scholarly journals Strength of connections in precast concrete structures

2011 ◽  
Vol 9 (2) ◽  
pp. 241-259 ◽  
Author(s):  
Radomir Folic ◽  
Damir Zenunovic ◽  
Nesib Residbegovic
Keyword(s):  
Reinforced Concrete ◽  
Mathematical Models ◽  
Precast Concrete ◽  
Fracture Mechanisms ◽  
Failure Model ◽  
Rc Structures ◽  
Failure Assessment ◽  
Numerical Research ◽  
Plate Connection ◽  
Monolithic Structures

The available experimental and numerical results of many studies of behavior of reinforced concrete connections for different stages of loading, up to fracture loading, are presented and analyzed in this paper. The problem of beam-column connection (or plate-wall connection) in prefabricated monolithic structures is emphasized. Fracture mechanisms of RC structures, the theoretical basis for their analysis, and the use of fracture mechanics in RC structures were also considered, as well as the mathematical models of prefabricated connections. In order to formulate an adequate mathematical model for calculating the connections, the dominant parameters influencing the behaviour of these connections were analyzed. A failure model for the prefabricated wall - monolithic RC plate connection was formulated. In building the model, the results of implemented experimental and numerical research of prefabricated connection in the MMS system from 2007 were used. Experiences with the implementation of the aforementioned construction system in structures in Tuzla, in the 1980's last century, were additionally used. The proposed mathematical models provide a sufficiently accurate failure assessment of prefabricated reinforced concrete connections.

scholarly journals Development and Application of Precast Concrete Double Wall System to Improve Productivity of Retaining Wall Construction

2020 ◽  
Vol 12 (8) ◽  
pp. 3454
Author(s):  
Seungho Kim ◽  
Dong-Eun Lee ◽  
Yonggu Kim ◽  
Sangyong Kim
Keyword(s):  
Reinforced Concrete ◽  
Precast Concrete ◽  
Retaining Wall ◽  
Rc Structures ◽  
Existing Problems ◽  
Concrete Panels ◽  
Wall Construction ◽  
Construction Efficiency ◽  
Double Wall ◽  
Wall System

The construction of most apartment underground parking lots utilizes reinforced concrete (RC) structures composed mainly of rebar work and formwork. RC structures lower construction efficiency and significantly delay the construction because they require a large number of temporary materials and wooden formwork. In this study, a precast concrete double wall (PCDW) system was developed to address the existing problems of RC structures and to improve the productivity of retaining wall construction. PCDW is a precast concrete (PC) wall in which two thin concrete panels are connected parallel to each other with truss-shaped reinforcement between them. PCDW can contribute to securing integrity, reducing the delay in construction, and improving quality. An overall process for the member design and construction stage of the PCDW system was proposed, and its improvement effects were examined regarding various aspects in comparison to the RC method.

scholarly journals Prospects for the use of solar energy to accelerate the hardening of concrete in the construction of monolithic structures in Russia

2021 ◽  
Vol 284 ◽  
pp. 06001
Author(s):  
David A. Sarkisov ◽  
Boris V. Zhadanovskii ◽  
Sergey A. Sinenko ◽  
Maksim K. Esenov
Keyword(s):  
Reinforced Concrete ◽  
Solar Energy ◽  
Construction Industry ◽  
Precast Concrete ◽  
Energy Resources ◽  
Unit Costs ◽  
Monolithic Structures

This article addresses the issue of solving the problem of using the solar energy, that allows decreasing of the unit costs, or even avoiding using of the traditional energy resources for performance of the concrete in the southern regions of Russian. Researches that were carried out allow developing more contemporary methods of monolithic construction’s concrete curing. Various types of methods of solar energy using in case to produce precast concrete or reinforced concrete items found vast distribution and implementation in construction industry.

