Accepted Papers to Appear in Future Issues

Workability, compressive strength and initial surface absorption of laterized concrete

Samuel Olufemi FOLAGBADE, Opeyemi Ayodeji OSADOLA

Abstract
This paper investigated the workability, compressive strength and initial surface absorption of plasticised laterized concrete at the water/cement ratios of 0.30, 0.50 and 0.70. Slump, compressive strength at 7, 14, 21 and 28 days and initial surface absorption after 10 minutes (ISA-10) at 28, 60 and 90 days were determined at the laterite contents of 0, 20, 40, 60, 80 and 100%. ISA-10 was also assessed at 28-day strengths of 20, 25 and 30 N/mm2. Results showed that superplasticiser dosage increased with increasing content of laterite and for economic dosage laterite content should be limited to 40%. At equal water/cement ratios, compressive strength reduced with increasing content of laterite and ISA-10 increased with increasing content of laterite. The results also showed a strong relationship between ISA-10 and compressive strength and that laterized concrete, when specified on the basis of strength, would have resistance to initial surface absorption comparable with that of the conventional concrete if laterite content is limited to 40%. Hence, for good workability, compressive strength and permeation resistance, laterite content of concrete should be limited to 40%.
Date accepted : 2019-03-10

Investigation on the glass fiber reinforced geopolymer concrete made of M-sand

Chithambar Ganesh A, Muthukannan M

Abstract
This research work investigates the effect of utilization of glass fibers in geopolymer concrete made of Manufactured sand (M-sand) over its fresh and hardened properties and understand the influence of fibers over reducing the brittleness of the matrix. Geopolymer concrete synthesized in this study is Fly ash- GGBS blend type with optimum molarity cured under heat condition. Fresh property of the fiber reinforced geopolymer concrete was accessed using compaction factor test. Mechanical properties such as compressive strength, split tensile strength, flexural strength, impact strength, ductility factor, first crack toughness, failure crack toughness and ultimate failure toughness were measured and their results are analyzed and discussed in this work. Later, SEM analysis was carried out over the optimum fiber reinforced geopolymer concrete samples to understand the bonding and the effectiveness of the fiber reinforced geopolymer concrete made of M-sand. Incorporation of glass fiber s proved to be more beneficial and yielded a hybrid concrete with increased strength properties. The performance of fiber s could be measured precisely in increasing the ductility and impact strength. Scanning Electron Microscopy (SEM) analysis showed better bonding between the fiber s and the matrix. This study unleashes an enormous scope for the practical implication of fiber reinforced geopolymer concrete as a building material.
Date accepted : 2019-04-25

Estimation of compressive strength of high-strength concrete by random forest and m5p model tree approaches

Balraj SINGH, Parveen SIHAG, Anjul TOMAR, Ankush SEHGAD

Abstract
High strength concrete (HSC) define as the concrete that meets a unique mixture of performance uniformity requirements that cannot be reached routinely using conventional constituents and regular mixing, placing, and curing events. The modeling of such type of concrete is very difficult. In this investigation, the performance of the random forest regression and M5P model tree were compared to estimate the 28th day compressive strength of the HSC. Total data set consists of 83 data out of which 70 % of the total dataset used to train the model and residual 30 % used to test the models. The accuracy of the models was depending upon the three performance evaluation parameters which are correlation coefficient (R), root mean square error (RMSE) and maximum absolute error (MAE). The results recommend that random forest regression is more accurate to predict the compressive strength as compare to M5P model tree. Sensitivity analysis indicates that water (W) and Silica fumes (SF) are the most valuable constituents of the HSC and compressive strength mainly depends on these constituents.
Date accepted : 2019-05-07

Effect of Chemically Modified Banana Fibers on the Mechanical Properties of Poly-Dimethyl-Siloxane-Based Composites
Yiporo Danyuo, Taiwo Zakariyyah, Nasiru Suleman, Kabiru Mustapha, Tahiru S. Azeko, Sefiu A. Bello, Miriam Abade-Abugre, John Yirijor, Victor Anyidoho, Fred McBangonluri

Abstract
The study presents the mechanical properties of polymer-based composites reinforced with chemically modified banana fibers, by alkalization in different concentrations of sodium hydroxide (NaOH). The fiber weight fraction has a great effect on the mechanical properties of the composites. Stiff composites were obtained at 6 wt% fiber fractions with Young’s modulus of 254.00 ±12.70 MPa. Moreover, the yield strength was 35.70 ±1.79 MPa at 6 wt% fiber fractions. However, the ultimate tensile strength (UTS) ) and toughness of the composites were obtained at 5 wt% fiber fractions. Statistical analyses were used to ascertain the significant different on the mechanical properties of the fibers and composites. The implication of the results is then discussed for potential applications of PDMS-based composites reinforced with chemically modified banana fibers.
Date accepted : 2019-05-19

