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Article

Virendra Kumar

This paper aims to study the residual test results under uni-axial compression of tie confined pre-damaged normal strength concrete short columns subjected to elevated…

Abstract

Purpose

This paper aims to study the residual test results under uni-axial compression of tie confined pre-damaged normal strength concrete short columns subjected to elevated temperatures.

Design/methodology/approach

The test variables included temperature of exposure, spacing of transverse confining reinforcement and pre-damage level. An experimental program was designed and carried out involving testing of hoop confined concrete cylindrical specimens exposed to elevated temperatures ranging from room temperature to 900 °C.

Findings

The test results indicate that the residual strength, strain corresponding to the peak stress and the post-peak strains of confined concrete are not affected significantly up to an exposure temperature of 300 °C. However, the peak confined stress falls and the corresponding strain increase considerably in the temperature range of 600 to 900 °C. It is shown that an increase in the degree of confinement reinforcement results in an increased residual strength and deformability of pre-damaged confined concrete.

Research limitations/implications

It is applicable in finding the residual strength and strain of the pre-damaged confined concrete in uni-axial compression after exposure to elevated temperature.

Practical implications

The practical implications is that the test result is applicable in finding the residual strengths of pre-damaged confined concrete under uni-axial compression after exposure to elevated temperature.

Social implications

The main aim of the present investigation is to provide experimental data on the residual behaviour of pre-damaged confined concrete subjected to high temperatures.

Originality/value

The results of this study may be useful for developing the guidelines for designing the confinement reinforcement of reinforced concrete columns against the combined actions of earthquake and fire, as well as for designing the retrofitting schemes after these sequential disasters.

Details

Journal of Structural Fire Engineering, vol. 11 no. 1
Type: Research Article
ISSN: 2040-2317

Keywords

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Article

Umesh Sharma, Virendra Kumar, Praveen Kamath, Bhupinder Singh, Pradeep Bhargava, Yogendra Singh, Asif Usmani, Jose Torero, Martin Gillie and Pankaj Pankaj

In present study, a full-scale testing of reinforced concrete (RC) frame sub-assemblage has been investigated under fire subsequent to simulated seismic loading. First…

Abstract

In present study, a full-scale testing of reinforced concrete (RC) frame sub-assemblage has been investigated under fire subsequent to simulated seismic loading. First part of the sequential loading consisted of a quasi-static cyclic lateral loading corresponds to life safety level of structural performance on the test frame. In the second part of the test, a compartment fire was ignited to the pre-damaged test frame for one hour duration simulating fire following earthquake (FFE) scenario. The results showed that the first cracking was observed at the end joints of the roof beams after the frame experienced a 30 mm cyclic lateral displacement. One hour heating and eleven hour cooling was tracked and temperatures were recorded. A knocking sound was heard from the fire compartment after 5 minutes of the fire ignition. An excessive degradation of the concrete material at a number of locations of the frame sub-assemblage was observed during visual inspection after the fire test. The Nondestructive tests (NDT) were also conducted to ascertain the damage in the RC frame at the various stages of loading. The test results developed an understanding of the behaviour of RC frame sub-assemblage in FFE.

Details

Journal of Structural Fire Engineering, vol. 5 no. 3
Type: Research Article
ISSN: 2040-2317

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Article

J.R. Linge

THE application of cemented wires to determine the location of initial failure in static tests on large specimens has been investigated, among others, by R. W. Powell in 1946.

Abstract

THE application of cemented wires to determine the location of initial failure in static tests on large specimens has been investigated, among others, by R. W. Powell in 1946.

Details

Aircraft Engineering and Aerospace Technology, vol. 29 no. 11
Type: Research Article
ISSN: 0002-2667

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Article

Virendra Kumar

The occurrence of multiple hazards in extreme conditions is not unknown nowadays, but the sustainability of the reinforced concrete structures under such scenarios form…

Abstract

Purpose

The occurrence of multiple hazards in extreme conditions is not unknown nowadays, but the sustainability of the reinforced concrete structures under such scenarios form competitive challenges in civil engineering profession. Among all, fire following earthquake (FFE) is categorized under multiple extreme load scenarios which causes sequential damages to the structures. This paper aims to experiment a full-scale RC frame sub-assemblage for the FFE scenario and assess each stage of damage through the nondestructive testing method.

Design/methodology/approach

Two levels of simulated earthquake damages, i.e. immediate occupancy (IO) level and life safety (LS) level of structural performance were induced to the test frame and then, followed by a realistic compartment fire of 1 h duration. Also, the evaluation of damage to the RC frame after the fire subsequent to the earthquake was carried out by obtaining the ultimate capacity of the frame. Ultrasonic pulse velocity and rebound hammer test were conducted to assess the structural endurance of the damaged frame. Cracks were also marked during mechanical damages to the test frame to study the nature of its propagation.

Findings

Careful visual inspection during and after the fire test to the test frame were done. To differentiate between concrete chemically affected by the fire or physically damaged is an important issue. In situ inspection and laboratory tests of concrete components have been performed. Concrete from the test frame was localized with thermo-gravimetric analysis. The UPV results exhibited a sharp decrease in the strength of the concrete material which was also confirmed via the DTA, TGA and TG results. It is important to evaluate the residual capacity of the entire structure under the FFE scenario and propose rehabilitation/retrofit schemes for the building structure.

Research limitations/implications

The heterogeneity in the distribution of the damage has been identified due to variation of fire exposure. The study only highlights the capabilities of the methods for finding the residual capacity of the RC frame sub-assemblage after an occurrence of an FFE.

