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Article
Publication date: 7 May 2020

Ahmed A. ElShami, Stéphanie Bonnet, Mohamed Hussein Makhlouf, A. Khelidj and N. Leklou

This paper aims to evaluate the ability of Aubepine and Molokhia extract, obtained by cathodic electrochemical treatment (CET), to protect steel rebar against attack by chloride…

249

Abstract

Purpose

This paper aims to evaluate the ability of Aubepine and Molokhia extract, obtained by cathodic electrochemical treatment (CET), to protect steel rebar against attack by chloride ions in environment of reinforced concrete marine structures. The effect of Aubepine and Molokhia extract was investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques.

Design/methodology/approach

This experimental work has achieved particularity to compare the behaviour of two types of treatment (carbon steel treated one time by Aubepine extract and one time by Molokhia extract) submitted to the presence and absence of chloride ions.

Findings

The results obtained show that the extract solution of the plant could serve as an effective inhibitor for the corrosion of steel. Inhibition was found to increase with increasing concentration of Molokhia extract and for Aubepine extract maximum concentration is 1 g/L.

Research limitations/implications

Plant extracts and traditional medicinal herbs have become important as an environmentally acceptable, readily available and renewable source for wide range of inhibitors.

Originality/value

Aubepine and Molokhia extract are novel green plants extract as corrosion inhibiting coating for steel embedded in concrete. Aubepine is a genus of trees in the family Rosaceae and Molokhia is the leaves of Corchorus olitorius. Flavonoids content was found in both of Aubepine and Molokhia extract as green inhibitors for corrosion of metals.

Details

Pigment & Resin Technology, vol. 49 no. 6
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 2 January 2024

Hongjing Dong, Xi Chen, Guangying Yang, Dandan He, Ying Dai and Pengfei He

The purpose of this paper is to obtain a constitutive model of cement-based material in the rheological stage, which owns the different water-cement ratio (w/c) and temperature…

90

Abstract

Purpose

The purpose of this paper is to obtain a constitutive model of cement-based material in the rheological stage, which owns the different water-cement ratio (w/c) and temperature and have a significant impact on the workability of concrete materials.

Design/methodology/approach

It is introduced a modified Arrhenius equation into the Herschel–Bulkley model, which is widely applied in rheological analysis and constructed an ordinary differential equation (ODE) of w/c from the Navier–Stokes equation. By solving the ODE, an approximate constitutive relation of cement-based materials included w/c and temperature is derived. Compared with the experimental results, the present model is validated.

Findings

The shear stress and shear rate curves with different w/c and temperature are simulated by the present method, and the present model can be applied to analyze the changes of apparent viscosity in cement-based material slurry as the w/c and temperature varying.

Originality/value

This work gives a mathematical model, which can effectively approximate the shear stress–shear rate relation with different w/c and temperature in the rheological stage of cement-based material.

Details

Multidiscipline Modeling in Materials and Structures, vol. 20 no. 1
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 28 May 2024

Xiaohu Wen, Xiangkang Cao, Xiao-ze Ma, Zefan Zhang and Zehua Dong

The purpose of this paper was to prepare a ternary hierarchical rough particle to accelerate the anti-corrosive design for coastal concrete infrastructures.

103

Abstract

Purpose

The purpose of this paper was to prepare a ternary hierarchical rough particle to accelerate the anti-corrosive design for coastal concrete infrastructures.

Design/methodology/approach

A kind of micro-nano hydrophobic ternary microparticles was fabricated from SiO2/halloysite nanotubes (HNTs) and recycled concrete powders (RCPs), which was then mixed with sodium silicate and silane to form an inorganic slurry. The slurry was further sprayed on the concrete surface to construct a superhydrophobic coating (SHC). Transmission electron microscopy and energy-dispersive X-ray spectroscopy mappings demonstrate that the nano-sized SiO2 has been grafted on the sub-micron HNTs and then further adhered to the surface of micro-sized RCP, forming a kind of superhydrophobic particles (SiO2/HNTs@RCP) featured of abundant micro-nano hierarchical structures.

