Journal of Materials and Engineering Structures

181-192

Authors: Santosh Gurjar, Jignesh. A. Amin

The assessment of wind loads on structure is generally carried out using existing codes/standards. The specifications of these codes are based on wind tunnel experiment performed on an isolated building. However, the buildings seldom exist in isolated condition. Neighbouring building may either increase or decrease the wind loads on principal building, this effect is known as interference effect. In this paper interference effect between two buildings is studied through numerical simulation using ANSYS CFX. Total drag force and interference factors for the principal building is calculated in the presence of interfering building having height ratio of 0.5, 0.75,1, 1.25, and 1.5. The results show that the upstream interfering buildings cause certain shielding effect by decreasing the mean wind load on the downstream principal building. However an amplification effect is also observed for certain location of the interfering building on upstream side. For buildings of the same cross-section, the interference factor (IF) decreases with the increase of the height of interfering building, indicating increase in the shielding effects. However the shielding effect on principal building is found to be significant when the heights of interfering buildings range from 0.75 to 1.5 of the height of the principal building. The along-wind force of the downstream principal building reduced to zero when the upstream interference building of height ratio more than one was two to three times the building breadth away from the principal building.

211-224

Authors: Mohamed Rida Seba, Said Kebdani, Ahmed Sahli, Sara Sahli

This article has been retracted at the request of the Editors-in-Chief, according to the Publication Ethics Policy and Publication Malpractice Statement. Please see : http://revue.ummto.dz/index.php/JMES/about/editorialPolicies#custom-2 This note is published, 25 June 2020

235-244

Authors: Mostefa Lecheheb, Rachid Lassoued

In this article, we study the dynamic behavior of the rail under inclined loads. The rail is modeled as a curved beam under lateral loads. When a train enters a curve, two sources lead to these lateral forces that have rarely been studied by previous researchers: the forces of action of the train result from the forces of the drawbar (due to centrifugal forces) and forces that develop due to the dynamic interaction of the vehicle and the rail. The rail is modeled as an infinite beam according to the Euler-Bernoulli theory. The use of a curved elementary section, allows to establish the solicitations that act the beam, and to write the differential equation of the system. The use of the residue theorem allows determining the Green function associated with the differential equation governing the vibration behavior of the rail system of the free beam.

259-267

Authors: Karthikeyan Loganathan, Mena I Souliman

The surface temperature of pavements is a critical attribute during pavement design. Surface temperature must be measured at locations of interest based on time-consuming field tests. The key idea of this study is to develop a temperature profile model to predict the surface temperature of flexible and rigid pavements based on weather parameters. Determination of surface temperature with traditional techniques and sensors are replaced by a newly developed method. The method includes the development of a regression model to predict the average annual surface temperature based on weather parameters such as ambient air temperature, relative humidity, wind speed, and precipitation. Detailed information about temperature and other parameters are extracted from the Federal Highway Administration's (FHWA) Long Term Pavement Performance (LTPP) online database. The study was conducted on 61 pavement sections in the state of Alabama for a 10-year period. The developed model would predict the average annual surface temperature based on the known weather parameters. The predicted surface temperature model for asphalt pavements was very reliable and can be utilized while designing a pavement. The study was also conducted on seven rigid pavement sections in Alabama to predict their surface temperature, in which a successful model was developed. The outcome of this study would help the transportation agencies by saving time and effort invested in expensive field tests to measure the surface temperature of pavements.

121-138

Authors: Houssam Khelalfa

A case study about the adoption of the dynamic compaction technique with high energy in a sandy hydraulic fill is presented. The feasibility of this technique to ensure the stability of the caisson workshop and to minimize the risk of liquefaction during manufacture. This Article is interested to establish diagnostic of dynamic compaction test, basing on the results of SPT tests and quality control as well as the details of work of compaction and the properties of filling materials. A theory of soil response to a high-energy impact during dynamic compaction is proposed.

155-167

Authors: Bouzid Haytham, Kassoul Amar

The ductility of reinforced concrete beams is very important, because it is the property that allows structures to dissipate energy under seismic loading, consequently, the brittle fractures of reinforced concrete structures can avoided. In the modern construction of reinforced concrete structures, the high-strength concrete (HSC) is widely used because of its benefits provided, such as the mechanical and durable properties. But the increasing of the concrete strength can negatively influence the ductility of reinforced beam sections, for this reason, the study of the local ductility of high-strength concrete beams is required. This paper present a numerical parametric study about the influence of different parameters on the curvature ductility of high strength concrete beams as the concrete strength, the yield strength of steel and the ratio of tension and compression reinforcements. In the end, a formula to predict the curvature ductility of HSC beams is proposed. This formula is compared with the Eurocode 2 numerical results and other numerical and experimental results.

