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Article
Publication date: 1 May 2002

António A.R. Henriques, Francisco Calheiros and Joaquim A. Figueiras

A contribution to the definition of a novel safety format for the design of concrete structures based on non‐linear methods of analysis is the main purpose of this work. A…

1009

Abstract

A contribution to the definition of a novel safety format for the design of concrete structures based on non‐linear methods of analysis is the main purpose of this work. A brief discussion of design formats proposed by codes of practice is introduced. Probabilistic analyses of current concrete frames are performed and the corresponding results are used as a basis to derive simplified and coherent practical rules. The analyses have been carried out taking into account the non‐linear material behaviour and the variability of the structural parameters by simulation of probabilistic density functions. A simple procedure is proposed to evaluate the structural safety of concrete frame structures. Mean values are recommended to characterise the material properties to be used in the analysis and a global safety factor is defined to evaluate the structural design resistance.

Details

Engineering Computations, vol. 19 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 31 August 2022

Aya Qatawna, Rabab Allouzi and Samih Qaqish

The primary objective of this study is to produce one-way slabs made of LWFC with low density and sufficient compressive strength suitable for structural purpose then…

Abstract

Purpose

The primary objective of this study is to produce one-way slabs made of LWFC with low density and sufficient compressive strength suitable for structural purpose then investigate their flexural behavior under various types of reinforcement and thickness of the slab and the influence of addition of PP fibers reinforcement on the mechanical behavior of reinforced concrete slabs. The specimens were tested using four-point loading. The results concerning load capacity, deflection and failure mode and crack pattern for each specimen were obtained. Also, an analytical investigation of PP fiber and GFG contribution on the flexural behavior of foamed concrete slabs is studied to investigate the significant role of PP fiber on the stress distribution in reinforced foam concrete and predict the flexural moment capacity.

Design/methodology/approach

The materials used in this study are cement, fine aggregate (sand), water, PP fibers, foaming agent, chemical additives if required, steel reinforcing rebars and glass fiber grid. The combination of these constituent materials will be used to produce foamed concrete in this research Then this study will present the experimental program of one-way foamed concrete slabs including slabs reinforced with GFR grids and another with steel reinforcements. The slabs will be tested in the laboratory under static loading conditions to investigate their ultimate capacities. The flexural behavior is to the interest of the slabs reinforced with GFR grids reinforcements in comparison with that of one with steel reinforcing rebars. Three groups are considered. (1) Group I: two slabs of PP fiber foamed concrete with minimum required reinforcements. (2) Group II: two slabs of PP fiber foamed concrete with glass fiber grids. (3) Group III: two slabs of PP fiber foamed concrete with the minimum required reinforcements and glass fiber grids.

Findings

The experimental results proved the effectiveness and efficiency of this the new system in producing a low density of concrete below 1900 kg/m3 had a corresponding strength of about 17 MPa at least. Besides, the presence of PP fibers had a noticeable improvement on the flexural strength values for all the examined slabs. It was found that the specimens reinforced with steel reinforcement mesh carried higher flexural capacity compared to these reinforced with GFG only. The specimens reinforced with GFG exhibited the lowest flexural capacity due to GFG separation from the concrete substrate. Also, an analytical investigation to predict the flexural strength of all tested specimens was carried out. The analytical results were agreed with the experimental results. Therefore, LWFC can be used as a substitute lightweight concrete material for the production of structural concrete applications in the construction industries today.

Research limitations/implications

Foamed concrete is a wide field to discuss. To achieve the objectives of the project, the study is focused on the foamed concrete with the following limitations: (1) because the aim of this research is to produce foamed concrete suitable for structural purposes, it is decided to produce mixes within the density range 1300–1900 kg/m3. (2) Simply-supported slabs are of considered. (3) This study also looks out by using GFR and without it.

Originality/value

The main objectives of this study were producing structural foamed concrete slabs and investigate their flexural response for residential uses.

Details

International Journal of Building Pathology and Adaptation, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2398-4708

Keywords

Article
Publication date: 1 July 2005

A.E. Richardson

Seeks to examine the bond strength of a large range of structural polypropylene fibres, as used in concrete, to determine the most effective fibre capable of transmitting…

1936

Abstract

Purpose

Seeks to examine the bond strength of a large range of structural polypropylene fibres, as used in concrete, to determine the most effective fibre capable of transmitting load (N/mm2) between fibre and cement within the concrete matrix.