Findings

The SHC surface presents excellent superhydrophobicity with the water contact angle >156°. Electrochemical tests indicate that the corrosion rate of mild steel rebar in coated concrete reduces three-order magnitudes relative to the uncoated one in 3.5% NaCl solution. Water uptake and chloride ion (Cl-) diffusion tests show that the SHC exhibits high H2O and Cl- ions barrier properties thanks to the pore-sealing and water-repellence properties of SiO2/HNTs@RCP particles. Furthermore, the SHC possesses considerable mechanical durability and outstanding self-cleaning ability.

Originality/value

SHC inhibits water uptake, Cl- diffusion and rebar corrosion of concrete, which will promote the sustainable application of concrete waste in anti-corrosive concrete projects.

Details

Anti-Corrosion Methods and Materials, vol. 71 no. 5
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 30 May 2019

Muazzam Ghous Sohail, Mohammad Salih, Nasser Al Nuaimi and Ramazan Kahraman

The purpose of this paper is to present the results of a two-year long study carried out in order to evaluate the corrosion performance of mild steel bare bars (BB) and…

347

Abstract

Purpose

The purpose of this paper is to present the results of a two-year long study carried out in order to evaluate the corrosion performance of mild steel bare bars (BB) and epoxy-coated rebar (ECR) in concrete under a simulated harsh environment of chlorides.

Design/methodology/approach

The blocks are subjected to Southern Exposure testing. The electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) and Tafel plot are performed to measure the polarization resistance and corrosion current densities of these rebars. Knife-peel test was performed to assess the adhesion between epoxy and underlying steel after two years of exposure.

Findings

Mild steel BB showed a high corrosion current density of 1.24 µA/ cm2 in Tafel plots and a very low polarization resistance of 4.5 kΩ cm2 in LPR technique, whereas very high charge transfer resistance of 1672 and 1675 kΩ cm2 is observed on ECR and ECR with controlled damage (ECRCD), through EIS technique, respectively. EIS is observed to be a suitable tool to detect the defects in epoxy coatings. After two years of immersion in 3.89 percent NaCl solution, the mild steel BB were severely corroded and a considerable weight loss was observed, whereas under heavy chloride attack, ECR showed no deterioration of epoxy coating and neither any corrosion of underlying steel. Results of this study show that the durability of reinforced concrete (RC) structures with respect to corrosion could be enhanced by using ECR, especially in harsh climatic conditions.

Originality/value

The corrosion performance of mild steel and ECR in concrete under a simulating splash zone environment is evaluated. EIS was used to evaluate the health of epoxy and corrosion state of underneath steel rebars. EIS was able to detect the defects in epoxy. The durability of RC structures could be enhanced in harsh climate regions by using ECR.

Details

International Journal of Building Pathology and Adaptation, vol. 37 no. 5
Type: Research Article
ISSN: 2398-4708

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Article
Publication date: 14 March 2016

Ridha Mazouzi, Ahmed Kellaci and Abdelkader Karas

– This paper aims to study the effect of piston skirt design parameters on the dynamic characteristics of a piston–cylinder contact.

350

Abstract

Purpose

This paper aims to study the effect of piston skirt design parameters on the dynamic characteristics of a piston–cylinder contact.

Design/methodology/pproach

This paper focuses on an analysis of the piston dynamic response. The oil-film pressure and the structural deformation were approximated, respectively, by finite difference method and finite element method.

Findings

The results show that the design parameters such as clearance, offset and the axial location of piston pin have a great influence on the dynamics of the piston and hence on the piston slap phenomenon and the frictional power loss.

Originality/value

All the results mainly focus on the slap noise of the engine and can be used in the piston–liner development at the development of the engine.

Details

Industrial Lubrication and Tribology, vol. 68 no. 2
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 20 August 2024

Amira A.K. Hachem, Jamal M. Khatib and Mohamad Ezzedine El Dandachy

This paper aims to investigate the bond strength of metakaolin-based geopolymer mortar with cement mortar.

34

Abstract

Purpose

This paper aims to investigate the bond strength of metakaolin-based geopolymer mortar with cement mortar.

