bluuebunny/crossref_metadata_2025 huggingface dataset:
Connection behaviour and the robustness of steel-framed structures in fire
Authors: Burgess Ian
Published: February 2018

The full-scale fire tests at Cardington in the 1990s, and the collapse of at least one of the WTC buildings in 2001, illustrated that connections are potentially the most vulnerable parts of a structure in fire. Fracture of connections causes structural discontinuities and reduces the robustness provided by alternative load paths. An understanding of connection performance is essential to the assessment of structural robustness, and so to structural design against progressive collapse. The forces and deformations to which connectionscan be subjected during a fire differ significantly from those assumed in general design. The internal forces i generally start with moment and shear at ambient temperature, then superposing compression in the initial stages of a fire, which finally changes to catenary tension at high temperatures. If a connection does not have sufficient resistance or ductility to accommodate simultaneous large rotations and normal forces, then connections may fracture, leading to extensive damage or progressive collapse of the structure. Practical assessment of the robustness of steel connections in fire will inevitably rely largely on numerical modelling, but this is unlikely to include general-purpose finite element modelling, because of the complexity of such models. The most promising alternative is the component method, a practical approach which can be included within global three-dimensional frame analysis. The connection is represented by an assembly of individual components with known mechanical properties. Component characterization must include high-deflection elevated-temperature behaviour, and represent it up to fracture.In reality a connection may either be able to regain its stability after the initial fracture of one (or a few) components, or the first failure may trigger a cascade of failures of other components, leading to complete detachment of the supported member. Numerical modelling must be capable of predicting the sequence of failures of components, rather than considering the first loss of stability as signifying building failure. It is necessary to use a dynamic analysis, so that loss of stability and re-stabilization can be tracked, includingthe movements of disengaging members and the loadsharing mechanisms which maintain integrity and stability within the remaining structure, until total collapse occurs.
Corrosion behaviour of reinforced concrete constructions in acid aggressive environments: case studies, laboratory tests and corrosion mechanisms
Authors: Pepenar Ioan
Published: February 2018

The paper presents the results of research on the corrosion behaviour of reinforced concrete elements which compose the bearing structure of some constructions subjected to the corrosive action of acid aggressive agents, after a long-term service in a strongly aggressive environment. To evaluate the damage state of reinforced concrete elements/constructions, both “in situ” investigation of constructions and laboratory tests on concrete samples extracted from some elements damaged by corrosion, using a specific investigation methodology were performed. The results of the research revealed the existence of a severe corrosion-induced damage of the structural elements, which affected the resistance, stability and durability of the constructions. Based on case studies on the service behaviour of reinforced concrete elements, there are pointed out the specific damages generated by the corrosive action of the acid aggressive agents, the causes of their occurrence and presents considerations on the mechanisms of the corrosion processes of concrete and steel reinforcement in acid aggressive environments. Finally, there were proposed intervention measures in order to assure normal service conditions of the reinforced concrete constructions located in such aggressive environments.
The benefic effect of Moroccan oil shale’s ash on blended cement (CMII)
Authors: Houda Hamsi Nour El , Nabih Khadija , Barbach Redwan
Published: February 2018

Recycling of Tarfaya’s oil shales (OSA) was conducted for two essential reasons: First, to follow the change of their mineralogical composition with the heat treatment and second to investigate the possibility of their use in building materials. The mineral compositions and the mineralogical transformations of the oil shale during their thermal treatment were followed respectively by X-ray fluorescence (XRF), by X-ray diffraction analysis (XRD) and Fourier transform infrared (FTIR). The XRF showed that the mineral composition of the ash burned at 850°C is similar to that of Portland clinker and the DRX showed the presence of quartz, mayenite, gehlenite, anydrite, hematite and lime as well as the existence of some characteristics phases of the clinker as C2S, C3A and C4AF. The Infrared spectrum showed the various functional groups that exist in OSA. The substitution of cement CMII by OSA increased the content of free lime and Blaine specific surface. The ash influenced beneficially the mechanical strength of the blended cement. The best results were obtained at all times of curing (2, 7, 28 and 91 Days) for the substitution of CMII by 7 and 10 % of OSA.
The application of experimental design models in order to optimize the synthesis of geopolymers
Authors: Kioupis Dimitris , Skaropoulou Aggeliki , Tsivilis Sotiris , Kakali Glikeria
Published: February 2018

The aim of this work is to propose the methodology and the mathematical tools for the design and development of geopolymeric materials from industrial wastes and by-products. The applied methodology follows the Taguchi fractional experimental design allowing the investigation of the combining effect of selected parameters in the response of the experimental system by conducting the minimum number of experiments. Two cases of geopolymer synthesis optimization based on the mechanical strength and the apparent density of the products, to which the Taguchi methodology has been successfully applied, are presented in the paper.
Influence of recycled polystyrene beads on cement paste properties
Authors: Maaroufi Maroua , Younsi Akli , Belarbi Rafik , Nouviaire Armelle
Published: February 2018

