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Evaluation of physical and mechanical properties of cement-treated base incorporating crushed waste tires

Mezhoud Samy, Badache Hacene

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2023

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Vol. 32, No. 4

305--319

EN

Pavements play a pivotal role in facilitating safe and efficient transportation. However, conventional pavement construction consumes substantial virgin resources, necessitating a shift towards sustainable alternatives. This study explores the integration of crushed waste tires as partial replacements for sand and gravel in cement-treated base (CTB) layers, aiming to enhance pavement sustainability. The CTB mixtures were meticulously formulated and tested for their physical and mechanical properties. Results revealed that while the presence of waste tire aggregates affected the fresh-state rheology, the cured-state performance remained satisfactory, often exceeding normative requirements. Notably, the addition of 10% rubber powder enhanced the mechanical performance of the CTB mixtures and overall exhibited acceptable shrinkage values. The findings offer insights into designing resilient and sustainable pavement systems by using crushed waste tires, aligning with modern infrastructure demands.

2

Impact of recycled aggregate brick on the physical-mechanical and environmental characteristics of cement treated bases

Toumi Youcef, Mezhoud Samy, Boukendakdji Otmane, Hadjadj Moussa

Budownictwo i Architektura

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2023

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Vol. 22, no 3

27--44

EN

Recycled aggregate brick (RAB) constitutes a significant waste stream in developed countries, originating from brick manufacturing and demolition processes. This paper investigates the potential utilization of various sizes of RAB as replacements for natural aggregate (NA) in cement-treated bases (CTB), along with an assessment of their mechanical and environmental properties. The study includes a life cycle analysis to evaluate the environmental impacts of different CTB formulations. The novelty of this study lies in the environmental evaluation of four types of CTB, including natural, recycled, and mixed CTB. The physical and mechanical properties of the recycled brick and natural materials are characterized and compared. Results indicate that recycled brick aggregates, when combined with a cement mixture, can be used as a base and sub-base layer with good mechanical performance. Moreover, environmental analyses demonstrate that recycled aggregate generates fewer impacts than natural aggregates. Consequently, this study suggests that the utilization of recycled aggregates brick in CTB offers a sustainable waste management solution while simultaneously contributing to the reduction of environmental impacts associated with construction activities.

3

Evaluation of Behavior of Hybrid Beam Combining Steel Inverted T-Section and RC Flange

Badache Hacene, Mezhoud Samy, Melhem Abdul Qader

Civil and Environmental Engineering Reports

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2022

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Vol. 32, no. 3

166--181

EN

This paper deals with flexural investigation of a type of steel-concrete composite beam structure able to provide an adequate bond between steel and concrete elements through the application of a simple steel reinforcement shear connector design, steel reinforcing bars bent into L-shapes. The cross sections involve inverted steel T-beam being embedded within reinforced concrete (RC) flange of the slab. The paper concentrates on elastic and elastic-plastic behaviour of steel inverted T-beam entrenched within a reinforced concrete flange at the top. In addition, shear connection was investigated in detail. Finally, some suggested designing equations and curves simulating the elastic, elastoplastic and full plastic experimental moments were developed. The plastic theoretical study results coincides with the experimental behaviour of the developed model.

4

Characterization of Stabilised Sewage Sludge for Reuse in Road Pavement

Medaoud Saber, Mokrani Larbi, Mezhoud Samy, Ziane Sami

Civil and Environmental Engineering Reports

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2022

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Vol. 32, no. 1

201--217

EN

In recent years, the disposal of sewage sludge has been a major concern worldwide because of their potential treat in relation with the contamination of ground water and food chain. Furthermore, their poor mechanical properties don’t allow a possible direct use in civil engineering applications. For these reasons, it was important to explore more opportunity to reuse this by-product of sewage treatment. In this frame, the solidification-stabilisation technique (S-S) which is based on hydraulic binders can improve the properties of sewage sludge so that it can be used in civil engineering application, especially in road pavements. In this context, this paper investigates the possibility of using the solidified sludge in road construction. To achieve this goal, an experimental protocol was conducted using a several combined binders: combination of Cement/Limestone filler and Cement/Lime, with different amounts in the target to fix the optimal mixtures amount. Several tests were conducted to characterise the mechanical and geotechnical properties of the solidified sludge. The results indicate that the solidified sludge using a combined mixture of cement and lime allows a possible use as base and sub-base layer.

