IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure最新文献

{"title":"Strengthening of reinforced concrete beams: RC versus UHPFRC layers","authors":"A. Lampropoulos, O. Tsioulou, Spyridon A. Paschalis, S. Dritsos","doi":"10.2749/CHRISTCHURCH.2021.0589","DOIUrl":"https://doi.org/10.2749/CHRISTCHURCH.2021.0589","url":null,"abstract":"Strengthening of Reinforced Concrete (RC) beams is of high importance for the structural upgrade of existing buildings. The majority of the existing RC structures need to be upgraded either because they are designed with old or without seismic code provisions or because of existing damages. In this study the effectiveness of the use of traditional RC layers is compared with the use of Ultra High Performance Fibre Reinforced Concrete (UHPFRC) layers. Experimental investigation has been conducted on beams strengthened with these two techniques and the effectiveness of the examined methods has been evaluated via comparisons of the load-deflection and the interface slip results.","PeriodicalId":186947,"journal":{"name":"IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127742977","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}

{"title":"Assessment of corrosion-induced bond deterioration in reinforced concrete: towards a splitting crack-based approach","authors":"Michele Win Tai Mak, J. Lees","doi":"10.2749/CHRISTCHURCH.2021.0062","DOIUrl":"https://doi.org/10.2749/CHRISTCHURCH.2021.0062","url":null,"abstract":"Reinforced concrete structures are subjected to several sources of deterioration that can reduce their load-resisting capacity over time. This has significant consequences for the management of infrastructure, leading to high costs of maintenance, repair, strengthening and premature decommissioning. Assessing the residual capacity of structures is challenging but paramount to manage the infrastructure network effectively. Corrosion of the internal steel reinforcement is among the main causes of deterioration in reinforced concrete bridges. The subsequent reduction in steel-to-concrete bond strength is difficult to evaluate with accuracy. There is no unified theory of general validity. Most existing models adopt measures of the level of corrosion as the key parameter to evaluate the bond reduction. In this paper, a different approach is investigated. Corrosion-induced splitting crack widths are used as the fundamental indicator of bond strength reduction, irrespective of the associated degree of steel corrosion. Available experimental results on deformed steel bars embedded in concrete subjected to either natural or accelerated corrosion, with or without transverse reinforcement, are analysed and compared with a different perspective. The analysis indicates that this new splitting crack-based approach can lead to more accurate predictions. This contributes to a better understanding of the fundamental principles underlying bond of corroded reinforcing bars. Enhanced assessment strategies can lead to a reduction of the safety risks, maintenance costs and environmental footprint of the infrastructure network.","PeriodicalId":186947,"journal":{"name":"IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131691166","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}

{"title":"Development of an innovative one part green concrete","authors":"O. Tsioulou, A. Lampropoulos, K. Neocleous, N. Kyriakides, T. Polydorou","doi":"10.2749/CHRISTCHURCH.2021.0874","DOIUrl":"https://doi.org/10.2749/CHRISTCHURCH.2021.0874","url":null,"abstract":"Concrete is one of the most commonly used construction materials. However, the main drawbacks in the use of concrete are related to the use of cement and subsequently the high percentage of carbon dioxide emissions. The use of cement substitutes is an area where there is a lot of ongoing research. Geopolymer concrete is a concrete in which cement is replaced by waste materials such as Pulverised Fuel Ash (PFA), or Ground Granulated Blast furnace Slag (GGBS). To activate the geopolymerisation, an alkali activator is used. The procedure, which is used for the production of a geopolymer concrete, is normally a two-part procedure: Preparation of the alkali activator one day before the mixing and mixing of the aluminosilicate sources (PFA, GGBS) with the activator. To make the production of geopolymers more user friendly it needs to be converted to one part procedure where water will be added in a readymade mix. In the published literature, there is research on one- part geopolymers, but there are limited studies on the use of demolition waste materials as substitution of PFA and GGBS in this type of materials. With the current study, different sources of raw materials focusing on demolition waste materials such as red bricks and reclaimed concrete, which are commonly used in construction worldwide, will be examined for the production of one- part geopolymer. The major aim of this research proposal is to develop an innovative sustainable one-part cement free geopolymer concrete. The new concrete is a “green” concrete where cement is replaced by waste materials. Construction demolition materials such as red bricks can be used as raw materials in the geopolymer matrix. This project will focus on the selection, characterisation and development of the appropriate processing of these red bricks so as they can be used as raw materials in the geopolymer matrix. Also, the development of one part mix where the new concrete will be ready for use by adding only water in it, is another aim of the proposed project.","PeriodicalId":186947,"journal":{"name":"IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129412207","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}

{"title":"Finite element (FE) analysis of H-Beam – composite POSCO (P)-Box column joints with new inner diaphragms","authors":"Mahbub H. Khan, B. Uy","doi":"10.2749/CHRISTCHURCH.2021.1289","DOIUrl":"https://doi.org/10.2749/CHRISTCHURCH.2021.1289","url":null,"abstract":"This paper presents a numerical investigation of a H-beam – composite P-box column joint fabricated with two new inner diaphragms and a continuous inner diaphragm. The main objective of the current research is to investigate the structural performance of the newly developed inner diaphragms of POSCO under a cyclic loading. Hysteretic behaviour of the composite joints is analysed to investigate the structural performance of the new and continuous inner diaphragms. Furthermore, yield line behaviour of the new inner diaphragms is investigated to predict the failure mode under tensile load. To produce a design criterion for the newly developed inner diaphragms and continuous inner diaphragm, yielding or predicted failure area of the inner diaphragms under tensile stress is utilised from the FE results.","PeriodicalId":186947,"journal":{"name":"IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131148022","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}