Fiber-reinforced concrete in precast concrete applications: Research leads to innovative products

PCI Journal ◽  
2012 ◽  
Vol 57 (3) ◽  
pp. 33-46 ◽  
Author(s):  
Nemkumar Banthia ◽  
Vivek Bindiganavile ◽  
John Jones ◽  
Jeff Novak
Keyword(s):  
Reinforced Concrete ◽  
Precast Concrete ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Innovative Products

Use of Foam Polystyrene Waste in the Conditions of a Reinforced Concrete Products Factory

2020 ◽  
pp. 49-52
Author(s):  
S.E. YANUTINA ◽  
Keyword(s):  
Reinforced Concrete ◽  
Precast Concrete ◽  
Expanded Polystyrene ◽  
Insulation Material ◽  
Design Strength ◽  
Foam Polystyrene ◽  
Secondary Use ◽  
Concrete Blocks ◽  
Polystyrene Waste ◽  
Factory Laboratory

The relevance of research in the factory laboratory of JSC «198 KZHI», which is part of the HC GVSU «Center», is dictated by the need to dispose of foam polystyrene waste that occurs in large quantities when producing the precast concrete. In the production of three-layer external wall panels, polystyrene heatinsulating plates of the PPS 17-R-A brand are used as an effective insulation material. The secondary use of PPS 17-R-A for its intended purpose, as a heater, is not possible. The volume of foam polystyrene produced varies from 25 to 45 m3 per month. Utilization (disposal) of foam polystyrene waste is an expensive undertaking. Its use as a filler in the production of expanded polystyrene blocks was tested in the factory’s laboratory to produce foam polystyrene concrete with specified physical and mechanical characteristics. The results of testing of expanded polystyrene concrete of classes B2.5 and B 7.5 are presented. It is shown that under the conditions of the reinforced concrete factory technology, the production of polystyrene concrete blocks is possible with the achievement of the design strength. The information presented in the article is aimed at motivating specialists who produce recast concrete to the possibility of using foam polystyrene waste for low-rise construction. Keywords: foam polystyrene, ecology, energy efficiency, foam polystyrene concrete, foam polystyrene heat insulation plates, precast concrete.

scholarly journals Degradation Monitoring in Reinforced Concrete with 3D Localization of Rebar Corrosion and Related Concrete Cracking

2021 ◽  
Vol 11 (15) ◽  
pp. 6772
Author(s):  
Charlotte Van Steen ◽  
Els Verstrynge
Keyword(s):  
Reinforced Concrete ◽  
Degradation Mechanism ◽  
Heterogeneous Material ◽  
Corrosion Damage ◽  
Corrosion Process ◽  
Internal Damage ◽  
Rc Structures ◽  
Degradation Monitoring ◽  
Rebar Corrosion ◽  
Width Measurements

Corrosion of the reinforcement is a major degradation mechanism affecting durability and safety of reinforced concrete (RC) structures. As the corrosion process starts internally, it can take years before visual damage can be noticed on the surface, resulting in an overall degraded condition and leading to large financial costs for maintenance and repair. The acoustic emission (AE) technique enables the continuous monitoring of the progress of internal cracking in a non-invasive way. However, as RC is a heterogeneous material, reliable damage detection and localization remains challenging. This paper presents extensive experimental research aiming at localizing internal damage in RC during the corrosion process. Results of corrosion damage monitoring with AE are presented and validated on three sample scales: small mortar samples (scale 1), RC prisms (scale 2), and RC beams (scale 3). For each scale, the corrosion process was accelerated by imposing a direct current. It is found that the AE technique can detect damage earlier than visual inspection. However, dedicated filtering is necessary to reliably localize AE events. Therefore, AE signals were filtered by a newly developed post-processing protocol which significantly improves the localization results. On the smallest scale, results were confirmed with 3D micro-CT imaging, whereas on scales 2 and 3, results were compared with surface crack width measurements and resulting rebar corrosion levels.

scholarly journals A Practical Finite Element Modeling Strategy to Capture Cracking and Crushing Behavior of Reinforced Concrete Structures

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 506 ◽  
Author(s):  
Alexandre Mathern ◽  
Jincheng Yang
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Constitutive Relations ◽  
Fe Analysis ◽  
Rc Beams ◽  
Cracking Behavior ◽  
Concrete Cracking ◽  
Rc Structures ◽  
Nonlinear Fe Analysis ◽  
Modeling Strategy

