Advanced Concrete Structures in Civil Engineering

A topical collection in Buildings (ISSN 2075-5309). This collection belongs to the section "Building Structures".

Viewed by 44298

Editors

Department of Civil Engineering and Environmental Management, School of Computing, Engineering and Built Environment, Glasgow Caledonian University, Glasgow G4 0BA, UK
Interests: design, analysis and modelling of concrete, timber and steel structures; construction materials technology; dynamic performance of structures; tests on mechanical properties and structural performances of construction materials under loading and extreme environmental conditions (e.g., fire)
School of Civil Engineering, Dalian University of Technology, Dalian 116024, China
Interests: design, analysis and modelling of concrete structures; concrete fracture mechanics and its application in engineering; rock–concrete interfacial fracture; tests on mechanical properties and structural performances of concrete under various conditions

Topical Collection Information

Dear Colleagues,

We would like to warmly welcome you to submit your latest research work on design, construction, analysis, testing, monitoring and repair of concrete structures in civil engineering to this Topical Collection entitled “Advanced Concrete Structures in Civil Engineering” for the MDPI journal Buildings. The following topics are recommended, but your papers need not be limited to these:

  • Structural design of concrete buildings and other civil engineering works
  • Applications of high performance high strength concrete materials to structures
  • Advanced construction technology of concrete structures
  • Experimental investigations on concrete structures
  • Numerical simulations of concrete structures under various loading and environmental conditions
  • Development of concrete design standards
  • Serviceability issues of concrete structures under dynamic loading
  • Grand concrete structures other than buildings
  • Strengthening and repair of concrete structures
  • Interactions between concrete buildings and foundations
  • Monitoring and inspecting of concrete structures

Prof. Dr. Binsheng (Ben) Zhang
Prof. Dr. Wei (David) Dong
Collection Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the collection website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Buildings is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • concrete structures
  • structural design
  • HPC for structures
  • construction technology
  • experimental testing
  • numerical simulations
  • design standards
  • serviceability
  • strengthening

Published Papers (21 papers)