In order to keep up with the requirements of sustainable development, there is a growing interest towards reducing the energy consumption in the construction and rehabilitation of buildings and the promotion of recycling waste in building materials. The use of recycled polystyrene beads in cement-based materials composition constitutes a solution to improve the insulation in buildings. This allows also limiting landfill by reusing the polystyrene waste. The aim of this study is to compare some properties and performances of a cement paste containing polystyrene beads to a reference paste designed with only the same cement. An experimental campaign was conducted and the obtained results showed that adding recycled polystyrene beads to a cement paste improves its hygro-thermal properties. Further studies are however necessary to better understand the real role of the polystyrene beads in the heat and mass transfers.
Thermal characteristics study of light aggregate concrete of the middle Atlas pozzolana
Authors: Bouyahyaoui A. , Cherkaoui M. , Abidi My L. , Cherradi T.
Published: February 2018

We present in this work an experimental study of the thermomechanical characterization of pozzolan (volcanic rock widespread in the region of Azrou in the Middle Atlas in Morocco). The objective of this work is to evaluate the effect of the pozzolan on the thermal conductivity of pozzolanic concrete by using different concrete formulations and this, by substituting various percentages of gravel and usual sands with gravel and sand of the pozzolan. The thermal properties of the samples consist to determine the thermal conductivity and the heat capacity. The results obtained show that the pozzolan is a local material with a high thermal resistance and can be used as a good insulated material in heat transfer and energy efficiency in the building.
Study of structural short order and surface changes of SiO2 compounds
Authors: Oufakir A. , Khouchaf L. , Elaatmani M. , Zegzouti A. , Louarn G. , Ben Fraj A.
Published: February 2018

In this work dependence between structure, surface and reactivity of SiO2 is investigated. Different samples are prepared with and without the presence of calcium cations and are characterized by different techniques. The FTIR frequency shifting of the bridging oxygen stretching vibration Si–O–Si and the binding energy shiftingof the Si2p and O1s photoelectron peaks have been observed and discussed. Results show the effect of presence of calcium on the structural change, surface and reactivity of SiO2 aggregate. After reaction, a structural and SiO2 surface changes occur, as the FTIR spectra illustrate depending on the presence of the calcium cations.
Inhibitive effect of N,N'-Dimethylaminoethanol on carbon steel corrosion in neutral sodium chloride solution, at different temperatures
Authors: Hassoune Mohammed , Bezzar Abdelillah , Sail Latéfa , Ghomari Fouad
Published: February 2018

The inhibition of carbon steel corrosion in neutral sodium chloride solution by N,N'- Dimethylaminoethanol (DMEA), at different temperatures, was investigated using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results obtained confirm that DMEA is a good organic corrosion inhibitor for carbon steel in 0.5M of NaCl (concentration encountered in the Mediterranean seawater), over the whole range of temperatures studied. The inhibition efficiency (IE%) increases with increasing DMEA concentration; it reaches highest value for a concentration around 0.125 mol.L-1. Potentiodynamic polarization data show that, the compound studied in this research predominantly act as anodic-type inhibitor. The EIS study reveals that the addition of DMEA decreases the corrosion rate of carbon steel in neutral sodium chloride solution, due to the fact that the inhibitor molecules are strongly adsorbed on the active sites following Langmuir isotherm, thus leading to the formation of a stable protective film on the steel surface which is able to keep the metal/solution interface in a passive state. Furthermore, the values of the activation parameters, i.e. ΔHa and Ea obtained in this study indicate that the adsorption process of DMEA is endothermic and could be mainly attributed to chemisorption, respectively.
Rheological study of self-compacting mortars based on ternary cements
Authors: Elhadja Dada , Salah Eddine Belaidi Akram , Hamza Soualhi , El-Hadj Kadri
Published: February 2018

Self-compacting concrete (SCC) is able to provide the ability to be easily implemented without vibration and to achieve spectacular structures, by its high fluidity and its rheological stability. By against its formulation requires a large volume of cement, which is necessary to allow its flow. The current environmental considerations lead to reduce the production of clinker however, it is essential to use cementitious additions to replace cement, because of their high availability and their moderate price. Furthermore, their use contributes in a simple and economical way to solve the problems related to the environment. The objective of our work is to study the effects of the incorporation of mineral additions such as: blast furnace slag of El-Hadjar (BFS), and marble powder (MP) on the rheological parameters of selfcompacting mortars developed in different combinations in ternary system with a substitution rate ranging from 20% to 60%. According to this study, it been found that the substitution of cement by blast furnace slag and marble powder has negatively affected the rheological behavior of the mixtures. In addition, a considerable decrease in the rheological parameters has been achieved with a substitution rate of 20% of slag and 30% of marble powder. As well as an improvement of workability has been proven to self-compacting mortars and this is due to the increase of ternary cement replacement rate by marble powder from 20% to 30%.
Blended cement hydration assessment by thermogravimetric analysis and isothermal calorimetry
Authors: Meziani Meriem , Chelouah Nasser , Amiri Ouali , Leklou Nordine
Published: February 2018