Design/methodology/approach

Following fibre selection characterised by the highest bond strength, determined from a series of pull out tests, BS flexural tests were carried out using high bond strength fibres (40 mm × 0.9 mm diameter used at 6 kg/m3) to determine whether or not structural polypropylene fibres had any effect on the ultimate flexural strength of fibre‐reinforced concrete, when compared with the plain control sample. Fibre orientation, type of rupture failure mode and post‐crack performance were examined.

Findings

Even structural fibre dispersion was found to be best achieved with the use of monofilament polypropylene fibres (19 mm × 22 micron used at 0.9 × kg/m3) in addition to the 6 kg/m3 structural fibre dose. Structural polypropylene fibres were found not to provide additional flexural strength however, they did provide post‐crack control, limiting the crack width with subsequent enhanced durability that in turn will provide lower life cycle costs.

Practical implications

In addition to increased durability the use of fibre reinforcement negates the need to place steel reinforcement bars.

Originality/value

Investigates the ambiguity in literature between claims made by different investigators regarding the effects of polypropylene fibres on compressive and flexural strengths.

Details

Structural Survey, vol. 23 no. 3
Type: Research Article
ISSN: 0263-080X

Keywords

Article
Publication date: 11 May 2020

Arka Ghosh, David John Edwards, M. Reza Hosseini, Riyadh Al-Ameri, Jemal Abawajy and Wellington Didibhuku Thwala

This research paper adopts the fundamental tenets of advanced technologies in industry 4.0 to monitor the structural health of concrete beam members using cost-effective…

Abstract

Purpose

This research paper adopts the fundamental tenets of advanced technologies in industry 4.0 to monitor the structural health of concrete beam members using cost-effective non-destructive technologies. In so doing, the work illustrates how a coalescence of low-cost digital technologies can seamlessly integrate to solve practical construction problems.

Design/methodology/approach

A mixed philosophies epistemological design is adopted to implement the empirical quantitative analysis of “real-time” data collected via sensor-based technologies streamed through a Raspberry Pi and uploaded onto a cloud-based system. Data was analysed using a hybrid approach that combined both vibration-characteristic-based method and linear variable differential transducers (LVDT).

Findings

The research utilises a novel digital research approach for accurately detecting and recording the localisation of structural cracks in concrete beams. This non-destructive low-cost approach was shown to perform with a high degree of accuracy and precision, as verified by the LVDT measurements. This research is testament to the fact that as technological advancements progress at an exponential rate, the cost of implementation continues to reduce to produce higher-accuracy “mass-market” solutions for industry practitioners.

Originality/value

Accurate structural health monitoring of concrete structures necessitates expensive equipment, complex signal processing and skilled operator. The concrete industry is in dire need of a simple but reliable technique that can reduce the testing time, cost and complexity of maintenance of structures. This was the first experiment of its kind that seeks to develop an unconventional approach to solve the maintenance problem associated with concrete structures. This study merges industry 4.0 digital technologies with a novel low-cost and automated hybrid analysis for real-time structural health monitoring of concrete beams by fusing several multidisciplinary approaches into one integral technological configuration.

Details

International Journal of Building Pathology and Adaptation, vol. 39 no. 2
Type: Research Article
ISSN: 2398-4708

Keywords

Article
Publication date: 8 July 2014

Giuseppina Uva, Francesco Porco, Andrea Fiore and Mauro Mezzina

The purpose of this paper is to collect the numerical elaboration of resistances measured on cubes made during the concrete casting and on cores extracted after the…

Abstract

Purpose

The purpose of this paper is to collect the numerical elaboration of resistances measured on cubes made during the concrete casting and on cores extracted after the completion of the structure, for the concrete used in the construction of the “Esaro” Dam facilities (Cosenza, Italy). In addition to the statistical treatment of the sample, aimed at assessing the analytical congruence with the homogeneous classes provided in the design, the influence of compaction degree on in place strength value was qualitatively evaluated.

Design/methodology/approach

The reliability of the concrete during the construction phases was evaluated by two analytical control types according to Italian and European technical rules: “production controls” based on statistical processing of resistance values; “laying controls” that serve to assess the compaction degree with a statistical approach.

Findings

Results highlighted in the assessing of compliance checks of the mixture, the fundamental relation between statistical approach and concrete laying control. They become important when is necessary to quantify, especially in the case of great infrastructure, the gap between “potential” and “structuralconcrete.

Originality/value

The advantage obtained by controlling the compaction degree in the construction phase is unquestionable. Specifically, it might allow a reduction of the drilling cores, and so minor structural damage, especially for relatively recent structures favouring extensive non-destructive tests.