2023

Jump to: 2022, 2021

20 pages, 13209 KiB  
Article
Experimental and Numerical Study on the Seismic Performances of Reinforcement-Embedded RC Column-to-Precast Cap Beams with Socket Connections
by Wenqiang Peng, Wenliang Lu, Sitian Liu, Yong Liu, Linfeng Xu and Fenglin Li
Buildings 2023, 13(9), 2367; https://doi.org/10.3390/buildings13092367 - 17 Sep 2023
Viewed by 787
Abstract
Accelerated bridge construction (ABC) has attracted much attention in China as a new and efficient construction method. However, the seismic performance of the connections between precast piers and other structures limits the application of ABC in medium and high seismic zones. In this [...] Read more.
Accelerated bridge construction (ABC) has attracted much attention in China as a new and efficient construction method. However, the seismic performance of the connections between precast piers and other structures limits the application of ABC in medium and high seismic zones. In this paper, a quasi-static test was conducted to investigate the seismic performance differences between a cap–column socket connection (PSC) specimen, which reinforced an embedded RC column-to-precast cap beam with a socket connection, and a cast-in-place (CIP) cap–column specimen. A fiber-based finite element model that considers bond slippage between the connection reinforcement and wet joint concrete is proposed. The numerical simulation results compared with the experimental results show an error of about 12% in peak bearing capacity and about 2% in initial stiffness. The experimental and numerical results show that the PSC specimen demonstrates comparable seismic performance to the CIP specimen. Experimental results verified that the finite element model in this paper is adequate to predict the seismic responses of a precast column with a reinforcement-embedded socket connection. A reinforcement-embedded RC column-to-precast cap beam with socket connection can be an effective solution for construction in medium and high seismic areas. Full article
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23 pages, 6531 KiB  
Article
Constitutive Model of FRP Tube-Confined Alkali-Activated Slag Lightweight Aggregate Concrete Columns under Axial Compression
by Xinyu Zhang, Pang Chen, Hui Wang, Changchun Xu, Hao Wang and Longliang Zhang
Buildings 2023, 13(9), 2284; https://doi.org/10.3390/buildings13092284 - 08 Sep 2023
Cited by 1 | Viewed by 570
Abstract
Fiber reinforced polymer (FRP), as a novel type of composite material, has been extensively employed in structural strengthening and composite structures. The FRP tube-confined alkali-activated slag lightweight aggregate concrete column (FRP-AASLAC) can effectively improve the utilization rate of slag, reduce carbon emissions, reduce [...] Read more.
Fiber reinforced polymer (FRP), as a novel type of composite material, has been extensively employed in structural strengthening and composite structures. The FRP tube-confined alkali-activated slag lightweight aggregate concrete column (FRP-AASLAC) can effectively improve the utilization rate of slag, reduce carbon emissions, reduce structural self-weight, and improve structural ductility. Therefore, the axial compressive properties of FRP-AASLAC were studied in this paper. The influences of the type of FRP, FRP thickness and the content of lightweight aggregate on the failure modes, bearing capacities, deformation properties and constitutive relationships of FRP-AASLAC were revealed. The results indicate that the constitutive relationships of FRP-AASLAC show double broken line patterns without obvious softening sections. The restraining effect of FRP on lightweight aggregate concrete is higher than that on ordinary concrete as lightweight aggregate concrete has lower strength and more easily undergoes lateral expansion under external loads. Models for compressive strength, peak compressive strain and constitutive relationship for FRP-AASLAC are proposed. Full article
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13 pages, 7823 KiB  
Article
Evaluation of Ultra-High-Performance Concrete Columns at High Temperatures after 180 Days of Curing
by Roberto Christ, Lucas Rafael Lerner, Hinoel Z. Ehrenbring, Fernanda Pacheco, Fabricio L. Bolina, Giovana Poleto, Augusto Masiero Gil and Bernardo F. Tutikian
Buildings 2023, 13(9), 2254; https://doi.org/10.3390/buildings13092254 - 05 Sep 2023
Cited by 1 | Viewed by 637
Abstract
Ultra-high-performance concrete (UHPC) is a material that has high compactness, low porosity, and high mechanical strength, with especially high tensile strength. Due to these characteristics, the behavior of the material when exposed to high temperatures is debatable. The high amount of fibers in [...] Read more.
Ultra-high-performance concrete (UHPC) is a material that has high compactness, low porosity, and high mechanical strength, with especially high tensile strength. Due to these characteristics, the behavior of the material when exposed to high temperatures is debatable. The high amount of fibers in the mixture, which makes UHPC present a high tensile strength, is seen as one of the arguments for the good performance of the material when exposed to high temperatures. The objective of this study was to evaluate the behaviors of ultra-high-performance concrete columns with hybrid steel and polypropylene fibers and no loose reinforcements when subjected to elevated temperatures after 180 days of curing. The exposure of concrete with a low age, less than 90 days, to high temperatures results in greater damage to the concrete due to spalling, and because of this, this study sought to evaluate the UHPC with a higher age. Two columns were manufactured with a cross-section of 250 mm × 250 mm and a height of 2800 mm. A heating regime followed the heating curve of standard ISO 834-1. The physical characteristics of the samples were evaluated during and after exposure to high temperatures with measurements of the decreases in the cross-section and surface aspect. Effects on the compressive strength, modulus of elasticity, and apparent density were evaluated with cylindrical test bodies of 100 mm in diameter and 200 mm in height. These samples were cured for 180 days, subjected to the same heating regime, and evaluated after cooling. The results showed an increase in the compressive strength with an increasing temperature up to a factor of 30% at a temperature of 400 °C. The modulus of elasticity and apparent density decreased gradually as the temperature increased, with maximum decreases of 29% and 6%, respectively. Throughout heating, audible cracks were heard from the columns because of spalling. The spalling frequency peaked at an oven temperature of 600 °C, and testing was suspended at 78 min after the complete rupture of a column section. On average, 46.5% of the column cross-sections suffered from spalling. Full article
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26 pages, 6165 KiB  
Article
Determination of Final Strand Slips of Prestressed Precast Hollow-Core Slabs Subjected to Flexural Load Using Machine Learning Algorithms