Originality/value

It is of find kind of research work on full-scale reinforced concrete building. In this, an attempt has been made for the evaluation of concrete structures affected by an FFE through nondestructive and destructive methods.

Details

Journal of Structural Fire Engineering, vol. 10 no. 3
Type: Research Article
ISSN: 2040-2317

Keywords

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Article

L. Woolf

The performance for surface coatings for the protection of both offshore structures and submarine pipelines are probably the most stringent of any outside those of space travel.

Abstract

The performance for surface coatings for the protection of both offshore structures and submarine pipelines are probably the most stringent of any outside those of space travel.

Details

Anti-Corrosion Methods and Materials, vol. 24 no. 5
Type: Research Article
ISSN: 0003-5599

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Article

Wolfgang Siegert

Focuses on the use of biocides to combat the growth of microorganisms in coolant systems and oils. Outlines measures which can limit or prevent mcrobial growth and…

Abstract

Focuses on the use of biocides to combat the growth of microorganisms in coolant systems and oils. Outlines measures which can limit or prevent mcrobial growth and provides a brief summary of the European Biocidal Products Directive.

Details

Industrial Lubrication and Tribology, vol. 54 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

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Article

M.T. Copper, W.H. Thomason and J.D.C. Vardon

The development of the Hutton Field in the UK sector of the North Sea incorporates, for the first time, a buoyant Tension Leg Platform maintained in position by an array…

Abstract

The development of the Hutton Field in the UK sector of the North Sea incorporates, for the first time, a buoyant Tension Leg Platform maintained in position by an array of sixteen tubular steel tension leg strings. To satisfy the stringent design criteria associated with this new generation of offshore oil production facilities, all corrosion control systems have to be effective, reliable and contribute little to structure weight. An intensive review of the various available design options was undertaken, from which emerged the use of aluminium metal sprayed coatings as possibly the optimum method of corrosion control for the tension legs. Since there was limited service data available relating to the performance of sprayed metal coatings in sea water immersion service, a development programme was completed to determine the perfomance characteristics of these coatings under tension leg operating conditions. In parallel, the problems of applying the coatings were addressed since it was considered that, as for all coating systems, correct application is critical to the satisfactory in‐service performance of the coating. The potential advantages of sprayed metal coatings for immersion service in the offshore industry was significant.

Details

Anti-Corrosion Methods and Materials, vol. 33 no. 7
Type: Research Article
ISSN: 0003-5599

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Article

L. Woolf

All anti‐corrosive coatings have a common role of protecting the substrate to which they are applied.

Abstract

All anti‐corrosive coatings have a common role of protecting the substrate to which they are applied.

Details

Anti-Corrosion Methods and Materials, vol. 23 no. 11
Type: Research Article
ISSN: 0003-5599

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Article

Fuyuan Gong, Yuya Takahashi and Koichi Maekawa

This paper aims to propose a multi-scale simulation approach for the concrete macro-mechanical damage caused by mixed micro-pore pressures, such as the coupled…

Abstract

Purpose

This paper aims to propose a multi-scale simulation approach for the concrete macro-mechanical damage caused by mixed micro-pore pressures, such as the coupled alkali–silica reaction (ASR) and freeze-thaw cycles (FTC).

Design/methodology/approach

The micro-physical events are computationally modeled by considering the coupling effect between ASR gel and condensed water in the mixed pressure and motion. The pressures and transport of pore substances are also linked with the concrete matrix deformation at macro-scale through a poro-mechanical approach, and affect each other, reciprocally. Once the crack happens in the nonlinear analysis, both the micro-events (water and gel motion) and the macro mechanics will be mutually interacted. Finally, different sequences of combined ASR and FTC are simulated.

Findings

The multi-chemo mechanistic computation can reproduce complex events in pore structures, and further the macro-damages. The results show that ASR can reduce the FTC expansion for non-air-entrained concrete, but may increase the frost damage for air-entrained concrete. The simulation is examined to bring about the observed phenomena.

Originality/value

This paper numerically clarifies the strong linkage between macro-mechanical deformation and micro-chemo-physical events for concrete composites under coupled ASR and FTC.

Details

Engineering Computations, vol. 35 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

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Article

Lothar Wagner, Mansour Mhaede, Manfred Wollmann, Igor Altenberger and Yuji Sano

The purpose of this paper is to investigate the influence of mechanical surface treatments on the surface layer properties and the fatigue performance of the aircraft…

Abstract

Purpose

The purpose of this paper is to investigate the influence of mechanical surface treatments on the surface layer properties and the fatigue performance of the aircraft alloys Al 7075‐T73 and Ti‐6Al‐4V

Design/methodology/approach

Laser peening without coating (LPwC), shot peening (SP), ultrasonic shot peening (USP) and ball burnishing (BB) were applied and the resulting changes in surface roughness and residual stress‐depth profiles were evaluated. Fatigue performance of both alloys was tested in rotating beam loading (R=−1) on hourglass‐shaped specimens and the results were compared with the electrolytically polished (EP) reference conditions.

Findings

All studied mechanical surface treatments led to pronounced increases in fully reversed fatigue lives and fatigue strengths in both Al 7075‐T73 and Ti‐6Al‐4V.

Originality/value

To the authors' knowledge, this is the first paper that compares fatigue performance of a wide variety of mechanically surface treated conditions in two aircraft alloys.

Details

International Journal of Structural Integrity, vol. 2 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

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