Details

Structural Survey, vol. 32 no. 3
Type: Research Article
ISSN: 0263-080X

Keywords

Article
Publication date: 20 April 2015

Sergiu Andrei Baetu, A H Barbat and Ioan Petru Ciongradi

The purpose of this paper is to investigate a dissipative reinforced concrete structural wall that can improve the behavior of a tall multi-storey building. The main…

Abstract

Purpose

The purpose of this paper is to investigate a dissipative reinforced concrete structural wall that can improve the behavior of a tall multi-storey building. The main objective is to evaluate the damage of a dissipative wall in comparison with that of a solid wall.

Design/methodology/approach

In this paper, a comparative nonlinear dynamic analysis between a dissipative wall and a solid wall is performed by means of SAP2000 software and using a layer model. The solution to increase the seismic performance of a reinforced concrete structural wall is to create a slit zone with short connections. The short connections are introduced as a link element with multi-linear pivot hysteretic plasticity behavior. The behavior of these short connections is modeled using the finite element software ANSYS 12. In this study, the authors propose to evaluate the damage of reinforced concrete slit walls with short connections using seismic analysis.

Findings

Using the computational model created in the second section of the paper, a seismic analysis of a dissipative wall from a multi-storey building was done in the third section. From the results obtained, the advantages of the proposed model are observed.

Originality/value

A simple computational model was created that consume low processing resources and reduces processing time for a dynamic pushover analysis. Unlike other studies on slit walls with short connections, which are focussed mostly on the nonlinear dynamic behavior of the short connections, in this paper the authors take into consideration the whole structural system, wall and connections.

Details

Engineering Computations, vol. 32 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 16 August 2013

Thomas Gernay and Mohamed Salah Dimia

The paper aims to give an insight into the behaviour of reinforced concrete columns during and after the cooling phase of a fire. The study is based on numerical…

Abstract

Purpose

The paper aims to give an insight into the behaviour of reinforced concrete columns during and after the cooling phase of a fire. The study is based on numerical simulations as these tools are frequently used in structural engineering. As the reliability of numerical analysis largely depends on the validity of the constitutive models, the development of a concrete model suitable for natural fire analysis is addressed in the study.

Design/methodology/approach

The paper proposes theoretical considerations supported by numerical examples to discuss the capabilities and limitations of different classes of concrete models and eventually to develop a new concrete model that meets the requirements in case of natural fire analysis. Then, the study performs numerical simulations of concrete columns subjected to natural fire using the new concrete model. A parametric analysis allows for determining the main factors that affect the structural behaviour in cooling.

Findings

Failure of concrete columns during and after the cooling phase of a fire is a possible event. The most critical situations with respect to delayed failure arise for short fires and for columns with low slenderness or massive sections. The concrete model used in the simulations is of prime importance and the use of the Eurocode model would lead to unsafe results.

Practical implications

The paper includes implications for the assessment of the fire resistance of concrete elements in a performance‐based environment.

Originality/value

The paper provides original information about the risk of structural collapse during cooling.

Details

Engineering Computations, vol. 30 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

Open Access
Article
Publication date: 12 April 2022

Hüseyin Emre Ilgın, Markku Karjalainen and Sofie Pelsmakers

This study examined data from 13 international tall residential timber building case studies to increase our understanding of the emerging global trends.

Abstract

Purpose

This study examined data from 13 international tall residential timber building case studies to increase our understanding of the emerging global trends.

Design/methodology/approach

Data were collected through literature surveys and case studies to examine the architectural, structural and constructional points of view to contribute to knowledge about the increasing high-rise timber constructions globally.

Findings

The main findings of this study indicated that: (1) central cores were the most preferred type 10 of core arrangements; (2) frequent use of prismatic forms with rectilinear plans and regular extrusions were identified; (3) the floor-to-floor heights range between 2.81 and 3.30 m with an average of 3 m; (4) the dominance of massive timber use over hybrid construction was observed; (5) the most used structural system was the shear wall system; (6) generally, fire resistance in primary and secondary structural elements exceeded the minimum values specified in the building codes; (7) the reference sound insulation values used for airborne and impact sounds had an average of 50 and 56 dB, respectively.

Originality/value

There is no study in the literature that comprehensively examines the main architectural and structural design considerations of contemporary tall residential timber buildings.