by Sadi Ibrahim Haruna, Yasser E. Ibrahim, Musa Adamu and Omar Shabbir Ahmed
Buildings 2023, 13(8), 2013; https://doi.org/10.3390/buildings13082013 - 07 Aug 2023
Cited by 1 | Viewed by 1215
Abstract
Precast prestressed concrete hollow-core slabs (HCUs) are structural elements with less self-weight, providing improved structural effectiveness in withstanding the straining action and allowing for a long span. This study investigated the additional strand slips and developed machine learning (ML) models for evaluating the [...] Read more.
Precast prestressed concrete hollow-core slabs (HCUs) are structural elements with less self-weight, providing improved structural effectiveness in withstanding the straining action and allowing for a long span. This study investigated the additional strand slips and developed machine learning (ML) models for evaluating the final strand slips (Śf) of the precast HCUs. Two groups of HCUs, with nominal widths of 1.2 m and 0.55 m, were subjected to flexural loading conditions. One sample from each group was selected to form composite specimens by casting a concrete topping slab, and the restrain mechanism was attached at the ends of the additional HCU specimens. The experimental datasets used to train the ML models, including the support vector machine (SVM), multi-linear regression (MLR), and improved eliminate particle swamp optimization hybridized artificial neural network (IEPANN) models for the prediction of Śf. The efficacy of the IEPANN model compared to the nonlinear predictive models was evaluated, and the performances of the developed ML models were checked using the evaluation matrices. The results indicated that the prestressing strands with relatively higher initial strand slips may result in larger additional slips during flexural loading. The restraining mechanism and cast-in-place topping slab influenced the additional strand slip rate. The hybridized IEPANN model outperformed other classical models in estimating the additional slips with the R2 values greater than 0.9 in the two modelling stages, indicating the efficacy of the IEPANN compared to the nonlinear predictive modes. Full article
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17 pages, 2743 KiB  
Article
Predictive Model of Temperature Regimes of a Concrete Gravity Dam during Construction: Reducing Cracking Risks
by Nikolai Alekseevich Aniskin and Trong Chuc Nguyen
Buildings 2023, 13(8), 1954; https://doi.org/10.3390/buildings13081954 - 31 Jul 2023
Cited by 1 | Viewed by 675
Abstract
In consideration of the mild climatic conditions of North Vietnam with average monthly air temperatures ranging from 15 °C in winter to 26.5 °C, this study analyzes the regulation of the temperature regime and thermally stressed state of a concrete gravity dam made [...] Read more.
In consideration of the mild climatic conditions of North Vietnam with average monthly air temperatures ranging from 15 °C in winter to 26.5 °C, this study analyzes the regulation of the temperature regime and thermally stressed state of a concrete gravity dam made of rolled concrete. Despite the favorable weather conditions, there remains a risk of thermal cracking, necessitating the presentation of crack-formation models from different countries to assess and mitigate the risk of cracking through the adjustment of construction conditions. The study has developed a predictive model for the temperature regime and thermally stressed state of a layer-by-layer concrete mass under the given construction conditions using the factor-analysis method. Regression equations were then derived from the factorial experiment to quantify the responses of the maximum temperature and maximum stress in the concrete mass. The numerical finite-element method using the Midas Civil software package was employed to calculate the temperature regime and thermally stressed state of the concrete mass. To validate the mathematical predictive model, it was tested on the Ban Lai gravity dam in North Vietnam. The dam, which was constructed from rolled concrete and stands 56 m tall, was selected as the object in this practical example. The results obtained from applying the predictive model were compared to the results obtained from numerical calculations of the dam under construction, as well as the findings from field observations. These results were found to be in good agreement, indicating the effectiveness of the predictive model. Furthermore, an evaluation of the potential for temperature cracking of the concrete during the construction period was conducted. Full article
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26 pages, 9714 KiB  
Article
Investigation of Circular Hollow Concrete Columns Reinforced with GFRP Bars and Spirals
by Afaq Ahmad, Alireza Bahrami, Omar Alajarmeh, Nida Chairman and Muhammad Yaqub
Buildings 2023, 13(4), 1056; https://doi.org/10.3390/buildings13041056 - 17 Apr 2023
Cited by 3 | Viewed by 1314
Abstract
Glass fiber-reinforced polymer (GFRP) reinforcements are useful alternatives to traditional steel bars in concrete structures, particularly in vertical structural elements such as columns, as they are less prone to corrosion, and impart increasing strength and endurance of buildings. There is limited research on [...] Read more.
Glass fiber-reinforced polymer (GFRP) reinforcements are useful alternatives to traditional steel bars in concrete structures, particularly in vertical structural elements such as columns, as they are less prone to corrosion, and impart increasing strength and endurance of buildings. There is limited research on the finite element analysis (FEA) of the structural behavior of hollow glass fiber-reinforced polymer reinforced concrete (GFRPRC) columns. The hollow portion can be used for the service duct and for reducing the self-weight of the members. Numerical analysis of the compressive response of circular hollow concrete columns reinforced with GFRP bars and spirals is performed in this study. This article aims to investigate the axial behavior of hollow GFRP concrete columns and compare it with that of solid steel reinforced concrete (RC) columns as well as hollow steel RC columns. The Abaqus software is used to construct finite element models. After calibration of modeling using an experimental test result as a control model, a parametric study is conducted. The columns with the same geometry, loading, and boundary conditions are analyzed in the parametric study. It is resulted that the hollow GFRP concrete columns provide a greater confinement effect than the solid steel RC columns. The average variation in the ultimate axial load-carrying capacities of the experimental results, from that of the FEA values, is noted to be only 3.87%, while the average difference in the corresponding deformations is 7.08%. Moreover, the hollow GFRP concrete columns possess greater axial load and deformation capacities compared with the solid steel RC columns. Full article
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2022

