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Article
Publication date: 7 August 2019

H’mida Hamidane, Ayman Ababneh, Ali Messabhia and Yunping Xi

The purpose of this paper is to develop a method for predicting the chloride ingress into concrete structures, with an emphasis on the low temperature range where freeze-thaw…

219

Abstract

Purpose

The purpose of this paper is to develop a method for predicting the chloride ingress into concrete structures, with an emphasis on the low temperature range where freeze-thaw cycles may cause damage.

Design/methodology/approach

The different phenomena that contribute to the rate and amount of transported chlorides into concrete, i.e., heat transfer, moisture transport and chloride diffusion are modeled using a two-dimensional nonlinear time dependent finite element method. In modeling the chloride transport, a modified version of Fick’s second law is used, in which processes of diffusion and convection due to water movement are taken into account. Besides, the effect of freeze-thaw cycles is directly incorporated in the governing equation and linked to temperature variation using a coupling term that is determined in this study. The proposed finite element model and its associated program are capable of handling pertinent material nonlinearities and variable boundary conditions that simulate real exposure situations.

Findings

The numerical performance of the model was examined through few examples to investigate its ability to simulate chloride penetration under freeze-thaw cycles and its sensitivity to factors controlling freeze-thaw damage. It was also proved that yearly temperature variation models to be used in service life assessment should take into account its cyclic nature to obtain realistic predictions.

Originality/value

The model proved promising and suitable for chloride penetration in cold climates.

Details

International Journal of Building Pathology and Adaptation, vol. 38 no. 1
Type: Research Article
ISSN: 2398-4708

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Article
Publication date: 13 September 2018

Yin Shi-ping, Yu Yulin and Yunping Xi

Textile reinforced concrete (TRC) has excellent bearing capacity and anti-crack and corrosion resistance capacity, which are suitable for strengthening concrete structure under…

180

Abstract

Purpose

Textile reinforced concrete (TRC) has excellent bearing capacity and anti-crack and corrosion resistance capacity, which are suitable for strengthening concrete structure under harsh environments.

Design/methodology/approach

In this thesis, flexural properties of RC beams strengthened with TRC under chloride wet–dry cycles were studied and the effects of the concentration of the salt solution, number of wet–dry cycles, bending stress level and TRC form were considered. Four-point bend loading mode was adopted for the step-loading procedure.

Findings

As the number of wet–dry cycles was relatively few, the trend of the yield and ultimate load with the increasing concentration of salt solution and wet–dry cycles were not obvious. However, the beams under high sustained bending stress level (0.5) had a decrease in the bearing capacity and an increase in mid-span deflection because of the larger degree of the corrosion of steel bars and the weaker bond capacity between the steel bar and concrete. Besides, there was little difference between the precast TRC plate and the casting TRC on beams in terms of the capacity of anti-crack, bearing and deflection.

Research limitations/implications

In this paper, preliminary work has been carried out, but some of the factors were not comprehensive considered, which are inevitable. As the time of dry–wet cycles was short and TRC layer had good anti-crack and anti-permeability performance, smaller chloride ions’ penetration resulted in the corrosion ratio of steel bars to be lower.

Practical implications

It should be noted that under high corrosion rates of the reinforcement, the whole TRC strengthening layer might be spalled off if only the strengthening form at the beam bottom is used, and thus the U-type strengthening form could be considered, which means that the beam is strengthened at both the bottom and side surfaces.

Originality/value

This research only considers the flexural performance of the beams strengthened with TRC in conventional environment, and there is little research on the TRC-strengthened beam under corrosion environment. On the basis of previous research, this paper carried out the experimental study on beams strengthened with TRC under chloride wet–dry cycle environment, and the effects of the concentration of the salt solution, number of wet–dry cycles, bending stress level and TRC form were considered.