In the present study, the hydration of Portland cement pastes containing 5%, 10%, 15% and 20% tuff, limestone filler and granodiorite was investigated by thermogravimetric analysis coupled with differential scanning calorimetry and microcalorimetry isotherm. The monitoring of the hydration kinetics by thermogravimetric analysis made it possible to quantify the quantity of water combined with the cement (nonevaporable water) and the degree of hydration. By coupling this technique to the differential scanning calorimetry, it was also possible to measure the energy absorbed or released by the material during its decomposition. The results showed that the non-evaporable water content and the degree of hydration of the mixtures containing various mineral admixtures were relatively lower with respect to the reference mixture when as the content of mineral admixture increased. The effect of the evolution of the hydration process on the mechanical properties of mortars was also monitored. The relative variation of the compressive strength to that of the flexural strength was evaluated at 7, 28 and 90 days. Results showed that all the mixtures have a greater contribution in flexion than in compression.
Olive pomace based lightweight concrete, an experimental approach and contribution
Authors: Lynda Amel Chaabane , Rafik Benferrah
Published: February 2018

Due to conventional aggregates resources depletion, material recycling has become an economic and ecologic alternative. In this paper, locally available natural residues such as olive pomace were investigated, when partially incorporated in the concrete formulation, since the mechanical characteristics of lightweight aggregate concrete strongly depend on its properties and proportions. Lightweight aggregates are more deformable than the cement matrix because of their high porosity, and their influence on the concrete strength remains complex. The purpose of this paper is to investigate the aggregates properties on lightweight concrete mechanical behaviour through an experimental approach. In addition, the different substitution sequences and the W/C ratio on lightweight concrete behaviour were evaluated, in order to determine the W/C ratio influence on the improvement of the lightweight concrete mechanical properties while knowing that the mixing water quantity gives the cement paste manoeuvrability and mechanical strength effects. The last part of this paper, therefore, was to provide statistical survey for estimating strength and weight reduction through the different natural aggregate substitutions to improve the lightweight concrete properties. The results achieved in a significant olive-pomace lower adhesion with the matrix after the cement setting, making the lightweight concrete mechanical strength weak. However, this work can open several perspectives: Results modeling and correlation with an experimental approach, the evolution and determination of lightweight concrete characteristics when exposed to high temperatures and thermohydric properties.
Characterization and formulation of a new eco-friendly hydraulic binder based on combination of inorganic and organic admixtures
Authors: Khudhair M.H.R. , El Youbi M. S. , Essamri A. , Elharfi A.
Published: February 2018

This work aims to valorize a mineral and natural resources such as the Limestone Fillers (F-Lime) and the Natural Pozzolan (PN) by incorporating them into the formulation matrix of cement or concrete. In order to minimize the CO2 emissions into the atmosphere, to reduce the energy and raw materials consumption and as well as, to improve the physical and mechanical properties in fresh cement paste and of mortar or concrete in the hardened state. In this present manuscript, we substituted the clinker by the combination between the F-Lime and NP at 40% by weight of cement with steps of 5% with the admixture of superplasticizers. The influences of the incorporation of these additions on physical and mechanical properties of mortar or concrete in the fresh cement paste and hardened state were evaluated. The obtained results by different formulations elaborated to show that the replacement a part of clinker by the mixing of F-Lime and PN has produced a new hydraulic binder eco-friendly and durable with improved physicochemical, physical and mechanical properties. These results show that we have succeeded to manufacture, characteristic and formulated of new ecofriendly hydraulic binder and sustainable with improved physical, chemical, and mechanical properties while minimizing greenhouse gas emissions on one hand and the reducing the energy raw materials consumption on the other hand.
Study of Local and Distortional Stability of Thin-Walled Structures
Authors: Imene Mahi , Naoual Djafour , Mustapha Djafour
Published: February 2018