Jump to: 2023, 2021

12 pages, 5864 KiB  
Article
Structural Behavior of Reinforced Concrete Beams Containing Nanomaterials Subjected to Monotonic and Cyclic Loadings
by Gouda A. Mohamed, Ezzaat A. Sallam and Ahmed N. Elbelacy
Buildings 2022, 12(10), 1620; https://doi.org/10.3390/buildings12101620 - 06 Oct 2022
Viewed by 1521
Abstract
The use of nanomaterials improves the performance of reinforced concrete (RC) beams in terms of cracking load, failure load, and deflection. To further evaluate this improvement, the behavior of RC beams subjected to cyclic loading has to be experimentally investigated. In the present [...] Read more.
The use of nanomaterials improves the performance of reinforced concrete (RC) beams in terms of cracking load, failure load, and deflection. To further evaluate this improvement, the behavior of RC beams subjected to cyclic loading has to be experimentally investigated. In the present study, the effect of adding nanomaterials to RC beams was studied experimentally under monotonic and cyclic loadings. Eight RC beams with the dimensions of 2200 mm × 350 mm × 120 mm were prepared and divided into two groups. Both groups were tested under three-point bending, but one group was tested monotonously whereas the other group was tested cyclically. Each group consisted of four beams. The first beam in each group was tested without adding any nanomaterials. Nanotitanium, nanoaluminum, and nanosilica were added to the concrete mixes of the remaining three to replace 1% of the cement content. The performances of the tested beams were compared in terms of load-deflection curves, failure mode, cracking load, failure load, bending stiffness, toughness, and residual strength ratio (RSR). The results from both monotonic and cyclic loadings indicated better performances when nanotitanium was used. Full article
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17 pages, 4431 KiB  
Article
Effects of Size and Flexural Reinforcement Ratio on Ambient-Cured Geopolymer Slag Concrete Beams under Four-Point Bending
by Hala Mamdouh, Ashraf M. Ali, Mostafa A. Osman, Ahmed F. Deifalla and Nehal M. Ayash
Buildings 2022, 12(10), 1554; https://doi.org/10.3390/buildings12101554 - 28 Sep 2022
Cited by 5 | Viewed by 1872
Abstract
With the rise in cement production required by conventional concrete, CO2 emissions increase, causing pollution to the atmosphere. Geopolymer concrete (GPC) is investigated in the literature as an eco-efficient alternative to conventional concrete (CC). However, most geopolymer studies focus on studying the [...] Read more.
With the rise in cement production required by conventional concrete, CO2 emissions increase, causing pollution to the atmosphere. Geopolymer concrete (GPC) is investigated in the literature as an eco-efficient alternative to conventional concrete (CC). However, most geopolymer studies focus on studying the mechanical properties of GPC, with only limited investigations on the structural performances of structural elements using GPC. The structural behaviors of GPC elements are yet to be completely understood, and there are no current studies on investigating the structural behaviors of geopolymer slag concrete. Thus, this paper investigates the flexural performances of reinforced geopolymer slag concrete beams, focusing on the effects of different beam depths and reinforcement ratios. Five full-scale ambient-cured reinforced geopolymer slag concrete beams were tested under four-point flexure, in addition to one control conventional concrete (CC) beam. The structural performances are evaluated, including the cracking moment, flexural capacity, load–deflection relationship, and crack distribution. The results indicate that the flexural behaviors of GPC beams are comparable to that of the CC beams. Compared to the CC beams, the GPC beams have 7.4% higher flexural moment capacity, 60% lower stiffness, 28% lower ductility, and 18.3% higher toughness. Finally, the Egyptian code of practice ECP 203 and ACI 318 are found to be applicable to safely design under-reinforced GPC flexural beam elements. Full article
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19 pages, 5032 KiB  
Article
Seismic Performance Evaluation of a High-Rise Building with Structural Irregularities
by Huijuan Jia, Yongsheng Song, Xi Chen, Shunqing Liu and Binsheng Zhang
Buildings 2022, 12(9), 1484; https://doi.org/10.3390/buildings12091484 - 18 Sep 2022
Cited by 3 | Viewed by 3164
Abstract
In this study, the seismic performances of a 14-storey office building in Nanjing, China, due to its plan and vertical irregularities in the structural system, were evaluated using the response spectrum method, elastic time history analysis and elastic–plastic time history analysis. In combination [...] Read more.
In this study, the seismic performances of a 14-storey office building in Nanjing, China, due to its plan and vertical irregularities in the structural system, were evaluated using the response spectrum method, elastic time history analysis and elastic–plastic time history analysis. In combination of these three methods, the storey drifts and elastic–plastic states of typical structural members under three levels of earthquakes were determined to verify the robustness of the structural design program. The damage states of typical structural members at some sensitive positions were estimated and evaluated under rare earthquakes. Consequently, all structural members were within the scope of elastic performances under the actions of frequent earthquakes. The maximum displacements and storey drifts satisfied the requirements of the design codes within the scope of elastic or elastic–plastic deformations. The induced damages could reach “moderate damage” states, satisfying the requirements for the expected performances by the codes. The consequences indicated that the design scheme and critical parameters for the building structure satisfied the requirements of seismic performances from the codes. Full article
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18 pages, 11226 KiB  
Article
Comparative Analysis of Mechanical Performance of Flat Slabs with Reverse and Conventional Column Caps
by Mosong Gong, Bowen Yang, Zhengrong Jiang and Huishan Mo
Buildings 2022, 12(8), 1139; https://doi.org/10.3390/buildings12081139 - 01 Aug 2022
Viewed by 1307
Abstract
Compared with the conventional column caps, the reverse column caps that are used for slab-column joint of basement roof can improve the clearance of the basement while ensuring structural safety, and they are hidden in the covering soil without affecting the appearance and [...] Read more.