Nonlinear finite element (FE) analysis of reinforced concrete (RC) structures is characterized by numerous modeling options and input parameters. To accurately model the nonlinear RC behavior involving concrete cracking in tension and crushing in compression, practitioners make different choices regarding the critical modeling issues, e.g., defining the concrete constitutive relations, assigning the bond between the concrete and the steel reinforcement, and solving problems related to convergence difficulties and mesh sensitivities. Thus, it is imperative to review the common modeling choices critically and develop a robust modeling strategy with consistency, reliability, and comparability. This paper proposes a modeling strategy and practical recommendations for the nonlinear FE analysis of RC structures based on parametric studies of critical modeling choices. The proposed modeling strategy aims at providing reliable predictions of flexural responses of RC members with a focus on concrete cracking behavior and crushing failure, which serve as the foundation for more complex modeling cases, e.g., RC beams bonded with fiber reinforced polymer (FRP) laminates. Additionally, herein, the implementation procedure for the proposed modeling strategy is comprehensively described with a focus on the critical modeling issues for RC structures. The proposed strategy is demonstrated through FE analyses of RC beams tested in four-point bending—one RC beam as reference and one beam externally bonded with a carbon-FRP (CFRP) laminate in its soffit. The simulated results agree well with experimental measurements regarding load-deformation relationship, cracking, flexural failure due to concrete crushing, and CFRP debonding initiated by intermediate cracks. The modeling strategy and recommendations presented herein are applicable to the nonlinear FE analysis of RC structures in general.

scholarly journals Statistical and Reliability Study on Shear Strength of Recycled Coarse Aggregate Reinforced Concrete Beams

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3321
Author(s):  
Hyunjin Ju ◽  
Meirzhan Yerzhanov ◽  
Alina Serik ◽  
Deuckhang Lee ◽  
Jong R. Kim
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Construction Material ◽  
Safety Margin ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Rc Structures ◽  
Coarse Aggregates

The consumption of structural concrete in the construction industry is rapidly growing, and concrete will remain the main construction material for increasing urbanization all over the world in the near future. Meanwhile, construction and demolition waste from concrete structures is also leading to a significant environmental problem. Therefore, a proper sustainable solution is needed to address this environmental concern. One of the solutions can be using recycled coarse aggregates (RCA) in reinforced concrete (RC) structures. Extensive research has been conducted in this area in recent years. However, the usage of RCA concrete in the industry is still limited due to the absence of structural regulations appropriate to the RCA concrete. This study addresses a safety margin of RCA concrete beams in terms of shear capacity which is comparable to natural coarse aggregates (NCA) concrete beams. To this end, a database for reinforced concrete beams made of recycled coarse aggregates with and without shear reinforcement was established, collecting the shear specimens available from various works in the existing literature. The database was used to statistically identify the strength margin between RCA and NCA concrete beams and to calculate its safety margin based on reliability analysis. Moreover, a comparability study of RCA beams was conducted with its control specimens and with a database for conventional RC beams.

scholarly journals Experimental testing of medium scale GFRP reinforced concrete frames

2019 ◽  
Vol 289 ◽  
pp. 04004
Author(s):  
George Hopartean ◽  
Ted Donchev ◽  
Diana Petkova ◽  
Costas Georgopoulos ◽  
Mukesh Limbachiya ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Experimental Testing ◽  
Control Sample ◽  
Concrete Frames ◽  
Reinforced Concrete Frames ◽  
Reinforced Polymers ◽  
Rc Structures ◽  
Gfrp Bars ◽  
Glass Frp ◽  
Reversed Cyclic

Fibre reinforced polymers (FRP) have been used as strengthening for existing RC structures for many decades. Lately, there has been a lot of interest in using FRP as internal reinforcement in beams, slabs and columns. One potential area of application could be reinforced concrete frames internally reinforced with GFRP bars. With limited research in this direction, the objective of this publication is to assess the behaviour of glass FRP (GFRP) reinforced concrete frames under reversed cyclic lateral in plane loading and to analyse the seismic performances of such elements. For the purpose of this paper, experimental testing of two 1/3 scaled down frames is conducted in displacement-controlled mode with the loading history according to ACI 374.1-05. The control sample is reinforced with conventional steel reinforcement and the results obtained are compared with the sample reinforced with GFRP bars. In summary, observations on the sample behaviour at specified drift ratio such as load-displacement behaviour, envelope curves and energy dissipation are presented.

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