Glueberry fruit powder has been used to enhance the viscosity of flour for the production of glutten-free biscuits with limited use for self-compacting concrete. It is for this reason that this study investigated the potential use of glueberry fruit powder as a viscosity modifying admixture for the production of self-compacting concrete. Both fresh and hardened properties were measured, at varying percentage addition levels of 0, 5, 10, 15 and 20% by weight of cement, and indicated as A0 (control), B5, B10, B15 and B20 (experimental) respectively. A total of 120 cubes and 60 cylinders, were prepared and tested for the 7, 14, 28 and 90 days, curing phases. At a constant water/cement ratio and Conplast SP 430 addition, varied glueberry powder dosage caused an increase in setting times, plastic viscosity, flowability, passing-ability and segregation resistance, with further addition. Strength properties increased to maximum values at the 15% addition compared to the control and dropped with further addition in all curing durations. Water absorption decreased significantly to the 15% addition and marginally at the 20% addition compared to the control. The study recommended 15% glueberry fruit powder addition by weight of cement for the production of self-compacting concrete in hotter environments.

Crude oil contamination poses significant environmental issues, particularly in regions where oil spills affect soil and groundwater. Utilising damaged materials in construction offers a cost-effective rehabilitation strategy that repurposes waste and reduces pollution. This study examines the effects of curing methods and heavy crude oil contamination on the mechanical properties of cement mortar. Mortar samples with different amounts of heavy crude oil (0%, 2%, and 10%) were cured using air, water, and sealed plastic. Water curing attained the highest compressive strength across different pollution levels by maintaining moisture for complete hydration. In contrast, air curing resulted in the lowest strength, especially for uncontaminated and 2% oil samples, due to rapid drying that limited hydration and increased porosity. Curing techniques did not affect the strength of samples with 10% heavy crude oil, perhaps due to oil saturation impeding hydration. Increased oil contamination, particularly with heavy crude, significantly enhanced porosity and reduced compressive strength. The high viscosity and complex molecular structure of heavy crude oil form a dense coating around cement particles, hindering hydration and undermining the integrity of the cement matrix. The findings suggest that selecting an appropriate curing procedure for low-level crude oil may facilitate repurposing materials contaminated with heavy crude oil as sustainable, cost-effective alternatives for specific civil engineering applications, offering a viable option for oil-contaminated sand.

Application of high volume fly ash concrete is still not advocated by construction fraternity due to lack of standardisation. In India, fly ash as a pozzolanic material can be used in manufacturing of Portland Pozzolana cement and composite cement with a maximum limit of 35%. Present study had been carried out at various percentages of fly ash and a detailed mechanical and durability study was conducted. In this paper, concrete mixes were designed at two water binder ratio with 30%, 35%, 40% and 50% fly ash content. Mechanical behaviour of concrete was studied through tests like compressive strength (at age of 1, 3, 7, 28, 56 and 90 days) and flexure strength (at an age of 7, 28 and 90 days). Durability aspect of high volume fly ash concrete mixes were determined through various test like RCPT, non-steady state chloride migration, bulk conductivity, accelerated carbonation etc. and comparison is made with control mixes (i.e. concrete made with OPC). Alkali silica reactivity (ASR) study was also carried out at 30%, 35%, 40% and 50% fly ash content using reactive aggregates. It was quite evident from test results that strength characteristics of high volume flyash concrete mix made with 50% flyash content was remarkably lower than that of all other concrete mixtures. High volume flyash concrete mix designed at 40% flyash content had shown exemplarily performance in comparison to other high volume flyash concrete mixes as well as control mixes. Flyash content was found to most significant parameter influencing rate of carbonation.

The main interest of this paperwork is to examinate the dynamic behavior (free vibrational response) of carbon nanotubes (CNT) composite beams standing on an elastic foundation of Winkler-Pasternak’s. The affected beam consists of a polymer matrix reinforced with single-wall carbon nanotubes (SWCNT’s), in which, a large number of CNT’s reinforcement of infinite length are distributed in a linear elastic polymer matrix. In this study the CNT’s are considered either aligned or randomly oriented on the matrix.
 A refined high-order beam theory (RBT) is adopted in the present analysis using a new shape function. The refined beam theory which is summarized by differentiating the displacement along the beam transverse section into shear and bending components, initially the material properties of the composite beam (CNTRC) are estimated using the Mori-Tanaka’s method. The beam is considered simply supported on the edge-lines. NAVIER’s solutions are proposed to solve the boundary conditions problems. Since there are no results to compare with in the literature; the results in this study are compared with a free vibrational analysis of an isotropic beam. Several aspects such as the length/thickness ratio, volume fraction of nanotubes, and vibrational modes are carried out in the parametric study.