Compared with the conventional column caps, the reverse column caps that are used for slab-column joint of basement roof can improve the clearance of the basement while ensuring structural safety, and they are hidden in the covering soil without affecting the appearance and use of upper surface of flat slabs. In this paper, four finite element models, which are loaded by column-end displacement-control mechanism, are established. These models are used to investigate the mechanical performance of slab-column joint for flat slabs with reverse and conventional column caps. The obtained numerical results were thoroughly analysed, indicating that the load-carrying capacity performances of flat slabs with conventional column caps are much higher than their counterparts with reverse column caps, but flat slabs with conventional column caps possess lower mechanical ductility. Moreover, the reverse column caps were found to exhibit a severe damage at ultimate load; therefore, transverse stirrups were distributed into the reverse and conventional column caps for the purpose of comparison. The comparison results revealed that the ultimate load of the slab-column joints with reverse column cap can be increased by 2.4% by arranging transverse stirrups in column cap, but the ductility is decreased by 13.4%. For the slab-column joints with conventional column cap, the ultimate load is decreased by 10.0% and the ductility is decreased by 1.6% when transverse stirrups are arranged in column cap. Therefore, arrangement of transverse stirrups in column cap should be determined based on the actual situation in the flat slab system with reverse column cap, and it is not recommended to arrange transverse stirrups in column cap in the flat slab system with conventional column cap. Full article
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17 pages, 5863 KiB  
Article
Effect of the Progressive Failure of Shear Connectors on the Behavior of Steel-Reinforced Concrete Composite Girders
by Fahad Alsharari, Alaa El-Din El-Sisi, Mohammed Mutnbak, Hani Salim and Ayman El-Zohairy
Buildings 2022, 12(5), 596; https://doi.org/10.3390/buildings12050596 - 04 May 2022
Cited by 10 | Viewed by 3196
Abstract
Pre-stressed steel-concrete composite beams are widely used in bridges around the world. Loads during the service life of bridges may cause failure in the form of fracture in the studs near the ends of the bridge girders. The effect of stud failure on [...] Read more.
Pre-stressed steel-concrete composite beams are widely used in bridges around the world. Loads during the service life of bridges may cause failure in the form of fracture in the studs near the ends of the bridge girders. The effect of stud failure on the residual static capacity and residual fatigue life of composite girders is not well investigated. Therefore, this study presents numerical investigations into the effects of the progressive failure of stud shear connectors on the residual static performance and remaining fatigue life of post-tensioned steel-concrete composite beams. The Finite Element (FE) model was validated using existing experimental work. Moreover, the effects of the progressive failure of stud shear connectors on the steel-concrete interface slippage, shear stress range, and compressive and tensile strains were investigated. The behavior of the composite girders in terms of the estimated fatigue life and residual capacity was inversely affected by the number of fractured studs. The AASHTO theoretical equation conservatively estimated the remaining fatigue life until 15% of the rows were removed and then the FE model predicted fewer remaining fatigue cycles than the theoretical equation. Until 15% of the rows were removed, the strengthened sample had a better response in terms of the stress range, tensile and compressive strains, and residual capacity. After that, both the strengthened and non-strengthened samples exhibited similar responses to the failure of studs. Subsequently, the positive effects of the post-tensioning vanish as the end studs fail. Therefore, designers should pay special attention to the ends of post-tensioned composite beams where the local failure of studs is expected. Full article
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16 pages, 4379 KiB  
Article
Numerical Simulations on the Flexural Responses of Rubberised Concrete
by Ali Al-Balhawi, Nura Jasim Muhammed, Haider Amer Mushatat, Hadi Naser Ghadhban Al-Maliki and Binsheng Zhang
Buildings 2022, 12(5), 590; https://doi.org/10.3390/buildings12050590 - 02 May 2022
Cited by 2 | Viewed by 1950
Abstract
The increase in world population has led to a significant increase in the numbers of cars and used tyres. These tyres must be disposed of on an ongoing basis as a result of their consumption or deterioration. This can result in negative effects [...] Read more.
The increase in world population has led to a significant increase in the numbers of cars and used tyres. These tyres must be disposed of on an ongoing basis as a result of their consumption or deterioration. This can result in negative effects on the environment that must be preserved, especially from those materials, i.e., these waste materials are difficult to dispose of without special treatments. Hence, extensive experimental investigations and numerical simulations need to be conducted to use and recycle these wastes by exploring the possibility of using them as alternative ingredients in construction materials. For example, waste rubber pieces can be used as one of the main components of concrete. In this study, the main aim was to numerically simulate the flexural behaviours of rubberised concrete under the influence of an applied vertical loading with different contents of added rubbers by using the commercial finite element software ANSYS. The obtained numerical results were compared with the experimental results of a previous study and showed a good agreement with the deflections and moduli of rupture, with the variances from 2–7% in the deflections. However, the differences in the moduli of rupture varied between 5% and 9%. Finally, the statistical analyses indicated that these numerical mean values and standard deviations were acceptable and were very close to the experimental values. Full article
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13 pages, 4076 KiB  
Article
Shear Strength of Headed Stud Connectors in Self-Compacting Concrete with Recycled Coarse Aggregate
by Samoel Mahdi Saleh and Fareed Hameed Majeed
Buildings 2022, 12(5), 505; https://doi.org/10.3390/buildings12050505 - 19 Apr 2022