Design/methodology/approach

The mortar-mortar bond strength is assessed by slant shear and split tensile tests; pure shear strength is evaluated by Mohr’s criterion for result validation. Metakaolin-based geopolymer mortar is cast over the cured cement mortar specimen with two levels of surface roughness: smooth or grooved interface. The influence of the alkaline solution to metakaolin ratio on geopolymer bond strength is studied. Compressive strength, ultrasonic pulse velocity, permeability and flow table tests are also performed.

Findings

The paper’s findings are highlighted as follows: (1) strong mortar-mortar bond properties achieved for geopolymer mortar in all tests and conditions and validated by Mohr’s criterion and pure shear, (2) a lower alkaline solution to metakaolin ratio achieves higher bond strength to Portland cement mortar and (3) geopolymer mortar has higher compressive strength and ultrasonic pulse velocity than cement mortar at all curing ages; additionally, it is more flowable and less permeable.

Practical implications

The full replacement of Portland cement with metakaolin, a more sustainable cementitious material, will contribute to the decarbonization of the construction industry.

Originality/value

Limited research has been carried out on the bond strength of metakaolin-based geopolymer mortar to Portland cement mortar. Also, computing the pure shear using Mohr’s circle criterion of metakaolin-based geopolymer to validate the results can be considered original.

Details

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

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Article
Publication date: 20 May 2024

Mugahed Amran and Ali Onaizi

Low-carbon concrete represents a new direction in mitigating the global warming effects caused by clinker manufacturing. Utilizing Saudi agro-industrial by-products as an

53

Abstract

Purpose

Low-carbon concrete represents a new direction in mitigating the global warming effects caused by clinker manufacturing. Utilizing Saudi agro-industrial by-products as an alternative to cement is a key support in reducing clinker production and promoting innovation in infrastructure and circular economy concepts, toward decarbonization in the construction industry. The use of fly ash (FA) as a cement alternative has been researched and proven effective in enhancing the durability of FA-based concrete, especially at lower replacement levels. However, at higher replacement levels, a noticeable impediment in mechanical strength indicators limits the use of this material.

Design/methodology/approach

In this study, low-carbon concrete mixes were designed by replacing 50% of the cement with FA. Varying ratios of nano-sized glass powder (4 and 6% of cement weight) were used as nanomaterial additives to enhance the mechanical properties and durability of the designed concrete. In addition, a 10% of the mixing water was replaced with EMs dosage.

Findings

The results obtained showed a significant positive impact on resistance and durability properties when replacing 10% of the mixing water with effective microorganisms (EMs) broth and incorporating nanomaterial additives. The optimal mix ratios were those designed with 10% EMs and 4–6% nano-sized glass powder additives. However, it can be concluded that advancements in eco-friendly concrete additive technologies have made significant contributions to the development of sophisticated concrete varieties.

Originality/value

This study focused at developing nanomaterial additives from Saudi industrial wastes and at presenting a cost-effective and feasible solution for enhancing the properties of FA-based concrete. It has also been found that the inclusion of EMs contributes effectively to enhancing the concrete's resistance properties.

Details

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

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Article
Publication date: 3 March 2022

Rabab M. Nasser and Nora M. Masmali

Plant development and use as green corrosion inhibitors are already recognized as one of the most environmentally friendly and effective protocols. In recent years, efforts have…

222

Abstract

Purpose

Plant development and use as green corrosion inhibitors are already recognized as one of the most environmentally friendly and effective protocols. In recent years, efforts have been made to find green corrosion inhibitors as an alternative to synthetic inhibitors for metals in acid medium. This paper aims to report the investigation of use of aqueous extracts of Tamarindus Indica as green inhibitors for corrosion of metals within different circumstances.

Design/methodology/approach

The use of Tamarindus Indica extracts (leaves, stem, fruit pulp and fruit husk) as corrosion inhibitors for mild steel and aluminum in different mediums (HCl, H2SO4, formic acid and citric acid) at different temperatures was investigated.

Findings

The inhibitory efficiency of Tamarindus Indica extracts increases with increasing concentration and decreases with increasing temperature. Langmuir is the adsorption isotherm, and the extract (inhibitor) is a mixed-type inhibitor (physisorption and chemisorption).