Sorption mechanism of copper ions on synthetic and natural dentine hydroxyapatites
Farida Fernane, Saliha Boudia, Ahmad B.Albadarin, Farid Aiouache

Abstract
Removal of copper ions from aqueous solutions on synthetic and dentine waste hydroxyapatites (HAP) was investigated in batch sorption experiments. Kinetics of sorption followed a pseudo-first order model. Steady-state data show agreement with the Sips isotherm compared with Freundlich and Langmuir models. The higher surface area and carbonated nature of synthetic hydroxyapatite were not sufficient to reach higher sorption capacity than natural one. Ion-exchange and precipitation contributed on removal of Copper despite level ionization of hydroxyapatites. Proton and metal exchanges with copper ions contributed to process of sorption with prevalence of proton-exchange at low copper ion concentrations. High temperatures promoted the removal efficiency of Cu(II) onto the natural and synthesised hydroxyapatites. The thermodynamic parameters showed that sorption process was spontaneous, endothermic and associated entropy at the solid/solution interface increased at high temperatures.
Date accepted: 2019-06-03

Durability performance of Green Concrete Incorporating Various Wastes: A Review
Salmabanu Luhar, Ismail Luhar

Abstract
The present research manuscript stands for the review on the topic of durability attribute of concretes developed by means of green conception with incorporation of a variety of solid industrial waste slag from Ground Granulated Blast Furnace, silica fume, rice husk ash, pulverised fly ash, glass powder waste as well as materials that have undergone recycling in order to know its degree of sustainability. It is highly sought-after to transform these types of waste into a precious adding up materials in place of Ordinary Portland Cement (OPC) in building-up of Green concrete with affordable cost and more essential with a little carbon footprint. How far these Green concept concretes have succeeded in context to its durability characteristic is the principal focus of this review study. There prevails an enormous demand for cost-effective construction materials for offering enough residences and infrastructure networks to get rid of the burgeoning population on the planet earth. The centre of attention is to make researcher, engineer and infrastructure related peoples, as well as construction industry au courant of absorbing the, dissipate materials and their promotion as an acceptable, sustainable and cost-effective building materials. The apposite standards of durability and still excellent researches on the sustainability of this novel Green concept concrete will encourage for espousal of gargantuan construction and infrastructures projects globally. Looking to the above facts, it can be predicted that the said Green technology bestows the impression to have dazzling potential and its approval in construction industries which establishes it as the most promising future edifice material.
Date accepted : 2019-06-03

Fracture parameters formulation for single edge notched AS4 stitched warp-knit fabric composite plate
Mostefa Lallam, Said Mamouri, Abdelkader Djebli

Abstract
The three-dimensional problem of the fracture for the single edge notched tension plate (SENT) of orthotropic material is considered in this paper. The finite element solution is used to evaluate the singular and non-singular terms of the William series, i.e. Stress intensity factor (SIF) and T-stresses namely T11, T13 and T33. Based on the obtained numerical results, a fitting procedure is performed in order to propose analytical formulations giving the fracture parameters near the crack tip. The obtained results are in good agreement with the finite elements calculation and other literature results.
Date accepted : 2019-06-10

Deriving a specific response spectrum from the site of the Algiers Grand Mosque (Algeria)
Tounsia BOUDINA, Ahcene SERIDI

Abstract
The estimation of the soil seismic response at the surface can be made by several experimental methods, approximate and numerical. This study consists in using numerical simulation to determine the surface response in terms of maximum acceleration and response spectrum of soil profiles located at the site of the Grand Mosque of Algiers, taking into account the soil’s non-linearity behavior, with an equivalent linear behavior (hysteresis degradation of the shear modulus G). The responses calculated on the surface that they are amplified or de-amplified compared to the excitation at the base (earthquake of May 21, 2003 in Boumerdes) indicate the presence of the site effects and which allows the derivation of a spectrum calculation to the studied site.
Date accepted : 2019-06-10

Effect of a crack emanating from notch on a composite pipe subjected to buckling
Halima CHENINE, Djamel OUINAS, Zine-Eddine BENNACEUR, Jaime Vina OLAY