Cited by 5 | Viewed by 1828
Abstract
This study investigated the use of self-compacting concrete (SCC) made with recycled coarse aggregates (RCAs), which represents a trend of producing environment-friendly concrete, integrated with hot-rolled steel sections by means of headed stud shear connectors in composite structures. Therefore, thirty-six push-out test specimens [...] Read more.
This study investigated the use of self-compacting concrete (SCC) made with recycled coarse aggregates (RCAs), which represents a trend of producing environment-friendly concrete, integrated with hot-rolled steel sections by means of headed stud shear connectors in composite structures. Therefore, thirty-six push-out test specimens were examined to assess the shear strength and behavior of the headed stud connectors embedded in RCA-SCC, with the concrete compressive strength, stud diameter, and RCA ratio as the main variables. Four ratios of RCAs ranging from 0 to 60% were used to produce concrete with three different compressive strengths (25, 33, and 40 MPa) for each one. It was found that the use of SCC with RCAs had a negative effect on the shear strength of headed stud connectors. This negative effect could be reduced by increasing the concrete compressive strength and/or the stud diameter. Similarly, a reduction in the shear stiffness of the tested specimens was inversely proportional to the RCA ratio, while the ultimate slip was directly proportional to the RCA ratio. An evaluation of the test results was made by comparing them with those determined by Eurocode 4 and AASHTO LRFD. Full article
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18 pages, 9743 KiB  
Article
Behavior of One-Way Reinforced Concrete Slabs with Polystyrene Embedded Arched Blocks
by Ali Hussein Ali Al-Ahmed, Falah Hasan Ibrahim, Abbas AbdulMajeed Allawi and Ayman El-Zohairy
Buildings 2022, 12(3), 331; https://doi.org/10.3390/buildings12030331 - 10 Mar 2022
Cited by 2 | Viewed by 2637
Abstract
This study presents experimental and numerical investigations on seven one-way, reinforced concrete (RC) slabs with a new technique of slab weight reduction using polystyrene-embedded arched blocks (PEABs). All slabs had the same dimensions, steel reinforcement, and concrete compressive strength. One of these slabs [...] Read more.
This study presents experimental and numerical investigations on seven one-way, reinforced concrete (RC) slabs with a new technique of slab weight reduction using polystyrene-embedded arched blocks (PEABs). All slabs had the same dimensions, steel reinforcement, and concrete compressive strength. One of these slabs was a solid slab, which was taken as a control slab, while the other six slabs were cast with PEABs. The main variables were the ratio of the length of the PEABs to the length of the slab (lp/L) and the ratio of the height of the PEABs to the total slab depth (hP/H). The minimum decrease in the ultimate load capacity was about 6% with a minimum reduction in the slab weight of 15%. In contrast, the maximum decrease in the ultimate load capacity was about 24% with a maximum reduction in the slab weight of 40%. Moreover, the mode of failure changed from flexure to shear failure, especially for those slabs with an lP/L ratio equal to one. The geometric and material non-linearity was adopted in the proposed finite element (FE) model to simulate the slabs with PEABs using Abaqus software. Good agreement was obtained between the developed FE and experimental results. Full article
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19 pages, 6496 KiB  
Article
Assessment of Strength Reduction Factor on Concrete Moment Frames According to the New Venezuelan Seismic Code
by Ramón Mata-Lemus, Ahmad Idrees-Rustom, Javier Sánchez-Rodríguez, Ronald Torres-Moreno, Eduardo Nuñez-Castellanos and Guillermo Bustamante-Laissle
Buildings 2022, 12(3), 255; https://doi.org/10.3390/buildings12030255 - 22 Feb 2022
Cited by 2 | Viewed by 1896
Abstract
Nonlinear static analysis is a validated tool for the seismic evaluation of existing and new structures, specifically for reinforced concrete buildings. In order to assess the performance of reinforced concrete frames designed according to the new Venezuelan seismic code, configurations of low-, medium-, [...] Read more.
Nonlinear static analysis is a validated tool for the seismic evaluation of existing and new structures, specifically for reinforced concrete buildings. In order to assess the performance of reinforced concrete frames designed according to the new Venezuelan seismic code, configurations of low-, medium-, and high-rise concrete buildings are subjected to 20 different load patterns considering the nonlinear behavior according to FEMA P695. A total of 140 concrete frame models were analyzed using modal response spectrum analysis and nonlinear static pushover analysis. The parameters considered for analyzing the models were the response reduction factor (R), the overstrength factor (RΩ), and the ductility factor (Rµ). The results showed a performance controlled by ductile failure mechanisms in low-rise models unlike combined failure mechanisms with columns with plastic hinge in high-rise models. Reduction factor values between 4 and 14 were obtained. In addition, the pushover curves were affected by the load patterns; therefore, it was necessary to identify the representative patterns, refusing the rest of the patterns. A statistical adjustment was performed using a log-normal distribution. The strength reduction factor specified in the new Venezuelan code was higher than the values obtained for the 95% confidence levels according to the distribution assumed in the reinforced concrete frames models. Finally, the strength reduction factor more representative is R = 4. Full article
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19 pages, 8699 KiB  
Article
Flexural Behavior of RC Beams Using Fe-Based Shape Memory Alloy Rebars as Tensile Reinforcement
by Ki-Nam Hong, Yeong-Mo Yeon, Sang-Won Ji and Sugyu Lee
Buildings 2022, 12(2), 190; https://doi.org/10.3390/buildings12020190 - 08 Feb 2022
Cited by 10 | Viewed by 1720
Abstract
Recently, various studies for the use of Fe-based shape memory alloy (Fe-SMA) in the construction field have been widely conducted. However, most of the studies for using Fe-SMA are carried out for applying Fe-SMA for strengthening deteriorated structures. However, if Fe-SMA is used [...] Read more.