The purpose of this work consists of valorizing a local sand dune which is found in abundance in the region of Djelfa (Algeria); for use in pavement foundations. For this investigation a method of formulation has been proposed, which based on the stabilization of this material using a mixture of two hydraulic binders. Various mixtures were subjected to classification tests, tests grain size distributions, tests of compaction with modified Proctor, shear strength, tests of bearing pressure (CBR unsoaked and soaked), compressive strength and tensile strength. The results obtained have shown that some mixtures are of high mechanical characteristics and could be then used in road foundations.

The main purpose of this paper is to examine the development and current status of prefabrication techniques and their application in building construction and why its use is still limited in the housing sector in India and why prefabrication is not being used so far to provide affordable housing to all. Prefabrication is the practice of assembling components of a structure in factories, and then transporting the complete assemblies or sub-assemblies to the construction site where the structure is to be located. The important aspect is how much of a potential difference it can establish so that appropriate development can be implemented. This paper reviews the current prefabrication system scenario for housing in India. The paper begins with a brief introduction about different types of prefabrication system. Subsequent topics address the need of prefabrication and ethical dilemma of technology transfer for prefabricated building system in India. In this paper, a qualitative descriptive evaluation research method has been used. The research methodology comprises of case studies, visual observation and data collection. Finally, two case studies around the world have been presented to validate and illustrate the various modern trends and application of design and construction methods of prefabricated building system in housing.

The pathology that appears in reinforced concrete structures, old and new, is inevitable and involves all stakeholders at all levels of responsibility, from the technician to the decision maker at the highest level. It also concerns engineers from design offices and experts from offices responsible for diagnosing existing structures, as well as engineers from repair companies. Like all countries in the world, the study of the pathology and safety of civil engineering buildings is one of the big problems encountered in the field of construction in Algeria. The foundations are among of the structural elements of the buildings most affected by this damage, these constitute the link between the structure and the soil, they allow the transmission of loads from the structure to the soil. If these structural elements are damaged, they affect the general stability of the building. Depending on the severity of the damage, it can cause the building collapse. The main objective of this paper is to study a pathological case of foundation failure of a residential building: from diagnosis to reparation. This repair was carried out according to an intervention plan comprising stages spread over time, this allowed the strengthening of the infrastructure and gave the building an acceptable level of security.

The field of repair and rehabilitation of civil engineering works is evolving. Indeed, most of these structures, especially masonry structures, are over 50 years old and many of them require maintenance and repair work due to their deteriorated condition. To achieve this objective, a study was carried out concerning the different pathologies affecting the masonry bridges, but also the ways and means necessary for the evaluation and repair of the affected works. The results of this work have not only helped to carry out the diagnosis and verification of the structural state of the bridge over river Kentra Stora Skikda (North-East of Algeria), on the section of the 3AA National Road Skikda, but also for the proposal of repair solutions best adapted to the disorders observed.

The latest earthquakes history shows that resistant conception, safe and economical structures are a daily challenge for structural engineers. Among the newest vibration control devices figures the inerter which is a device which can develop a large fictive mass (it consists of a mass amplification effect) using rotational inertia. In this research work, the effectiveness of a traditional passive tuned mass damper (TMD) is compared with a tuned mass damper inerter (TMDI) which consists generally of tuned mass damper coupled with an Inerter. Both devices are used to control a base-isolated structure vibration submitted to several seismic records. In This study, a base-isolated structure of six stories (6 DOF) was equipped with (TMD) and (TMDI) and a time history analysis were performed under different earthquake records (El Centro, Kobe, Kocaeli). The mathematical model of the building is established in MATLAB Simulink. The simulation results illustrated he robustness, performance and effectiveness of the structure equipped with a (TMDI). The dynamical parameters of interest were base and top displacement as well as the base shear force and peak inerter force produced.

The current work investigates the effect of thickness stretching on the natural frequencies of laminate-faced sandwich plates using new layerwise finite element model. The proposed model assumes higher-order displacement field for the core and first-order displacement field for the face sheets. Thanks for enforcing the continuity of the interlaminar displacement, the number of variables is independent of the number of layers. The consistent mass matrix and the element stiffness matrix are derived using the Hamilton’s principle. The performance and reliability of the proposed formulation are demonstrated by comparing the author’s results with those obtained using the three-dimensional elasticity theory, analytical solutions and other advanced finite element models.