Increasing Load-bearing Capacity of Bridge Structures by Reducing Cover Thickness as a Result of Changing Cement Type

Bridges constitute important elements of the transportation network. A vast part of the Italian existing infrastructural system dates to around 60 years ago, which implies that the related bridge structures were constructed according to past design guidelines and underwent a probable state of material deterioration (e.g., steel corrosion, concrete degradation), especially in those cases in which proper maintenance plans have not been periodically performed over the structural lifetime. Consequently, elaborating rapid yet effective safety assessment strategies for existing bridge structures represents a topical research line. This contribution presents a systematic experimental–numerical approach for assessing the load-bearing capacity of existing prestressed concrete (PC) bridge decks. This methodology is applied to the Longano PC viaduct (southern Italy) as a case study. Initially, natural frequencies and mode shapes of the bridge deck are experimentally identified from vibration data collected in situ through Operational Modal Analysis (OMA), based on which a numerical finite element (FE) model is developed and calibrated. In situ static load tests are then carried out to investigate the static deflections under maximum allowed serviceability loads, which are compared to values provided by the FE model for further validation. Since prestressing strands appear corroded in some portions of the main girders, numerical static nonlinear analysis with a concentrated plasticity approach is finally conducted to quantify the effects of various corrosion scenarios on the resulting load-bearing capacity of the bridge at ultimate limit states. The proposed methodology, encompassing both serviceability and ultimate conditions, can be used to identify critical parts of a large infrastructure network prior to performing widespread and expensive material test campaigns, to gain preliminary insight on the structural health of existing bridges and to plan a priority list of possible repairing actions in a reasonable, safe, and costly effective manner.

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Instruments of Probabilistic Optimisation of Load Bearing Capacity and Reliability of Statically Indeterminate Complex Structures

Archives of Civil Engineering ◽

10.2478/ace-2014-0004 ◽

2014 ◽

Vol 60 (1) ◽

pp. 77-90 ◽

Cited By ~ 2

Author(s):

Z. Kowal

Keyword(s):

Bearing Capacity ◽

Failure Mechanisms ◽

Single Element ◽

Complex Structures ◽

Load Bearing Capacity ◽

Load Bearing ◽

Elastic Plastic ◽

Critical Sets ◽

Increasing Load

Abstract The paper presents the method of probabilistic optimisation of load bearing capacity and reliability of statically indeterminate bar structures, and of coupling of members in kinematically admissible failure mechanisms (KAFM), which contain minimal critical sets of elements (MCSE). The latter are characterised by the fact that if only a single element is operational, the whole set is operational too. A method of increasing load bearing capacity and reliability of KAFM built from bars dimensioned in accordance with the code is presented. The paper also shows estimation of load bearing capacity and reliability of KAFM of the optimised structures containing elastic-plastic bars with quasi-brittle connections with nodes. The necessity of increasing connection of load bearing capacity and reliability in relation to bar reliability in order to prevent bars from being excluded from MCSE due to connection fracture is estimated.

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Justification of the development and application of express assessment programs for road bridges when heavy vehicles pass through them

Structural Mechanics of Engineering Constructions and Buildings ◽

10.22363/1815-5235-2021-17-4-315-323 ◽

2021 ◽

Vol 17 (4) ◽

pp. 315-323

Author(s):

Evgeny A. Lugovtsev

Keyword(s):

Reinforced Concrete ◽

Bearing Capacity ◽

Rapid Assessment ◽

Technical Condition ◽

Heavy Vehicles ◽

Load Bearing Capacity ◽

Load Bearing ◽

Bridge Structures ◽

Pass Through ◽

State Registration

The theoretical prerequisites for justifying the development of two rapid assessment programs for road bridges to quickly determine the possibility of passing heavy vehicles on road bridge structures of a split and non-split system, made of wood, metal, steel-reinforced concrete, reinforced concrete with stressed and non-stressed reinforcement, according to the measured angle of rotation of their support sections, taking into account their actual operational condition, are presented. The programs implemented an experimental and analytical method for assessing the technical condition of road bridges for reliability. The features, conditions of application, positive and negative aspects of each version of the program are revealed. The creation of two variants of programs is due to, on the one hand, the need to ensure the safety of the driver of the vehicle and the bridge structure, and on the other hand, the need to guarantee the possibility of safe passage of heavy vehicles, both under the conditions of the load-bearing capacity of superstructures and the load-bearing capacity of road bridge supports, taking into account their actual operational condition. Both developed calculation programs were implemented by using a personal computer and certificates of state registration of computer programs were obtained. The developed programs will be used as part of the modernized IR-AM measuring complex.

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Research of Gfrp Shell Confined Concrete Columns Behavior Under Axial Compression

НАУЧНЫЙ ЖУРНАЛ СТРОИТЕЛЬСТВА И АРХИТЕКТУРЫ ◽

10.36622/vstu.2021.63.3.009 ◽

2021 ◽

pp. 92-102

Author(s):

В. А. Шендрик

Keyword(s):