Thin-walled structures have an increasingly large and growing field of application in the engineering sector, the goal behind using this type of structure is efficiency in terms of resistance and cost, however the stability of its components (the thin walls) remains the first aspect of the behavior, and a primordial factor in the design process. The hot rolled sections are known by a consequent post-buckling reserve, cold-formed steel sections which are thin-walled elements also benefit, in this case, it seems essential to take into account the favorable effects of this reserve in to the verification procedure of the resistance with respect to the three modes of failures of this type of structure. The design method that takes into account this reserve of resistance is inevitably the effective width method. The direct strength method has been developed to improve the speed and efficiency of the design of thin-walled profiles. The latter mainly uses the buckling loads (for Local, Distortional and Global mode) obtained from a numerical analysis and the resistance curves calibrated experimentally to predict the ultimate load of the profile. Among those, the behavior of a set of Cshaped profiles (highly industrialized) is studied, this type of section is assumed to be very prone to modes of local and distortional instability. The outcome of this investigation revealed very relevant conclusions both scientifically and practically.
Major projects in urban sites: Challenge of the Builders
Authors: Dhouib Ammar
Published: February 2018

Faced with the complexity of urban construction projects and difficulties in the field, engineers must, on the one hand, dimension with rigor and common sense the foundations with all the requirements of today of quality, conformity and respect of deadlines and budget and take into account, on the other hand, safety and environmental requirements and societal and sustainable development criteria, the purpose of this communication is to present concrete projects of foundations and excavation deep in geologically heterogeneous and highly urbanized sites, with monitoring and displacement measurements in order to compare predictions with reality and to promote the "observational method".
Two-Stage Concrete as a Sustainable Production
Authors: Abdelgader H. S. , El-Baden A S. , Abdurrahman H.A. , Abdul Awal A.S.M.
Published: February 2018

Two-stage concrete (TSC) is a sustainable concrete which is produced by forcing a flowable cement grout mixture through the voids of a skeletal mass made of compacted preplaced aggregates. From the technical and economic aspects, TSC is particularly useful for construction and repair of concrete structures especially foundations, underwater construction, nuclear reactors, concrete dams, heritage structures and in constructions with closely spaced reinforcement. TSC differs from ordinary concrete in that it contains a higher proportion of stone aggregate and the aggregate stays in point-to-point contact as placed. Thus, the mechanical characteristics of the TSC in failure conditions are distinctly different from ordinary concrete. This paper presents the results of experimental investigations conducted to evaluate the compressive, tensile strength and modulus of elasticity of TSC using grouts with different water-to-cement ratios and admixture contents. It was found that the modulus of elasticity and splitting tensile strength of TSC are equivalent or higher than that of conventional concrete at the same compressive strength. In this method of construction, the splitting tensile strength can be conservatively estimated using the American concrete institute (ACI) equation for conventional concrete.
Developing a combined Light Detecting And Ranging (LiDAR) and Building Information Modeling (BIM) approach for documentation and deformation assessment of Historical Buildings
Authors: Yaagoubi Reda , Miky Yehia
Published: February 2018

Cultural heritage plays a fundamental role in preserving the collective memory of a nation.
However, it is noted that many historical buildings suffer from serious deformation that may lead to deterioration or loss. In this paper, we propose an approach for documentation and deformation assessment of historical buildings based on the combination of Terrestrial Light Detecting And Ranging (LiDAR) technology and Building Information Models (BIM). In order to digitally archive the current state of a historical building, classical surveying techniques (Traversing, Levelling and GPS) are integrated with Terrestrial Laser scanner (TLS). A Leica Scan Station C10 is used to accomplish the 3D point cloud acquisition. In addition, Leica GNSS Viva GS15 receivers, a Leica Total Station TCR 1201+ and a Leica Runner 24 are used for classical surveying. The result is a 3D point cloud with high resolution, which is referenced according to the local geodetic reference system Ain el Abd UTM 37N. This point cloud is then used to create a 3D BIM that represents the ideal condition of the building. This BIM also contains some important architectural components of the historical building. To detect and assess the deformation of building’s parts that require an urgent intervention, a comparison between the 3D point cloud and the 3D BIM is performed. To achieve this goal, the main parts of the building in the BIM model (such as ceilings and walls) are compared with the corresponding segments of the 3D point cloud according to the normal vectors of each part. A case study that corresponds to a historical building in Jeddah Historical City named ’Robat Banajah’ is presented to illustrate the proposed approach. This building was built to serve pilgrims that want to perform the fifth pillar of Islam. Then, it was endowed (waqf) as a charity housing for widows and disabled. The results of assessing deformations of the case study show that some rooms are in a degraded condition requiring urgent restoration (distortions reach up to 22 cm), while other building parts are in a non-critical condition.
Analysis of buckling phenomenon of rectangular laminated plates with a hole under different boundary conditions
Authors: El Bouhmidi Ahmed , Rougui Mohamed
Published: February 2018

In this research, buckling behavior of perforated rectangular plate of symmetric and anti-symmetric laminated composite is investigated based on Finite element analysis. The presence of hole may cause redistribution of stresses in plates with reduction of stability. The aim of the current paper is to find critical buckling load by using the (FSDT) first-order shear deformation theory in concomitance with the variational energy method. The load depends on many factors like as diameter of circular hole, different boundary conditions, lay-up sequences, length/thickness ratio and angle of ply orientation. The result is shown in graphical forms for various boundary conditions.
Structural evaluation updating based on quality control and proof loads
Authors: Saad Abbadi Mohamed , Lamdouar Nouzha
Published: February 2018

