries are modelled using finite element software and validated against the experimental compression tests. A parametric analysis is conducted on a range of section geometries and lengths and the result are compared against current design guidelines of AS4100, and AISC360. The compressive performance is studied considering both the section slenderness and the member slenderness ratios. The results show that as the member slenderness and yield strength of the sections increase, the standard predictions give a more conservative prediction of the compression capacity. Using proposed modifications for member slenderness limits and compression capacity factors, design recommendations are suggested for grade 1200 steel","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80201305","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}
Pub Date : 2021-01-02DOI: 10.1080/13287982.2021.1872992
A. Al-Mosawe, R. Al-Mahaidi, Dia Alwash, X. Zhao
ABSTRACT Pre-stressed unbonded retrofit (PUR) CFRP strengthening of steel structures is becoming a common method of strengthening metallic structures. This paper presents a comprehensive study on the use of the PUR CFRP-strengthening method for strengthening a steel bridge in Melbourne, Australia. Finite element analysis is performed in this study to model the entire bridge and the strengthened element, and the model is validated using actual on-site measurements which showed the stress developments of two girders before and after strengthening when a fully loaded truck passed over the bridge. A parametric study is performed to investigate the stress development of steel girders strengthened with the PUR system under different girder-deck levels of rigidity. The results showed a perfect match between the finite element modelling and actual measurements, and the effectiveness of the PUR system under critical conditions such as different girder-deck stiffness connection levels.
{"title":"Finite element simulation of unbonded retrofitting system for a steel bridge in Australia","authors":"A. Al-Mosawe, R. Al-Mahaidi, Dia Alwash, X. Zhao","doi":"10.1080/13287982.2021.1872992","DOIUrl":"https://doi.org/10.1080/13287982.2021.1872992","url":null,"abstract":"ABSTRACT Pre-stressed unbonded retrofit (PUR) CFRP strengthening of steel structures is becoming a common method of strengthening metallic structures. This paper presents a comprehensive study on the use of the PUR CFRP-strengthening method for strengthening a steel bridge in Melbourne, Australia. Finite element analysis is performed in this study to model the entire bridge and the strengthened element, and the model is validated using actual on-site measurements which showed the stress developments of two girders before and after strengthening when a fully loaded truck passed over the bridge. A parametric study is performed to investigate the stress development of steel girders strengthened with the PUR system under different girder-deck levels of rigidity. The results showed a perfect match between the finite element modelling and actual measurements, and the effectiveness of the PUR system under critical conditions such as different girder-deck stiffness connection levels.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88434846","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}
Pub Date : 2021-01-02DOI: 10.1080/13287982.2020.1862973
P. Lu, Chenhao Zhou, Simin Huang, Dengguo Li
ABSTRACT The seamless expansion joint has received considerable attention as a new type of bridge expansion joint owing to its good integrity and driving comfort. To satisfy the requirements of both deformation and road use, the high-temperature stability and low-temperature crack resistance of the asphalt binder for the seamless expansion joint are particularly important. In this study, a temperature scanning test, high-temperature creep test, and low-temperature stress relaxation test of Matrix 502 and Colas, as the asphalt binders in the seamless expansion joints of bridges, were performed before and after ageing using a dynamic shear rheometer. An analysis of the test results revealed that both asphalts had an outstanding stress-relaxation ability and resistance to high-temperature deformation. The maximum stress relaxation of modified asphalt coals with good performance was 83%, and the permanent deformation after short-term ageing was only 0.48%. Additionally, the technical indicators according to the Swiss Federal Road Office for seamless expansion joint road guidelines and the United States Strategic Highway Research Program applicable to the asphalt binder used in the seamless expansion joint of bridges were examined with focus on the development of cost-effective bituminous mixtures for seamless expansion joints.
{"title":"Study on rheological properties of asphalt binders for seamless expansion joints of bridges","authors":"P. Lu, Chenhao Zhou, Simin Huang, Dengguo Li","doi":"10.1080/13287982.2020.1862973","DOIUrl":"https://doi.org/10.1080/13287982.2020.1862973","url":null,"abstract":"ABSTRACT The seamless expansion joint has received considerable attention as a new type of bridge expansion joint owing to its good integrity and driving comfort. To satisfy the requirements of both deformation and road use, the high-temperature stability and low-temperature crack resistance of the asphalt binder for the seamless expansion joint are particularly important. In this study, a temperature scanning test, high-temperature creep test, and low-temperature stress relaxation test of Matrix 502 and Colas, as the asphalt binders in the seamless expansion joints of bridges, were performed before and after ageing using a dynamic shear rheometer. An analysis of the test results revealed that both asphalts had an outstanding stress-relaxation ability and resistance to high-temperature deformation. The maximum stress relaxation of modified asphalt coals with good performance was 83%, and the permanent deformation after short-term ageing was only 0.48%. Additionally, the technical indicators according to the Swiss Federal Road Office for seamless expansion joint road guidelines and the United States Strategic Highway Research Program applicable to the asphalt binder used in the seamless expansion joint of bridges were examined with focus on the development of cost-effective bituminous mixtures for seamless expansion joints.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78933303","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}
Pub Date : 2020-12-26DOI: 10.1080/13287982.2020.1862968
Amauri da Silva Ribas Junior, J. C. Molina
ABSTRACT The county of Itapeva – SP, Brazil, has a great territorial extension, with many vicinal roads and, consequently, many wooden bridges with some type of problem. This research had the purpose of analysing 34 wooden bridges, with decks formed by natural longitudinal beams connected to the sawn transverse boards, to identify the main problems presented and proposition of solutions. The great majority of the analysed bridges (82.35%) presented a small span (up to 15 m), and the analysed spans ranged from 5 m to 44 m approximately. The lack of of preservative treatment was a problem for all analyzed bridges and this is a great factor that contributes to the reduction of the lifetime of the bridges. As a result of this work, the main construction and calculation recommendations for wooden bridges are presented. Two pre-sizing tables are also presented to guide builders and other interested parties in the construction of wooden bridges, in order to obtain secure structures, low cost and with guaranteed durability.
{"title":"Wooden bridges with deck of sawn board and round beams: main orientations","authors":"Amauri da Silva Ribas Junior, J. C. Molina","doi":"10.1080/13287982.2020.1862968","DOIUrl":"https://doi.org/10.1080/13287982.2020.1862968","url":null,"abstract":"ABSTRACT The county of Itapeva – SP, Brazil, has a great territorial extension, with many vicinal roads and, consequently, many wooden bridges with some type of problem. This research had the purpose of analysing 34 wooden bridges, with decks formed by natural longitudinal beams connected to the sawn transverse boards, to identify the main problems presented and proposition of solutions. The great majority of the analysed bridges (82.35%) presented a small span (up to 15 m), and the analysed spans ranged from 5 m to 44 m approximately. The lack of of preservative treatment was a problem for all analyzed bridges and this is a great factor that contributes to the reduction of the lifetime of the bridges. As a result of this work, the main construction and calculation recommendations for wooden bridges are presented. Two pre-sizing tables are also presented to guide builders and other interested parties in the construction of wooden bridges, in order to obtain secure structures, low cost and with guaranteed durability.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88542668","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}
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