Abstract
New pipelines made with composite materials have to be well-designed for better mechanical performances. Recommendations for sizing stratified pipes have been proposed for different combinations of loads. In this context, our paper focus on buckling on laminated composite pipes, using numerical simulation. As a first part, we study free-defect pipes buckling for different pipe diameters, wall thicknesses and fibers orientation. In a second part, we evaluate the influence of defects (notches and crack due to notches), their parameters (size, orientation) and mechanical constraints (pipe under pressure, boundary conditions) on the structure. Results show a strong dependence of the size of the notch to the stability of the structure, amplified by the fibers orientation. Thus, for fibers oriented at an angle close to 20°, pipes manufacturing under these conditions show a particular strength of the structure. The crack length (independently on its orientation) seems to have no significant effect on the buckling factor and therefore the structure integrity, for transverse-orientated fibers and while their orientation go beyond 40°. The main variations are observed when fibers orientation is in the range from a few degrees up to 40°. Results are and discussed according the orientation of crack and fibers.
Date accepted : 2019-06-14

Laboratory study on the effects of hydraulic and granulometric parameters on the response of granular soil to internal erosion
Kamel MENAD, Hanifi MISSOUM, Karim BENDANI

Abstract
Erosion is a major environmental problem to agricultural land as well as to civil engineering infrastructures. Rainwater infiltration into granular soils can lead to the migration of fine particles by suffusion. This experimental study is conducted to evaluate the susceptibility of cohesion less soils to erosion. The soil under investigation was collected from the coastal region of Mostaganem (West of Algeria) where erosion has recently caused several damages. To assess soil instability to erosion, two approaches have been proposed in the literature: the geometric approach and the hydraulic approach. Few studies have examined the combination of the two methods. The objective ofthis study is to combine the two approaches by determining the critical hydraulic load responsible for triggering erosion as a function of soil characteristics. An experimental parametric study was conducted to determine the influence of initial amount of fines, hydraulic gradient and axial stress on the initiation and evolution of suffusion. A combination of the interactions between these parameters allowed us to express the critical hydraulic gradient and to identify the hydraulic behavior of the soil according to the studied parameters. This approach can better estimate the erodibility of cohesionless soils. It can be used in design processes linked to site management.
Date accepted : 2019-06-23

Designing a new model of a seismic base isolator system to Improve the behavior of the stuctures
Khelladi Mohamed, Abed Mohamed, Rebhi Redha

Abstract
Before investigting the dynamics problem of the isolation system, the isolator parts of the model can be solved analytically by using different approaches. In order to calculate the deformation of any element of the isolator due to a compressive vertical load, the analysis will be mainly focused on the principal instability region to determine all aspects of deformations which can lead to eventual frictions coefficient, this region is located at the interaction contact point between the elements. The design is based on the contact point developped by different approaches. In the present study, the mathematical analysis methods by using formulations can approve the different dimensions and deformations of the elements of the system and can be confirmed by the finite element using the Ansys program.  After ensuring the adequate dimensions of the different parts of the isolator system from the analysis, the system can be applied on the structure.This technique can reduce significantly the displacements and accelerations at the underground level which uses a new seismic isolation model, it is an uncoupled system between the structure and the underground. The main objective of this research is to design a new model that doesn't trasmit any force to the structure under horizontal direction chargement on it and it must remain operational and keep the superstructure fixed.
Date accepted : 2019-09-25


Replacement of Sand with Bauxite Mining Waste in Concrete Production
Humphrey Danso, Joseph Kent Boadi

Abstract
The use of natural sand as fine aggregate in concrete is becoming problematic due to scarcity and pressure on mining of the resource. Alternate sources such as the use of industrial waste as replacement of natural sand in concrete are gaining popularity as a sustainable construction material. The aim of this study is to examine the possibility of using bauxite mining waste as a fine aggregate replacement for concrete production. The quantity of sand replaced with bauxite mining waste used are 0, 25, 50, 75 and 100%.  Cube, cylinder and beam specimens were moulded and cured for 7, 14, 21 and 28 days, and tested for density, compressive strength, tensile splitting strength and flexural strength. The study found that there was a slight increase in density of bauxite mining waste produced concrete over the control as the quantity of bauxite residue increased. The study further revealed a significant increase in compressive, tensile splitting and flexural strengths of the concrete produced with bauxite residue as compared with the control, with an increase between 60.3 and 65.5%. Additionally, a good correlation was established between the test types and the density of concrete produced with bauxite mining waste, recording R2 values between 0.9749 and 0.9896. The 100% bauxite residue replacement of sand obtained the highest strength properties in the concrete. The study, therefore, concludes that it is feasible to use bauxite mining waste as a fine aggregate replacement in concrete production. It is recommended that further studies should be conducted on the durability properties of concrete produced with bauxite mining waste as the current study only focused on the strength properties.
Date accepted : 2019-09-25