79-86

Authors: O.A. Oyelaran, O. Balogun, A.O. Ambali, J.K. Abidoye

Skin processing produces large volumes of wastes, much of which are not utilized but disposed in the landfill. This study explored the possibility of producing briquettes from tannery waste that could be used for heating purposes for cottage factories and domestic cooking. Wastes studied are buffing dust, chrome shavings, fleshing, and hair. The briquette properties tested were moisture content, volatile matter, ash content, fixed carbon content, calorific value, compressive strength, density and durability. The moisture content of the raw materials ranged between 2.04 and 8.37% while the moisture content of the produced briquettes after 19 days of drying ranges between 1.17 and 4.13%. The volatile matter also decreases while the ash content increases after briquetting. The fixed carbon content ranges 73.79 and 93.23%. The heating values of the briquettes also showed a great increased after briquetting of between 19.82 and 21.86 MJ/kg. The compressive strength ranges between 0.17 and 0.21 kN/cm2, the durability ranges between 97.83 and 99.54%. The maximum densities of the briquettes also meet the required specifications of minimum value of 600 kg/m3. The briquettes produced also possess good qualities that make tannery solid waste a materials for production of briquettes for heating and in cottage industries

99-109

Authors: Hocine Hammoum, Akli Yahiaoui, Bachir Achour

In our previous study (Part 1); by using the graphic of Bergeron, we have drawn the relationships which allow calculating flows and pressures at the valve and the reservoir, considering that pressure losses are negligible. Now, we assume in this second contribution that these pressure losses are concentrated downstream of the pipe, just at the entry of the valve. The study will focus on water hammer-induced by a slow closing of the valve. A practical example will be presented at the end of this work in order to illustrate the exposed method.

11-23

Authors: Aziz Soufi, Ayoub Aitoubba, Khalil El-Hami, Mohamed Talea, Assia Bakali, Jean Grilhé

It is shown that very large stresses may be present in the thin films that comprise integrated circuits and magnetic disks and that these stresses can cause deformation and fracture of the material. For a crystalline film on a non-deformable substrate, a key problem involves the movement of dislocations in the thin film. An analysis of this problem provides insight into both the formation of misfit dislocations in epitaxial thin films and the high strengths of thin metal films on substrates. We develop in this paper, theoretical calculations for dislocation nucleation phenomena in nanomaterials obtained by hetero-epitaxial growth of thin films on substrates having lattice mismatch defects. Atomic force microscopy observations showed the nucleation of dislocations from free lateral surfaces to relax the "misfit" strain, here we explain the principle of nucleating edge dislocations from these surfaces by the theoretical calculation, using the method of image stress and energy study. We begin, by treating the case of a single dislocation and then generalize the work at a pile-up of n interface dislocations.

37-50

Authors: J.S. Yadav, S.K. Tiwari

Discarded waste tires are becoming a serious threat to health, environment, and ecological systems worldwide if it is not disposed of properly. Every year 1000 million of waste tires are discarded. This number may grow up to 1200 million by the year 2030. On the other hand, construction of civil engineering structures such as buildings, dams, highways, etc. are at high risk of differential settlement, especially in the case of weak or soft clay, which is due to its low shear strength and high compressibility. The paper aims to assess geotechnical properties of uncemented/cemented clayey soil incorporated with waste crumb rubber. Compaction parameters, unconfined compressive strength, split tensile strength, toughness index, CBR values and swelling pressure of rubberized uncemented/cemented clayey soil (3%, and 6% cement and different percentage of crumb rubber) have been obtained. After rigorous extensive study, it has been concluded that unconfined compressive strength and split tensile strength of rubberized cemented clayey soil decreases with the increase of the percentage of crumb rubber whereas the axial, and diametral strain are found to be increased with the addition of crumb rubber up to 5% after that it starts to decrease. The CBR values, swelling pressure, and toughness index of uncemented/cemented clayey soil was significantly affected by incorporation of crumb rubber. SEM studies have also been incorporated in this investigation.