5

Experimental Study on the Durability Characteristics of Several Vegetable Fiber Reinforced Concretes Exposed to Sodium Sulfate

Ziane Sami, Khelifa Mohammed-Rissel, Mezhoud Samy, Beroual Ahmed, Medaoud Saber

Civil and Environmental Engineering Reports

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2021

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Vol. 31, no. 1

1--28

EN

Recently, numerous plant fibers have been investigated as a means to reinforce concrete and replace synthetic fibers, thereby producing more eco-friendly concretes. The primary concern for these studies is the durability of the fibers in the external environment. For this purpose, the current paper presents a comparison study on the physical-mechanical behavior and durability against external sulfatic attack on Alfa and Hemp fiber-reinforced concrete. To assess the effects of sulfatic attack, different types of concrete underwent two aging protocols: 1) a complete immersion in 12.5 % Sodium Sulfate (Na2SO4) solution and, 2) an accelerated aging protocol which consisted of immersion/drying in the same sulfate solution at a temperature of 60°C. The results show that the optimal amount of plant fiber is variable, depending on several parameters such as the chemical composition, mechanical characteristics, and morphology of the fiber. In addition, the results show that the use of Alfa and hemp fibers could facilitate the production of green and durable structural concretes.

6

Impact of elevated temperature on the properties of concretes reinforced with Alfa fiber

Mihoub Imane, Khelifa Mohammed-Rissel, Mezhoud Samy

Civil and Environmental Engineering Reports

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2020

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Vol. 30, no. 3

161--185

EN

Alfa fiber reinforced concretes are not used to their full potential due to the limited information on their properties, especially in more severe environments. In this study, the effects of elevated temperature on the properties of concretes reinforced with Alfa fiber were analyzed. The influence of fiber length on reinforced concretes is mainly investigated. For this purpose, five types of structural concretes were formulated; two types of concrete reinforced with 1% Alfa fiber volume using two different fiber lengths of 20 mm and 30 mm (AC-20, and AC-30), and three control concretes, two polypropylene fiber reinforced concretes (PC) using the same fiber length (PC-20, PC-30), and one ordinary concrete (OC). The results showed that with the increase of temperature, the mechanical performance decreased and the porosity rose continually for all mixtures. However, the use of Alfa fiber with a length of 20 mm showed the optimal results in terms of compressive and tensile strength, even at temperatures of 600°C. This finding suggests that Alfa vegetable fiber can be used to produce more sustainable concretes with acceptable mechanical properties compared to the use of polypropylene fiber, even under severe conditions of elevated temperature

7

A study of the durability of concrete reinforced with hemp fibers exposed to external Sulfatic attack

Ziane Sami, Khelifa Mohammed-Rissel, Mezhoud Samy

Civil and Environmental Engineering Reports

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2020

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Vol. 30, no. 2

158--180

EN

The purpose of this paper is to study the durability of concrete reinforced with hemp fibers in the face of external Sulfatic attack. For this purpose, five types of concrete were formulated; three types of concrete reinforced with hemp fibers (HC-0.25, HC-0.5, and HC-1) at 0.25%, 0.5%, and 1 % of hemp fibers in volume, respectively. And two control concretes, being ordinary concrete (OC) and polypropylene fiber reinforced concrete (PC). To assess the sulfatic attacks, the described concrete types underwent two aging protocols: 1) a complete immersion in 12.5 % Sodium Sulfate (Na2SO4) solution, and 2) an accelerated aging protocol consisting of immersion/drying in the same sulfate solution at a temperature of 60°C. The results show that concrete reinforced with 0.25 % of hemp fibers is the optimal amount compared to control concretes in terms of physico-mechanical performance and durability under sulfate attack. This number of fibers could enable the production of green and durable structural concretes based on untreated hemp fibers.