Bearing Capacity ◽

Concrete Columns ◽

Outer Shell ◽

Experimental Investigations ◽

Plastic Shell ◽

Load Bearing Capacity ◽

Concrete Core ◽

Load Bearing ◽

Glass Fiber Reinforced Plastic ◽

Bridge Structures

Постановка задачи. Исследуется влияние внешних композитных (стеклопластиковых) оболочек, которые имеют различные физико-механические свойства в продольном и поперечном направлениях, на увеличение прочности находящегося внутри оболочек бетонного ядра. Результаты. Представлены результаты экспериментальных исследований несущей способности, позволяющие оценить эффективность применения внешней цельной стеклопластиковой оболочки в качестве усиления бетонной стойки. Результаты исследования позволили определить основной фактор, значительно влияющий на несущую способность гибридной стойки с композитной оболочкой. Выводы. Получен более высокий показатель несущей способности гибридных стоек в сравнении с традиционно применяемыми в мостостроении стойками. Тем самым доказана возможность применения в опорах мостовых сооружений гибридных по материалу стоек, состоящих из внешней цельной стеклопластиковой оболочки и внутреннего бетонного ядра, которые ранее не применялись в мостовых конструкциях. Statement of the problem. The influence of external GFRP (glass-fiber-reinforced-plastic) shell, with different physicomechanical longitudinal and transverse properties on increasing the strength of the concrete core is investigated. Results. The article presents the results of experimental investigations of the load-bearing capacity to evaluate the effectiveness of using a solid fiberglass outer shell as a reinforcement of a concrete column. The results of the study has allowed us to establish the major factor that significantly affects the load-bearing capacity of a hybrid column with a composite shell. Conclusions. A higher load-bearing capacity of hybrid supports in comparison with the concrete columns traditionally used in bridge construction. This proves the possibility of using hybrid columns in the supports of bridge structures consisting of concrete core confined solid fiberglass outer shell that were not previously used in bridge structures.

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Assessment of the Load-Bearing Capacity of Reinforced Concrete Rack With a Composite Cover of a Constructive Element of Bridge Supports

НАУЧНЫЙ ЖУРНАЛ СТРОИТЕЛЬСТВА И АРХИТЕКТУРЫ ◽

10.36622/vstu.2021.62.2.007 ◽

2021 ◽

pp. 86-96

Author(s):

В. А. Шендрик

Keyword(s):

Reinforced Concrete ◽

Bearing Capacity ◽

Composite Shell ◽

Structural Elements ◽

Joint Work ◽

Load Bearing Capacity ◽

Concrete Core ◽

Load Bearing ◽

Fiberglass Shell ◽

Bridge Structures

Постановка задачи. Рассматривается задача разработки методики расчета несущей способности гибридных железобетонных стоек, предназначенных для стоечных опор мостовых сооружений с внешними композитными (стеклопластиковыми) оболочками. Результаты. Сформулированы теоретические зависимости для определения напряжений и относительных деформаций конструктивных элементов гибридной стойки в продольном и поперечном направлениях. Разработанные формулы учитывают совместную работу всесторонне сжатого бетонного ядра с анизотропной стеклопластиковой оболочкой, но не учитывают силовое и средовое воздействие непосредственно на композитную оболочку. Выводы. Полученные теоретические зависимости работы элементов гибридной стойки позволяют разработать методику расчета несущей способности гибридных стоек для опор мостовых сооружений. Результаты исследования предлагается применять в расчетах гибридных стоечных опор мостовых сооружений с элементами из композитных материалов. Statement of the problem. The problem of development of a technique of calculation of the load-bearing capacity of the hybrid reinforced concrete racks intended for rack supports of bridge constructions with external composite (fiberglass) covers is explored. Results. Theoretical dependences for identifying the stresses and relative deformations of structural elements of a hybrid rack in the longitudinal and cross directions are formulated. The resulting formulas take into consideration the joint work of a comprehensively compressed concrete core with an anisotropic fiberglass shell, but do not account for the force and environmental effects directly on the composite shell. Conclusions. The resulting theoretical dependences of the operation of the elements of the hybrid rack enable us to develop a method for calculating the load-bearing capacity of hybrid racks for the supports of bridge structures. It is suggested that the results of the research are applied in calculations of hybrid rack supports of bridge constructions with elements from composite materials.

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Increased load bearing capacity of mechanically joined FRP/metal joints using a pin structured auxiliary joining element

Materials Testing ◽

10.3139/120.111453 ◽

2020 ◽

Vol 62 (1) ◽

pp. 55-60

Author(s):

Per Heyser ◽

Vadim Sartisson ◽

Gerson Meschut ◽

Marcel Droß ◽

Klaus Dröder

Keyword(s):

Bearing Capacity ◽

Load Bearing Capacity ◽

Load Bearing

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Load-Bearing Capacity of Direct Inlay-Retained Fibre-reinforced Composite Fixed Partial Dentures with Different Cross-Sectional Pontic Design

Revista de Chimie ◽

10.37358/rc.17.1.5397 ◽

2017 ◽

Vol 68 (1) ◽

pp. 94-100

Author(s):

Oana Tanculescu ◽

Adrian Doloca ◽

Raluca Maria Vieriu ◽

Florentina Mocanu ◽

Gabriela Ifteni ◽

...

Keyword(s):

Bearing Capacity ◽

Fracture Pattern ◽

Load Bearing Capacity ◽

Cross Sectional ◽

Load Bearing ◽

Reinforced Composite ◽

Polyethylene Fibre

The load-bearing capacity and fracture pattern of direct inlay-retained FRC FDPs with two different cross-sectional designs of the ponticwere tested. The aim of the study was to evaluate a new fibre disposition. Two types of composites, Filtek Bulk Fill Posterior Restorative and Filtek Z250 (3M/ESPE, St. Paul, MN, USA), and one braided polyethylene fibre, Construct (Kerr, USA) were used. The results of the study suggested that the new tested disposition of the fibres prevented in some extend the delamination of the composite on buccal and facial sides of the pontic and increased the load-bearing capacity of the bridges.

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