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Kolli M.,Laboratoire des Materiaux Non Metalliques | Madjoubi M.A.,Laboratoire des Materiaux Non Metalliques | Hamidouche M.,Laboratoire des Materiaux Non Metalliques | Bouaouadja N.,Laboratoire des Materiaux Non Metalliques | Fantozzi G.,INSA Lyon
Annales de Chimie: Science des Materiaux | Year: 2010

This work reports the effect of the chemical treatment by HF acid on the strength and the optical transmission of sandblasted glasses. Before treatment, the strength and the optical transmission of the sandblasted glass were respectively 40 MPa and 35.2 %. After treatement with hydrofluoric acid (HF), the strength increases. It reaches the as received glass strength (95 MPa) after 8 hours treatment in 5% HF solution. At the early stage, optical transmission drops, due to the grooving phenomena of the median cracks and scaling along the lateral crack. This drop is followed by a continuous improvement of the optical transmission in relation to the surface state improvement. After 8 hours of treatment in 5% HF, we measured an optical transmission of about 48%. © Lavoisier, Paris.


Rokbi M.,Laboratoire des Materiaux Non Metalliques | Rokbi M.,University of Msila | Herbelot C.,Lille Laboratory of Mechanics | Imad A.,Lille Laboratory of Mechanics | And 3 more authors.
ECCM 2012 - Composites at Venice, Proceedings of the 15th European Conference on Composite Materials | Year: 2012

The aim of this paper is to describe the fracture behavior and failure mechanisms of Alfa fibers and its composites. The used reinforcement consists of Alfa fibers, extracted from the plant Stippa tenacissima from Hodna Region (Algeria). The Alfa fibers are subjected to alkali treatments with NaOH at 1, 5 and 10% for a period of 0, 24, and 48 h at 28°C. The composites reinforced with layers of Alfa random constituent a rate of 40% by weight. We studied the development of the different damage phases using the digital image correlation under static loading of compact tension test (CT). The plane-strain fracture toughness, KR, of different random short Alfa fibers reinforced polyester resin was investigated with the effect of fibers treatment.


Rokbi M.,Laboratoire des Materiaux Non Metalliques | Osmani H.,University Of Msila | Imad A.,Lille Laboratory of Mechanics | Benseddiq N.,Lille Laboratory of Mechanics
Procedia Engineering | Year: 2011

This paper focuses on the study of the effect of chemical treatments of fibers by alkalization on the flexural properties of polyester matrix composite reinforced with natural fibers. The used reinforcement consists of Alfa fiber, extracted from the plant Stippa tenacissima from Hodna Region (Algeria). Alfa fibers are subjected to alkali treatments with NaOH at 1, 5 and 10% for a period of 0, 24, and 48 h to 28 °C. The composites reinforced with layers of Alfa random costituente a rate of 40% by weight. Influence of alkaline treatments on the flexural properties is studied to determine the optimum conditions of alkaline treatment. The experimental results show that the bending behavior of composites made from alkali treated fibers are better compared to the untreated fiber composite, For a fiber processing Alfa 10% NaOH in 24h, the flexural strength and flexural modulus improved by 23 MPa to 57MPa and from 1.16 to 3.04 GPa. However, the flexural properties of composites decreased after alkali treatment with 5% NaOH for 48 h. This is mainly due to the reduction of lignin that binds the cellulose fibrils together. © 2011 Published by Elsevier Ltd.


Benyahia A.,University Of Msila | Merrouche A.,University Of Msila | Rahmouni Z.E.A.,University Of Msila | Rokbi M.,Laboratoire des Materiaux Non Metalliques | And 2 more authors.
Mechanics and Industry | Year: 2014

In this paper, composites based on unsaturated polyester resin reinforced with short Alfa fibers are studied in detail. Alfa fibers have been previously treated with various concentrations NaOH (1, 3, 5, 7%) during 24 h. The influence of alkali treatment on fiber morphology is analyzed. Analysis by FTIR and X-ray diffraction showed physico-chemical changes in Alfa fiber treated surfaces. SEM observations also helped to highlight these changes. The results of static tests on composites showed improvements in tensile and flexural strengths of composites reinforced with the treated fibers, particularly the composite with treated fibers at 7% NaOH. These improvements were about 30% and 50%, respectively, compared to untreated fiber reinforced composite. © 2014 AFM, EDP Sciences.


Chikouche M.D.L.,Oran University of Science and Technology - Mohamed Boudiaf | Merrouche A.,Oran University of Science and Technology - Mohamed Boudiaf | Azizi A.,Ferhat Abbas University Setif | Rokbi M.,Laboratoire des Materiaux Non Metalliques | Walter S.,Upper Alsace University
Journal of Reinforced Plastics and Composites | Year: 2015

In recent years, natural fibres have been experimented to replace glass fibres in reinforcing thermosetting polymer. Since the interfacial adhesion between the raw natural fibres and the polymer matrix are often not adapted to the intended applications, the fibre surface most often requires a preliminary chemical modification. The fibres which were extracted from the Arundo donax L. Plant (called cane fibres), are little studied in the literature of fibre/polymer composites. In the present work, the cane fibres have been treated at constant soaking time with 2-8% NaOH aqueous solutions for 24€‰h. The composite reinforced by 6% NaOH-treated cane fibres, exhibited maximum improvements in tensile and flexural strength by 57% and 45% respectively. A combination of Fourier transform infrared, scanning electron microscopy, X-ray diffraction and moisture absorption techniques has been used for material characterisation. The crystallinity index yields information about fibre modification by NaOH. Such cane fibre composites could become an alternative to existing materials, with interesting tensile and flexural strengths, low cost and less ecological impact. © SAGE Publications.

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