In a context of limited available resources, the structural evaluation of bridges is important to avoid the high costs of replacement and repair. As a rational evaluation criterion, the reliability of structures based on probabilistic theories provides an accurate estimate of the current strength and the remaining life time. It also represents an effective approach for analysing structural reliability under uncertainties in parameter estimates during the service life of designed and existing structures, especially during the construction.Where new information concerning the actual bridge conditions is available, which is unknown in the design phase. The certificates of material properties, measurements of actual bridge geometry, collection load data, and results of proof load testing are the major resources of this information. The extra information unknown in the design phase could be used to reduce some uncertainties related to the bridge member resistance and load parameters entering the evaluation process.The aim of this study is twofold: (a) taking into account the uncertainties ofstrength parameters, by presenting some approaches for the efficient inclusion of quality control and proof loads in the structural reliability assessment process.The results of these approaches reveals the actual safety margins in the structure and permits to avoid either unnecessary reinforcement operations or unjustified reduced load limits.
Estimation of the strength of Nubian sandstone formation from point load test index and other simple parameters
Authors: Zein Abdul Karim M. , Sandal Mutasim A.
Published: February 2018

This study investigates the correlation of the uniaxial compressive strength (UCS) and the point load test (PLT) index Is(50), bulk density, water absorption and the RQD properties of the Sudanese Nubian sandstone formation. The UCS being is the rock property needed in engineering practice but its determination is tedious, time consuming and expensive. Alternatively, the UCS may be indirectly evaluated through establishing relationships with rock parameters which are easier, cheaper and more convenient to determine in the laboratory or in the field. An extensive laboratory testing was executed to determine the above rock properties for many NSF samples taken from Khartoum State and other areas. Statistical analysis was performed on the test data and a reliable linear regression equation has been developed with a UCS to PLT Is(50) conversion factor of 10.18 and may be applied to estimate the strength of the Sudanese sandstone formation. The developed correlation is in good agreement with few of the many methods published for similar rock types which indicates that large errors may result in from applying an inappropriate UCS prediction method. Thus, it is important to establish separate correlations or validate published correlations to check their suitability for a specific rock types and local geologies. Useful correlation relationships of reasonable accuracy were also established for rough estimation of the UCS from the bulk density, water absorption and the RQD properties of the Nubian sandstone formation.
Correlation between Rock mass rating, Q-system and Rock mass index based on field data
Authors: Soufi Amine , Bahi Lahcen , Ouadif Latifa , Kissai Jamal Eddine
Published: February 2018

Throughout the last decades, many authors have published empirical correlations between rock mass classification systems that have arisen from a series of measurements and observations with the special conditions of the work site; this means that the validity of these expressions is strongly dependent on the knowledge of the original data from which they were deduced. Consequently, none of these expressions are universal nowadays.

In recent years, the principal corps B3 “CPB3” of IMITER mine area has witnessed massive mining activities involving a large amount of underground excavation, the rock mass characteristics are undoubtedly the essential requirements for empirical design and numerical modeling. Therefore, the research carried out aims to provide a new specific inter-relation between the most widespread Quality Indexes, Bieniawski’s RMR Quality Index, Barton’s Q Quality Index and Palmström’s RMi Mass index utilizing the data gathered from the jointed volcano-sedimentary rock mass of the “CPB3”.

The “CPB3” mining level is located in Imiter silver mine, eastern Anti-Atlas, Morocco, at a depth of 500m. A total of 128 rock blocks were examined for the rock mass quality using the three characterization systems, the outcrop mapping was carried out on freshly parallel exposed faces in the horizontal south to north direction. After processing and plotting the in-situ measured data, several equations of the three indexes has been investigated using regression modeling to analyze the obtained results and find the most suitable equation with the highest correlation coefficients. These relationships were then compared with those reported in the literature.

The proposed regression models reveal strong correlations between RMR, Q and RMi indexes with high values of accuracy coefficients so that they can be used to estimate the “CPB3” underground rock mass quality for the range of RMR between 30% and 80%. The developed mathematical formulations of the geomechanicalindexes will certainly offer an effective tool to geologist and geotechnical professionals in the decision-making process, preliminary design phase, stability problems and suggestions of the required supporting system and techniques without the expense of more resources or time.
Determination of the yield function and its derivatives of the Barcelona Expansive model
Authors: El Brahmi Jamila , Lamdouar Nouzha , Zoukaghe Mimoun
Published: February 2018