{"title":"Modal shape identification for short and medium span bridges using wavelet based vehicular sensing approach","authors":"Xudong Jian, Limin Sun, Ye Xia","doi":"10.2749/CHRISTCHURCH.2021.0567","DOIUrl":"https://doi.org/10.2749/CHRISTCHURCH.2021.0567","url":null,"abstract":"Modal parameter identification has been one of the key issues in the research of indirect bridge structural health monitoring. This paper presents a new indirect approach identifying modal parameters for short and medium span bridges, using dynamic responses of three connected vehicles. Accelerations of these vehicles are firstly subtracted to eliminate road roughness effects, so that the bridge frequency visibility in the frequency domain is improved. The wavelet analysis is performed to identify modal frequencies and shapes of bridges from the subtracted acceleration of moving vehicles. Systematic numerical experiments are performed to investigate the fidelity of the approach. Results show that the proposed approach can identify the bridge modal frequencies and shapes with promising accuracy and robustness.","PeriodicalId":186947,"journal":{"name":"IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125014355","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}

{"title":"Risk analysis in the design of timber portal frames with semi-rigid knee joints","authors":"L. Ozola, Janis Fabriciuss","doi":"10.2749/CHRISTCHURCH.2021.1104","DOIUrl":"https://doi.org/10.2749/CHRISTCHURCH.2021.1104","url":null,"abstract":"The complex behaviour of anisotropic wood material and semi-rigid connections in knee joints of timber portal frames leads to a discussion on additional design conditions entailing strength failure criteria. Also the assessment of the consequences of deformation development and increase of global displacements of a system due to the load duration impact in semi-rigid connections is essentially important for a sustainable design. Some important affecting factors: the resistance of wood in tension perpendicular to the direction of the grain, development of deformations in semi- rigid connections and uncertainty of bearing capacity are examined regarding their role in a safety format.","PeriodicalId":186947,"journal":{"name":"IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129561755","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}

{"title":"Eddy current based evaluation of axial force of high-strength bolts","authors":"Ayako Akutsu, Sanjeema Bajracharya, E. Sasaki, T. Shimozato, M. Tai","doi":"10.2749/CHRISTCHURCH.2021.0045","DOIUrl":"https://doi.org/10.2749/CHRISTCHURCH.2021.0045","url":null,"abstract":"Many bridges have been in service for over 40 years and face to the repapering or reinforcing period due to deterioration. Particularly, in a high-strength bolts used for joints may be loosened due to co-rotation, corrosion, or vibration caused by the vehicles. Thus, it is important to evaluate an axial force of the high-strength bolts. In this research, an axial force evaluation of high-strength bolt using eddy current that does not require measurement preparation has been investigated. The eddy current method is capable of capturing the change in permeability of steel members due to the stress change. Further, the stress distribution of the bolt head is assumed uniform without directionality. Therefore, a numerical simulation and an experiment that measures the output signal of the eddy current probe while introducing axial force to the high-strength bolt has conducted.","PeriodicalId":186947,"journal":{"name":"IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127218677","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}

{"title":"Reverse engineering of existing reinforced concrete slab bridges","authors":"T. Harrewijn, R.P.H. Vergoossen, Royal HaskoningDHV, Eva O. L. Lantsoght","doi":"10.2749/CHRISTCHURCH.2021.0140","DOIUrl":"https://doi.org/10.2749/CHRISTCHURCH.2021.0140","url":null,"abstract":"Most bridges in the Dutch infrastructure are built before 1985 and have experienced increasing traffic intensities and loads. On the other hand, the structural (design) codes have changed over the years. A frequently faced problem in practice is that the original design calculations and technical drawings of a large percentage of the existing bridge stock are unknown or lost. Therefore, the current capacity of the bridge is unknown. The currently used method to map the reinforcement dimensions and amounts in an existing bridge is by (X-ray) scanning. As an alternative, this work proposes Reverse Engineering of the existing bridges, by redoing (a correct) former bridge design with a known design year and load class as a starting point. Consequently, the Reverse Engineered bridge design can be assessed according to the current Eurocodes. A parametric study reveals different capacity margins in bridge design than expected beforehand.","PeriodicalId":186947,"journal":{"name":"IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128518796","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}

{"title":"Push-out tests of shear connectors for new fully assembled steel- concrete composite beams","authors":"H. Hou, Ning Wang, Z. Zang","doi":"10.2749/CHRISTCHURCH.2021.1024","DOIUrl":"https://doi.org/10.2749/CHRISTCHURCH.2021.1024","url":null,"abstract":"To accomplish rapid installation and replaceability, a new type of connector for new fully assembled steel-concrete composite beams was studied. The connectors are fixed on the C-shaped channels of the prefabricated floor slab. The load transfer along the interface of the precast floor slab and the steel beam is primarily achieved through the friction between the beam flange and the channels. Push-out tests were conducted to study the mechanical properties of new composite beam. The effects of different C-shaped channel types, repeated loading and number of connectors were investigated. Test results showed that all the connectors exhibited satisfactory performance. When the section height of C-shaped channel is small, the restraining effect on the connector is more remarkable. The shear strength and shear stiffness of the connectors can be improved by reloading. The formulas for calculating the shear strength derived agree well with the experimental results.","PeriodicalId":186947,"journal":{"name":"IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116815094","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}