Details

International Journal of Building Pathology and Adaptation, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2398-4708

Keywords

Article
Publication date: 31 October 2018

Sepani Senaratne, Olivia Mirza, Gregory Lambrousis and Alessandro Fernandez-Soncini

The use of recycled aggregates (RA) has been explored to lead to a more sustainable future. The paper investigates on a sustainable concrete mix incorporating steel fibres…

Abstract

Purpose

The use of recycled aggregates (RA) has been explored to lead to a more sustainable future. The paper investigates on a sustainable concrete mix incorporating steel fibres (SF) and RA to provide an alternative to traditional natural aggregate concrete for structural applications. This paper aims to explore the feasibility of combining RA and SF in structural applications in terms of strength, cost and industry perspectives.

Design/methodology/approach

A mixed research approach is established with two phases. Phase 1 aims to identify an optimum material combination that satisfies the structural strength requirements and to identify the costs in its optimum combination. Phase 2 involves qualitative interviews with key industry parties to explore their perspective and identify various enablers and barriers for this material.

Findings

The optimum combination of 30 per cent RA replacement and 0.3 SF volume content has been identified through laboratory testing. It was noted that there would be a direct additional cost because of SF addition. However, when other benefits such as reduction in transportation costs and landfill dumping fees were considered, an overall cost saving could be achieved. Consequently, the key industry practitioners’ perspectives for this material have been gathered through qualitative interviews. Several enablers and barriers were identified through these interviews.

Originality/value

Even though, there are various research attempts on improving RA for structural purpose by adding different additives, a holistic study that incorporate cost effects and the industry perspectives was lacking and is addressed in this current study. In particular, industry perspectives lead to refocus research directions and get closer to the realisation of a sustainable construction industry.

Details

Journal of Engineering, Design and Technology, vol. 16 no. 6
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 10 November 2022

Nursyamsi Nursyamsi, Johannes Tarigan, Muhammad Aswin, Badorul Hisham Abu Bakar and Harianto Hardjasaputra

Damage to reinforced concrete (RC) structural elements is inevitable. Such damage can be the result of several factors, including aggressive environmental conditions…

Abstract

Purpose

Damage to reinforced concrete (RC) structural elements is inevitable. Such damage can be the result of several factors, including aggressive environmental conditions, overloading, inadequate design, poor work execution, fire, storm, earthquakes etc. Therefore, repairing and strengthening is one way to improve damaged structures, so that they can be reutilized. In this research, the use of an ultra high-performance fibre-reinforced concrete (UHPFRC) layer is proposed as a strengthening material to rehabilitate damaged-RC beams. Different strengthening schemes pertaining to the structural performance of the retrofitted RC beams due to the flexural load were investigated.

Design/methodology/approach

A total of 13 normal RC beams were prepared. All the beams were subjected to a four-point flexural test. One beam was selected as the control beam and tested to failure, whereas the remaining beams were tested under a load of up to 50% of the ultimate load capacity of the control beam. The damaged beams were then strengthened using a UHPFRC layer with two different schemes; strip-shape and U-shape schemes, before all the beams were tested to failure.

Findings

Based on the test results, the control beam and all strengthened beams failed in the flexural mode. Compared to the control beam, the damaged-RC beams strengthened using the strip-shape scheme provided an increase in the ultimate load capacity ranging from 14.50% to 43.48% (or an increase of 1.1450 to 1.4348 times), whereas for the U-shape scheme beams ranged from 48.70% to 149.37% (or an increase of 1.4870–2.4937 times). The U-shape scheme was more effective in rehabilitating the damaged-RC beams. The UHPFRC mixtures are workable, as well easy to place and cast into the formworks. Furthermore, the damaged-RC beams strengthened using strip-shape scheme and U-shape scheme generated ductility factors of greater than 4 and 3, respectively. According to Eurocode8, these values are suitable for seismically active regions. Therefore, the strengthened damaged-RC beams under this study can quite feasibly be used in such regions.

Research limitations/implications

Observations of crack patterns were not accompanied by measurements of crack widths due to the unavailability of a microcrack meter in the laboratory. The cost of the strengthening system application were not evaluated in this study, so the users should consider wisely related to the application of this method on the constructions.

Practical implications

Rehabilitation of the damaged-RC beams exhibited an adequate structural performance, where all strengthened RC beams fail in the flexural mode, as well as having increment in the failure load capacity and ductility. So, the used strengthening system in this study can be applied for the building construction in the seismic regions.

Social implications

Aside from equipment, application of this strengthening system need also the labours.

Originality/value

The use of sand blasting on the surfaces of the damaged-RC beams, as well as the application of UHPFRC layers of different thicknesses and shapes to strengthen the damaged-RC beams, provides a novel innovation in the strengthening of damaged-RC beams, which can be applicable to either bridge or building constructions.

Details

Construction Innovation , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1471-4175

Keywords

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