The main purpose of this paper is to determine the yield function F of the Barcelona Expansive Model and its partial derivatives with respect to the stress vector σ, the suction s and the hardening parameter χ. These results are important by the fact that they are used to solve the elastoplastic problem of unsaturated expansive soils.
Performance-based seismic assessment of vulnerability of dam using time history analysis
Authors: Elmrabet Oumnia , Boubel Hasnae , Mehdi Echebba El , Rougui Mohamed , Mouhat Ouadia
Published: February 2018

The current performance-based seismic assessment procedure can be computationally intensive as it requires many time history analyses (THA) each requiring time intensive post-processing of results. Time history analysis is a part of structural analysis and is the calculation of the response of a structure to any earthquake. It is one of the main processes of structural design in regions where earthquakes are prevalent. The objective of this study is to evaluate the seismic performance of embankment dam located on the Oued RHISS in the Province of AL HOCEIMA using the THA method. To monitor structural behavior, the seismic vulnerability of structure is evaluated under real earthquake records with considering the soil-structure-fluide interaction. In this study, a simple assistant program is developed for implementing earthquake analyses of structure with ANSYS, ground acceleration–time history data are used for seismic analysis and dynamic numerical simulations were conducted to study and identify the total response of the soil-structure system.
Soil-fluid-structure interaction applied to the Oued Taht dam (taking into account the membrane effect).
Authors: Nasreddine Krenich , Berrrabah Amina Tahar , Youcef Houmadi , Mohamed Belharizi , Mohamed Mehdeli , Mohamed el Amine Mohammedi
Published: February 2018

The objective of this work is to analyze the dynamic behavior (modal behavior) of the "Oued Taht" arch dam located at MASCARA, taking into consideration the effect of soil-fluid-structure interaction. The finite element code "Ansys" was chosen for the dynamic modeling of the dam that is the subject of this study. Three hypotheses were used for soil-structure interaction modeling; model with embedded base which corresponds to the case where the phenomenon of interactions soil-structure is neglected, model with ground of foundation without mass which consists in taking into account the kinematic component of interaction soil structure and neglecting the inertial component and the model with foundation soil with mass where the two components of soil-structure interaction are taken into account. For the fluid, the model of added masses (equivalent to the westergaard approach) using the SURF element available in the Ansys code library was used. A comparison between the different models of the "Oued Taht" dam was made; it has been found that the taking into account of the soil-fluid-structure interaction phenomenon modifies the period of the system and that the modeling of the dam with and without fluid gives a very important difference of the periods. The results obtained were compared with those of the "Brezina" dam, which is a gravity dam located in BAYADH. The work has shown that the periods of the "Oued Taht" dam with soil-fluid-structure interaction modeling are very out of phase with the periods without fluid modeling (taking into account only the soilstructure interaction phenomenon). which is not the case for the Brezina dam where the periods for the two models are getting closer. The periods between the two models mentioned before are close to the dam of Brézina because the latter is a dam which participates much more by its own weight than by its vault (thickness of the vault varies between 36.3 m at the base and 5m in crest) which is the opposite for the dam "Oued Taht" which participates by its vault (constant thickness of 7 m) thus the membrane effect is present, which is translated by the shift of the periods between the empty case and the filled case.
Evaluation of landfill site choice using AHP and GIS case study: Oum Azza, morocco
Authors: Ait Errouhi A. , Bahi L. , Ouadif L. , Akhssas A. , Bouroumine Y. , Bahi A.
Published: February 2018

The amount of household waste produced by the mainly urban population in Morocco continues to increase year after year. Morocco is thus confronted with the problems of storage and disposal of this waste, which are composed largely of organic matter, bio-waste. In the recent past, these wastes have been buried in wild dumps or in old quarries located in areas close to urban centers without any treatment or control. This can constitute significant risks both for public health and the environment and for the future of the socio-economic activities of the country. For which evaluating municipal landfills is vital due to the importance of health and environmental issues and the possibility of contravening environmental and engineering criteria and principles. The present research is conducted using new techniques of approach among others, the analytical hierarchy process AHP, which will allow us to weight and combine all criteria and to classify their respective weights, as well as the use of GIS which will contribute to the evaluation of these criteria in order to determine whether the choice of the current site according to the results of our study meets the requirements of a controlled landfill respecting the environment.
Environmental and energy assessment of the use of Andesite in cement
Authors: Hamidi Moussa , Kacimi Larbi , Clastres Pierre
Published: February 2018