Details

Anti-Corrosion Methods and Materials, vol. 65 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 2 January 2025

Modish Kumar and Santosh Kumari

This paper aims to evaluate the available research to identify the factors contributing to the delays in road construction projects. The primary goals of this study are to…

26

Abstract

Purpose

This paper aims to evaluate the available research to identify the factors contributing to the delays in road construction projects. The primary goals of this study are to determine the critical elements that cause delays in road projects, and to investigate the appropriate corrective actions suggested to lessen the delays in road projects. The study also assesses the theoretical background, methodology, limitations and future research prospects suggested in relevant research works related to causes for delays in road construction.

Design/methodology/approach

This study adopted systematic literature review in three steps: collecting relevant literature, descriptive analysis and content analysis. This study used keyword analysis and thematic content analysis on some relevant selected studies. NVivo 12 was used for thematic content analysis utilising description-focused coding, the text was thematically analysed, three other software: MS Excel, VOSviewer and Mendeley were also used for analysis in this study.

Findings

The findings revealed that road projects around the world experienced delays and the reasons for delays are many. After the analysis of literature, number of factors causing delays in road projects were identified, which were then divided into seven broad groups using thematic content analysis. The investigation shows that variations in design and inefficient management of project by contractor including inadequate planning and scheduling are the top two factors of delay. The most frequent suggested corrective measure to reduce delay was employing technically competent employees and contractor should conduct thorough survey on his part, rather than just accepting the survey report at face value.

Research limitations/implications

This review paper is addressing the issues related to delays in road construction projects and suggests remedial measure to reduce them. The paper will be useful for researchers, industry professionals, academician and policy makers concerned with the road construction projects. The study conducted the review of selected relevant articles related to causes of delay in road construction projects for qualitative analysis. The research articles using quantitative methods and studies conducted on other types of infrastructure projects were not included; however, findings from this study may be applicable to other construction projects as well.

Practical implications

The findings of this paper are useful in the fields of economy, industry, academia and public policies. The paper thoroughly examined the factors causing delays in highway projects, offering insights for practitioners to identify best practices and mitigation strategies. These findings can guide investment and policy decisions for highway infrastructure projects, promoting a holistic approach to development. Additionally, this paper can help enhance research methods in studies about delays in road infrastructure projects.

Originality/value

The literature review in the paper used a qualitative method. The causes of road project delays, remedial action, context, methodology and theoretical foundation were all examined in this paper.

Details

Journal of Financial Management of Property and Construction, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1366-4387

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Article
Publication date: 20 October 2011

Li Xi‐can, Yu Tao, Wang Xiao, Yuan Zheng and Shang Xiao‐dong

The purpose of this paper is to establish the grey‐weighted relationship prediction pattern of the soil organic matter content spectral inversion under the uncertainties between…

331

Abstract

Purpose

The purpose of this paper is to establish the grey‐weighted relationship prediction pattern of the soil organic matter content spectral inversion under the uncertainties between soil organic matter contents and spectral characteristics and the theory of grey system.

Design/methodology/approach

At first, according to grey‐weighted distance, a new grey relationship model is presented. Second, in order to make full use of the information of grey relationship sequences, the maximum grey relationship discrimination principle is improved and then the soil organic matter content spectral inversion pattern is put forward based on weighted grey recognition theory. A numeric example of Hengshan County in Shanxi Province is also computed in the last part of the paper.

Findings

The results are convincing: not only that soil organic matter content spectral inversion pattern based on the weighted grey recognition theory is valid, but also the model's prediction accuracy is higher; the sample's average prediction accuracy is 94.917 per cent.

Practical implications

The method exposed in the paper can be used at soil organic matter content hyper‐spectral inversion and even for other similar forecast problems.

Originality/value

The paper succeeds in realising both prediction pattern and application of soil organic matter content hyper‐spectral inversion by using the newest developed theories: weighted grey recognition theory.

Details

Grey Systems: Theory and Application, vol. 1 no. 3
Type: Research Article
ISSN: 2043-9377

Keywords

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