Effect of Environment with Heavy Industrial Pollution on the Selection of Concrete Mix for Building Structures
Anwar Ul-Hamid, Huseyin Saricimen

Abstract
This study proposes durable concrete mix design suitable for use in superstructures of an industrial plant of a cement company located in an area marked by heavy industrial pollution.  Concentration of pollutants in the environment was recorded by undertaking ambient air quality monitoring along with an assessment of corrosivity of soil and ground water present at the site.  Type of reinforcement, concreting procedures and protection methods were determined for reinforced concrete that was intended to be used in conjunction with steel structures.  Experimental results indicated that soil and groundwater constituted no risk for the substructure.  However, air was highly polluted and deemed to be severely corrosive due to the presence of chloride and sulfate salts, SO2 and CO2 in concentrations recorded several times higher than at a comparable industrial area.  A concrete mix design suitable for observed conditions was recommended.  Additionally, it was suggested that concrete reinforced with black steel bars should be completely coated while that using FBE coated steel bars should be coated up to a height of 1.5m from the grade level for protection against ingress of salt and water.
Date accepted : 2019-10-05

Elaboration and characterization of spherical carbon nanoparticles
SEDIRA Sofiane

Abstract
In this paper, hydrothermal method was used to provide stable colloidal suspension of spherical carbon nanoparticles (CNPs) with good uniformity of size and shape. XRD analyses showed the formation of crystalline structure of carbon material. CNPs Raman spectrum indicates the high quality with a low content of structural defects and high graphitic degree. The formation of CNPs is confirmed by an absorption peak at 264 nm. XPS technique showed well a significant decrease of oxygen containing functional groups, indicating a low degree of graphite oxidation. The active surface area of CNPs was measured by BET technique. TEM images show that CNPs are nearly spherical in shape and the diameters varying between 50 and 120 nm. The CV behaviors showed that CNPs exhibit the higher specific capacitance values, and is greatly improved over that of previously reported carbon nanomaterials.
Date accepted : 2019-10-06

Analysis of static behavior of a P-FGM Beam
Abdelbaki Chikh

Abstract
In this paper, the systematic arrangements are acquired to foresee the static behavior of the P-FGM beam and which have been gotten by Navier's solution. The numerical outcomes got by the new shear models are presented and compared with those available in the literature to see the influence of the geometry and the mixing law on the static behavior of this type of FGM beams.
Date accepted : 2019-10-06

Reliability Based Robust Design Optimization Based On Sensitivity And Elasticity Factors Analysis
Naoual  Karar, Ahmed Felkaoui, Farhat Djeddou

Abstract
In this paper, a Reliability Based Robust Design Optimization (RBRDO) based on sensitivity and elasticity factors analysis is presented. In the first step, a reliability assessment is performed using the First-and Second Order Reliability Method (FORM)/ (SORM), and Monte Carlo Simulation. Furthermore, FORM method is used for reliability elasticity factors assessment, which can be carried out to determine the most influential parameters, these factors can be help to reduce the size of design variables vector in RBRDO process. The main objective of the RBRDO is to improve both reliability and design of a cylindrical gear pair under uncertainties. This approach is achieved by integration of two objectives which minimize the variance and mean values of performance function. To solve this problem a decoupled approach of Sequential Optimization and Reliability Assessment (SORA) method is implemented. The results obtained shown that a desired reliability with a robust design is progressively achieved.
Date accepted: 2019-10-08

Microstructural study of Styrene Polyacrylic (SPA) latex modified mortars
Hichem BERKAK, Zoubir MAKHLOUFI, Madani BEDERINA

Abstract
In this paper, the influence of the styrene polyacrylic (SPA) latex polymer on the microstructural properties of limestone mortars has been studied. For this purpose, five mortars were developed with different dosages of the SPA latex (0%; 2.5%; 5%; 7.5% and 10%) by weight of cement. This research was carried out using XRD, FTIR, and SEM analyses. The results of XRD and FTIR studies showed that the addition of SPA latex can increase the portlandite content of polymer-modified mortars (PMMs), compared to the control mortar. In addition, the moist environment promotes the Ca(OH)2 consumption in PMMs at early age and accelerates the hydration. Moreover, the SEM analysis revealed that the cement hydrate structure of the reference mortar is loose. In contrast, the hydrates of the PMMs were covered by a polymer film or membrane, and the pore structure is significantly affected by the filling effect the micropores by the latex particles.
Date accepted: 2019-10-29