The present study is a contribution to the research of new sources of supply of additions and raw materials in order to valorize local materials in the manufacture of cement. It consists in checking the environmental validity of the industrial use of andesite by evaluating the energy consumption of manufacturing andesitic cement. This evaluation was made on CEMI 52.5R type cement mortars whose basic constituent is clinker, with substitution rates of raw and calcined andesitic rock at 800 °C varying from 0-40%. and this through mechanical performance tests at several deadlines (2 days, 7 days, 28 days and 90 days). The results show that the analysis of the influence on the environment of this addition, in its raw state or calcined at 800 ° C, made it possible to say that globally the impact of andesite on the matrices seems positive to long term. The replacement of the cement by andesite systematically induces a reduction in the energy required to produce one ton of binder, due to the lower energy demand for grinding than that required for the thermal treatment of the clinker. Overall, the energy cost of andesite cement (in kWh per MPa compressive strength) is lower than that of ordinary cement for low rates of clinker replacement and obtaining cements with moderate strengths.
Analysis of the restoration of mosque Ali Betchine of Algiers
Authors: Nassereddine Attari , Zineb Mechouari , Souad Laoues
Published: February 2018

Ali Betchine is one of the oldest mosques in the city of Algiers of the Ottoman period. Classified as a national monument in 1947. In 1986, UNESCO gave Ali Betchine its universal cultural dimension. This classification of the mosque has resulted in the building currently being protected from any major architectural shuffle in order to protect and preserve it. The Ali Betchine mosque underwent several transformations during the French colonization, it was converted into a church under the name “Notre Dame des Victoires”. After the independence of the country, this church was converted into a mosque. The evolution of heritage protection in Algeria can be monitored after a period of follow-up by the country's first regulations on heritage protection. It is noticed that an awareness of the architectural heritage of the country was beginning to emerge. The Ali Betchine mosque underwent restoration work which ended in September 2010 after more than twelve years of closure to the faithful. The paper traces the different stages of its restoration.
Crack identification based on the nonlinear response of plates with variably oriented surface crack.
Authors: Chouiyakh H. , Azrar L. , Alnefaie K. , Akourri O.
Published: February 2018

In order to secure structural and operational safety of structures, it is important to implement a structural health monitoring (SHM) strategy to issue early warnings on damage or deterioration prior to costly repair or even catastrophic collapse. Developing a SHM strategy for structures enables evaluating structural integrity, durability and reliability of the monitored structure. Hence, the main objective of this work is to develop a damage detection procedure based on a plate’s dynamic response and the Hilbert transform. Rectangular plates are considered and assumed to contain a surface crack which is centrally located, with a depth of h0, a length of 2C and inclined with an angle β. Von Karman plate theory is adopted herein, and the crack is modeled through the line spring model given by fracture mechanics. The plate is assumed to behave nonlinearly due to large deformation. The differential quadrature method is used to investigate the linear and nonlinear dynamic behaviors of cracked plates. The influence of crack’s parameters on modal properties is discussed. The eigenfrequencies of cracked plates with respect to crack half length C and orientation β are performed. For crack characterization, Hilbert transform is applied to the obtained linear and nonlinear time responses. It is shown throughout this paper that identified backbones describe changes in crack orientation.
Study of the interaction of the rupture zones of contiguous anchor plates in analogical medium
Authors: Abbad H. , Elmeiche N. , Mechab I. , Zemri C.
Published: February 2018

Knowing what occurs above anchor plates is certainly instructive. In this general vision of the interaction soil-anchor plates that our work was directed. An experimental study which required the design and implantation of a model containing plastic granules powder to similate a natural environment, is presented. The latter is subjected to the removal of anchor paltes. For each test, digital photographs are taken to materialize different deformed configurations during the pullout process. These photos processed in couples by the 7D software (image correlation) giving the evolution of the displacement field and plane strain analogical environment. Particular attention is paid to the discussion of the interference of rupture zones of contiguous anchors by reducing the distance between plates.
Simple Evaluation of the Influence of an Inert Additive on the Swelling Characteristics of Clay Soil
Authors: Louafi Bahia , Bahar Ramdane
Published: February 2018

In this study, an experimental investigation carried out to assess the performance of addition of an inert material on stabilization of an expansive soil in order to solve the lifting structures caused by this phenomenon. The results showed that an addition of glass is capable of reducing the actions of swelling. From the global analysis of the porosity using an ultrasonic device, we measure the propagation velocities of ultrasonic pulse through the tested clay samples. This reveals a change occurring in the porosity of the clay when glass is added to it. As a result some interesting conclusions concerning the expansive soil-material amendment are drawn.
Contribution of geophysics for the characterization of ore deposits, case of the Bouarfa mine, Morocco.
Authors: Anas Bahi , Ahmed Akhssas , Latifa Ouadif , Errouhi Ahmed Ait , Ouatiki Kawtar
Published: February 2018