Practical implications

Tamarindus extracts (leaves, stem, fruit pulp and fruit husk) are effective inhibitors and can be used to protect metals from corrosion at different circumstances.

Originality/value

To the best of the authors’ knowledge, this is the first review that discusses the use of Tamarindus Indica extracts as corrosion inhibitors for metals.

Details

Anti-Corrosion Methods and Materials, vol. 69 no. 3
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 2 August 2021

Abdelaziz Logbi, Mohamed Mani, Toufik Choungara and Abdelouahed Kriker

This paper aims to study the effect of mineral additions on the mortars’ physical, mechanical and durability properties. Two local mineral additions, considered inert, are chosen…

53

Abstract

Purpose

This paper aims to study the effect of mineral additions on the mortars’ physical, mechanical and durability properties. Two local mineral additions, considered inert, are chosen: limestone fillers from North-East of Algeria and natural dune sand from Algerian desert areas.

Design/methodology/approach

Two local additions are finely crushed to a fineness greater or equal to that of the used cement and incorporated into the mortars with predetermined rates; (0, 10%, 15% and 20%) compared to the cement weight to examine their effects on the mortars’ properties at different ages. Two conservation environments are chosen: freshwater as a neutral area and rising water table as an aggressive area to appreciate the effect of the two additions on physical and mechanical properties and durability.

Findings

The results showed the beneficial effect of these additions on compactness, mechanical resistance and durability toward the rising water table. The results have also allowed us to make an experimental comparison between the limestone addition which is commonly used in the Algerian cement industry and the dune sand, which is not yet well explored and exploited.

Originality/value

The added value of this study is the use of crushed dune sand which is a local addition of southern Algeria for improving the resistance of mortars and concrete toward the aggressiveness of rising water table which presents a major problem for the infrastructure of civil and public construction.

Details

World Journal of Engineering, vol. 20 no. 1
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 11 April 2021

Tarek Hadji, Salim Guettala and Michèle Quéneudec

The purpose of this paper is to present the modeling of statistical variation of experimental data using the design of experiments method to optimize the formulation of a high…

171

Abstract

Purpose

The purpose of this paper is to present the modeling of statistical variation of experimental data using the design of experiments method to optimize the formulation of a high performance concrete (HPC) using materials that are locally available in Algeria. For this, two mineral additions (natural pozzolana and limestone filler [LF]) were used. Both additions are added by substitution of cement up to 25%. To better appreciate the effect of replacing a part of cement by natural pozzolana and LF and to optimize their combined effect on the characteristics of HPC, an effective analytical method is therefore needed to reach the required objective.

Design/methodology/approach

The experimental part of the study consisted of substituting a portion of cement by various proportions of these additions to assess their effects on the physico-mechanical characteristics of HPC. A mixture design with three factors and five levels was carried out. The JMP7 software was used to provide mathematical models for the statistical variation of measured values and to perform a statistical analysis. These models made it possible to show the contribution of the three factors and their interactions in the variation of the response.

Findings

The mixture design approach made it possible to visualize the influence of LF and pozzolanic filler (PF) on the physico-mechanical characteristics of HPC, the developed models present good correlation coefficients (R2 = 0.82) for all studied responses. The obtained results indicated that it is quite possible to substitute a part of cement with LF and PF in the formulation of a HPC. Thanks to the complementary effect between the two additions, the workability could be improved and the strengths drop could be avoided in the short, medium and long term. The optimization of mixture design factors based on the mathematical models was carried out to select the appropriate factors combinations; a good agreement between the experimental results and the predicted results was obtained.

Originality/value

The coefficient of PF in Cs28 model is closer to that of LF than in Cs7 model, thanks to the complementary effect between LF and PF at the age of 28 days. It was found that the optimal HPC14 concrete (10%LF–5%PF) provides the best compromise between the three responses. It is also worth noting that the use of these two local materials can reduce the manufacturing costs of HPC and reduce carbon dioxide emissions into the atmosphere. This can be an important economic and environmental alternative.

Details

World Journal of Engineering, vol. 18 no. 5
Type: Research Article
ISSN: 1708-5284

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