Recently, various studies for the use of Fe-based shape memory alloy (Fe-SMA) in the construction field have been widely conducted. However, most of the studies for using Fe-SMA are carried out for applying Fe-SMA for strengthening deteriorated structures. However, if Fe-SMA is used as a reinforcement for new structures, the disadvantages of conventional prestressed concrete can be effectively solved. Therefore, in this work, an experimental study was conducted to evaluate the flexural behavior of concrete beams in which Fe-SMA rebars were used as tensile reinforcement. For the study, ten specimens were constructed with the consideration of the cross-sectional area and activation of Fe-SMA rebars as experimental variable. Activation of the Fe-SMA rebars by electrical resistance heating applied an eccentric compressive force to the specimen to induce camber. The camber increased by an average of 0.093 mm as the cross-sectional area of the Fe-SMA rebar increased by 100 mm2. It was also confirmed through the four-point bending tests that the initial crack loads of the activated specimens were 47.6~112.8% greater than those of the nonactivated specimens. However, the ultimate strength of the activated specimens showed a slight difference of 3% to those of the nonactivated specimens. Therefore, it was confirmed that the effect of Fe-SMA activation on the ultimate strength of specimens was negligible. Full article
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21 pages, 6599 KiB  
Article
Structural Efficiency of Non-Prismatic Hollow Reinforced Concrete Beams Retrofitted with CFRP Sheets
by Ahmad Jabbar Hussain Alshimmeri, Esraa Kamal Jaafar, Lina Abdulsalam Shihab, Hadi Naser Ghadhban Al-Maliki, Ali Al-Balhawi and Binsheng Zhang
Buildings 2022, 12(2), 109; https://doi.org/10.3390/buildings12020109 - 23 Jan 2022
Cited by 7 | Viewed by 3676
Abstract
Non-prismatic reinforced concrete (RC) beams are widely used for various practical purposes, including enhancing architectural aesthetics and increasing the overall thickness in the support area above the column, which gives high assurance to services that this will not result in the distortion of [...] Read more.
Non-prismatic reinforced concrete (RC) beams are widely used for various practical purposes, including enhancing architectural aesthetics and increasing the overall thickness in the support area above the column, which gives high assurance to services that this will not result in the distortion of construction features and can reduce heights. The hollow sections (recess) can also be used for the maintenance of large structural sections and the safe passage of utility lines of water, gas, telecommunications, electricity, etc. They are generally used in large and complex civil engineering works like bridges. This study conducted a numerical study using the commercial finite element software ANSYS version 15 for analysing RC beams, hollow longitudinally sectioned and retrofitted with carbon fibre reinforced polymers (CFRPs), which were subjected to concentrated vertical loads. The numerical analysis results on the simulated beam models were in excellent agreements with the previous experimental test results. This convergence was confirmed by a statistical analysis, which considered the correlation coefficients, individual arithmetic means and standard deviations for all the calculated deflections of the simulated beam models. A proposed numerical simulation model with the hypotheses can be considered suitable for modelling the behaviours of simple supported non-prismatic RC beams under vertical concentrated loads. The numerical results showed that altering the cross-section from solid to hollow could reduce the load carrying capacities of the beams by up to 53% and increase the corresponding deflections by up to 40%, respectively. Using steel pipes for making recesses could enhance the loading capacity by up to 56%, increase the ductility, and reduce the corresponding deflections by up to 30%, respectively. Finally, it was found that bonding the CFRP sheets in the lower middle tensile areas of the hollow beams could improve the resistance and reduce the deformations by up to 27%. The failure patterns for all the numerical models were shear failure. The cylinder compressive strength could be used as a mechanical parameter for modelling and assessing the structural behaviours of the beam models, as its increase could improve the load carrying capacities and reduce the deflections by 30–50%. Full article
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22 pages, 3173 KiB  
Article
Multifactorial Chloride Ingress Model for Reinforced Concrete Structures Subjected to Unsaturated Conditions
by Enrico Zacchei and Emilio Bastidas-Arteaga
Buildings 2022, 12(2), 107; https://doi.org/10.3390/buildings12020107 - 23 Jan 2022
Cited by 9 | Viewed by 2703
Abstract
The attack of chloride ions is one of the most important factors affecting reinforced concrete (RC) durability. Chloride ingress into concrete is usually studied by assuming constant diffusivity and constant surface chloride concentration. However, these two approximations could badly estimate the chloride concentration [...] Read more.
The attack of chloride ions is one of the most important factors affecting reinforced concrete (RC) durability. Chloride ingress into concrete is usually studied by assuming constant diffusivity and constant surface chloride concentration. However, these two approximations could badly estimate the chloride concentration in RC structures and then the lifetime assessment. Several factors influence the chloride concentration and ingress mechanisms in the convection area. In this paper, a new multifactorial and multiphase model to account for some effects on chloride surface concentrations in the convection zone is proposed. 136 values have been collected to identify the position and the chloride concentration in the border between the diffusion and convection zones. In addition, a time-dependent multifactorial diffusivity is considered. Diffusivity, which is the key parameter of the mechanical diffusion accounts in this paper for the water/cement ratio, chloride binding, temperature, concrete age, internal humidity, concrete deformation, and damage. The surface chloride model considers environment humidity, temperature, superficial concrete irregularities, and convection area of concrete. Advanced numerical solutions have been carried out to consider space and time dependencies in the model. Results show that the error function-based solutions could underestimate the chloride concentration C for periods < 10 years and for concrete depths > 4.0 cm in comparison with the proposed model. Full article
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2021