Geophysical methods are one of the best ways to determine the potential of a mining area. Indeed, for the prospection of metalliferous deposits, the magnetic method remains essential as it makes it possible to characterize the extent and the depth of the anomalous bodies present in the prospected zone, mainly due to their reaction with the values of the total magnetic field. Thus, for the manganese mining zone of Bouarfa and more exactly Hammraouet, the genesis of the deposit is such that the manganese is generally associated with ferruginous minerals and clearly affect the total magnetic field. That said, the raw results obtained must imperatively be subjected to corrections to only keep the effect of the anomalous bodies on the magnetic field. Hence, we must proceed with the correction of the daytime effect then we eliminate the regional effects to get the map of the residual anomaly and finally we perform a reduction to the pole that will allow us to have well individualized and unipolar anomalies and thus allowing us to locate precisely the potentially mineralized axes. The synthesis of the various maps obtained by spatial interpolation of the data recorded in situ and corrected allows us to locate areas of mining interest and to determine the different tectonic phenomena that took place in our study area. In time, these maps will serve us to guide the subsequent mechanical surveys to confirm the results obtained by geophysical methods.
Vibration analysis of carbon nanotubes-based zeptogram masses sensors and taking into account their rotatory inertia
Authors: Azrar A. , Azrar L. , Aljinaidi A. A.
Published: February 2018

In this research work, the transverse vibration behaviour of single-walled carbon nanotubes (SCNT) based mass sensors is studied using the Timoshenko beam and nonlocal elasticity theories. The nonlocal constitutive equations are used in the formulations and the CNT with different lengths, attached mass (viruses and bacteria) and the general boundary conditions are considered. The dimensionless frequencies and associated modes are obtained for one and two attached masses and different boundary conditions. The effects of transverse shear deformation and rotatory inertia, nonlocal parameter, length of the carbon nanotubes, and attached mass and its location are investigated in detail for each considered problem. The relationship between the frequencies and mode shapes of the sensor and the attached zeptogramme masses are obtained. The sensing devices for biological objects including viruses and bacteria can be elaborated based on the developed sensitivity and frequency shift methodological approach.
Adsorption of cationic dye onto fly ash-based geopolymer: Batch and fixed bed column studies
Authors: El Alouani Marouane , Alehyen Saliha , El Achouri Mohammed , Taibi M’hamed
Published: February 2018

Cationic dye adsorption from aqueous solution onto synthesized geopolymer was investigated by batch and fixed bed column experiments. The geopolymer material was elaborated by alkali solution and fly ash supplied by Jorf Lasfar power plant of Morocco. Physical and chemical characteristics of samples were determined by FX, DRX, SEM, 29Si MAS NMR and Zeta potential methods. The Brunauer, Emmett and Teller (BET) technique is used to determine the surface area. The Barrett-Joyner-Halenda (BJH) method was performed to obtain pore size distribution curves and average pore diameter. Kinetics data were analyzed using pseudo-first-order, pseudo-second-order and intraparticle diffusion models. To predict the breakthrough curves and determine the main fixed bed column parameters, three kinetic models; Tomas, Bohart–Adams and Yoon-Nelson models are applied to fitting the experimental data. The kinetic study showed that the pseudo-second-order can be used to describe the methylene blue (MB) adsorption process on the geopolymer matrix. The kinetic models of the adsorption in dynamic column are suitable to describe the continuous adsorption process of dyestuff by the geopolymer. The results of this study indicated that geopolymer derived from fly ash can be used as a low cost effective adsorbent for cationic dye removal from industrial aqueous effluent.
Solar Desalination by Humidification-Dehumidification of Air
Authors: Moumouh J. , Tahiri M. , Balli L.
Published: February 2018

The importance of supplying potable water can hardly be overstressed. In many arid zones, coastal or inlands, seawater or brackish water desalination may be the only solution to the shortage of fresh water. The process based on humidification-dehumidification of air (HDH) principle mimic the natural water cycle. HDH technique has been subjected to many studies in recent years due to the low temperature, renewable energy use, simplicity, low cost installation and operation. An experimental test set-up has been fabricated and assembled. The prototype equipped with appropriate measuring and controlling devices. Detailed experiments have been carried out at various operating conditions. The heat and mass transfer coefficients have been obtained experimentally. The results of the investigation have shown that the system productivity increases with the increase in the mass flow rate of water through the unit. Water temperature at condenser exit increases linearly with water temperature at humidifier inlet and it decreases as water flow rate increases. HDH desalination systems realised on also work at atmospheric pressure; hence they do not need mechanical energy except for circulation pumps and fans. These kinds of systems are suitable for developing countries. The system is modular, it is possible to increase productivity with additional solar collectors and additional HDH cycles.
Copper(II)-Promoted Mono-Selective ortho C–H Chlorination of Arenes by Using Trimethyl(trichloromethyl)silane
Authors: Xu Changming , Zhu Zhaobin , Wang Yongchang , Zhao Li
Published: February 2018

The first example of a Cu-promoted ortho-chlorination of aryl C–H bonds by using TMSCCl3 as chlorinating agent is reported. This reaction features a high selectivity toward monochlorination over dichlorination, compatibility with a variety of functional groups, and gram-scale synthesis.