Jump to: 2023, 2022

16 pages, 4608 KiB  
Article
Test and Evaluation of the Flexural Properties of Reinforced Concrete Beams with 100% Recycled Coarse Aggregate and Manufactured Sand
by Changyong Li, Tongsheng Liu, Hao Fu, Xiaoyan Zhang, Yabin Yang and Shunbo Zhao
Buildings 2021, 11(9), 420; https://doi.org/10.3390/buildings11090420 - 19 Sep 2021
Cited by 8 | Viewed by 2204
Abstract
Although studies have been performed on the recycled aggregate made of waste concrete for the production of new concrete, the new concrete with 100% recycled coarse aggregate and manufactured sand (abbreviated as RAMC) still needs to be researched for structural applications. In this [...] Read more.
Although studies have been performed on the recycled aggregate made of waste concrete for the production of new concrete, the new concrete with 100% recycled coarse aggregate and manufactured sand (abbreviated as RAMC) still needs to be researched for structural applications. In this paper, an experimental study was performed on seven groups, including fourteen reinforced RAMC beams under the simply supported four-point loading test, considering the factors of the strength of RAMC and the reinforcement ratio of longitudinal tensile rebars. Based on the test results, the cracking resistance, the bearing capacity, the crack width, the flexural stiffness and the mid-span deflection of reinforced RAMC beams in bending are discussed and examined by using the formulas of conventional reinforced concrete beams. Results show that an obvious effect of reinforcement ratio was present, while less so was that of the strength of RAMC. With the comparison of predicted values by the formulas of conventional reinforced concrete beams, the reinforced RAMC beams decreased cracking resistance by about 20%, increased crack width by about 15% and increased mid-span deflection by about 10%, although the same bearing capacity can be reached. The results directly relate to the lower tensile strength of RAMC which should be further improved. Full article
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16 pages, 7959 KiB  
Article
Structural Efficiency of Hollow Reinforced Concrete Beams Subjected to Partial Uniformly Distributed Loading
by Hadi Naser Ghadhban Al-Maliki, Ali Al-Balhawi, Ahmad Jabbar Hussain Alshimmeri and Binsheng Zhang
Buildings 2021, 11(9), 391; https://doi.org/10.3390/buildings11090391 - 03 Sep 2021
Cited by 9 | Viewed by 4589
Abstract
Reinforced concrete (RC) beams containing a longitudinal cavity have become an innovative development and advantage for economic purposes of light-weight members without largely affecting their resistance against the applied loads. This type of openings can also be used for maintenance purposes and usage [...] Read more.
Reinforced concrete (RC) beams containing a longitudinal cavity have become an innovative development and advantage for economic purposes of light-weight members without largely affecting their resistance against the applied loads. This type of openings can also be used for maintenance purposes and usage space of communication lines, pipelines, etc. RC beams are primarily loaded in the plane of the members, which are two-dimensional in a plane stress state and the dominant structural behaviours include bending, shear, or combination of both. In the present study, six numerical models of RC beams with and without openings were simulated by using commercial finite element software ANSYS to evaluate the structural behaviours of those beam models under the partial uniformly distributed load. Different parameters were assessed, including opening dimensions and shear reinforcement ratios. The obtained numerical results were analysed and verified and were found very close to those obtained from the experimental investigations in the literature. The increase of shear reinforcement ratio could enhance the flexural and shear capacities of the RC beams, and the results also showed that some models sustained flexural failure while the others sustained failure of combined bending and shear. Full article
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17 pages, 14977 KiB  
Article
Research on Bonding Performance of Anchorage Caisson Foundation with Different Contact Surfaces and Grouting Bed
by Tiesuo Geng, Shuanghua Chen, Liuqun Zhao and Zhe Zhang
Buildings 2021, 11(8), 365; https://doi.org/10.3390/buildings11080365 - 19 Aug 2021
Cited by 1 | Viewed by 1997
Abstract
In view of the first domestic offshore suspension bridge with caisson foundation, this paper mainly studies the bonding properties between underwater pre-filled aggregate grouting bed and anchorage caisson foundation. Through the test, the cohesive force of adding ordinary concrete between the anchorage caisson [...] Read more.
In view of the first domestic offshore suspension bridge with caisson foundation, this paper mainly studies the bonding properties between underwater pre-filled aggregate grouting bed and anchorage caisson foundation. Through the test, the cohesive force of adding ordinary concrete between the anchorage caisson foundation and the grouting bed, the cohesive force of adding paper base asphalt felt between the anchorage caisson foundation and the grouting bed, and the cohesive force of adding geotextile between the anchorage caisson foundation and the grouting bed are measured, respectively. When the contact surface is concrete and geotextile, the fracture form of the specimen was analyzed by numerical simulation, and the AE variation trend of the two specimens have been studied. The results of this article can provide references for other projects. Full article
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