Mechanical instability of saturated soils sampled in the Oran coast, Algeria
Mohammed BOUSMAHA, Mohamed BENSOULA, Renaud TOUSSAINT

Abstract
Soil liquefaction is a significant natural hazard associated with earthquakes. Some of its devastating effects include tilting and sinking of buildings and bridges, and destruction of pipelines. Conventional geotechnical engineering assumes liquefaction occurs via elevated pore pressure. This assumption guides construction for seismically hazardous locations, yet evidence suggests that liquefaction strikes also under currently unpredicted conditions. We show, using simulations and experiments, another mechanism for liquefaction in saturated sandy soils, without high pore fluid pressure. In this work, the objective is to follow and characterize the vertical displacement of an intruder on a dry and saturated mass of soil in laboratory experiments. The external excitation is operated by regular horizontal oscillations with controlled frequency and amplitude. The liquefaction is shown to have a direct impact on the vertical displacement of intruders. It can be concluded that the movement of the intruder depends essentially on the imposed acceleration and the relative density of soil.
Date accepted : 2019-11-10

Comparison of Compressive Strength and Flexural Capacity between Engineered Cementitious Composites (Bendable Concrete) and Conventional Concrete used in Bangladesh
Munshi Galib MUKTADIR, M I Fahim ALAM, Asifur RAHMAN, Mohammad Robiul HAQUE

Abstract
The Engineered Cementitious Composites (ECC) is made of the same ingredients as in regular concrete. The coarse aggregate is replaced with tiny Polyvinyl Alcohol fibres. This structure offers maximum flexibility and it is expected to cost less. It looks exactly like normal concrete, but under excessive strain, the ECC concrete allows, the specially coated network of fibre in the cement to slide within the cement, thus avoiding the inflexibility that causes brittleness and breakage. As this is a special type of concrete there are no defined codes for it, thus for these reasons, the parameters needed are to be obtained using trial and error method. During the composite preparation, sieve analysis was carried out. Composites were reinforced with Polyvinyl Alcohol (PVA) at the following ratios: 0 % (control), 0.5 %, 1 % and 1.5 %. The cylindrical specimens were subjected to compression and the slab specimens were subjected to flexural test using a Universal Testing Machine, while acquiring data with GOM Correlation Software. Test results reveal that fibre ratio 1% is most acceptable for attaining best compressive strength along with high flexural value. Even though 1% fibre content concrete in the flexural strength test showed 33% less strength of what 1.5% fibre content concrete gained, in the long run, for having the highest compressive strength value (almost 62% more than of 0% fibre content concrete and 15% more than of 1.5% fibre content concrete), 1% fibre content concrete is most suited for constructions.
Date accepted: 2019-11-10

Behaviour of ground cupola furnace slag blended concrete at elevated temperature
Stephen Adeyemi Alabi

Abstract
Fires adversely affect the performance of concrete when expose to extreme temperatures. However, it is important to study the effects of elevated temperature on the concrete properties. Concrete often contains other cementitious materials such as ground granulated blast furnace slag (GGBFS) and this has been successfully used to improve its properties. Hence, little or no study has been carried out on the use of ground cupola furnace slag (GCFS) in concreting. Therefore, this paper investigates the behavior of concrete blended with GCFS at elevated temperatures. A total of 300 samples were prepared with four different GCFS contents. The test specimens were cured for 28-d and 56-d and subjected to elevated temperatures ranging from 200oC to 800oC up to 24 h. The slump, residual compressive and tensile strength tests were carried out on fresh and hardened concrete. The results showed that the compressive strength and splitting tensile strengths of concrete generally increased with increasing % GCFS content but decreased as temperature increases. At 28-d and 56-d, the strengths were observed to be maximum at 10% replacement when the temperature is 200oC compared to other mixes. It can be concluded that the strength drastically decreased at temperature above 200oC. An analysis of variance (ANOVA) was also carried out to determine the effect of the elevated temperature and percentage replacement of cement with GCFS on the 28-d and 56-d compressive strength of concrete. The results showed that temperature and % GCFS content had a statistically significant effect on the concrete performance. Based on Tukey’s honestly significant difference (HSD), the effect of GCFS was found to be statistically non-significant for 4% and 6% GCFS content at 28-d; and 2% and 4% GCFS content at 56-d. The effect of temperature was also found to be statistically non-significant for 600oC and 800oC at 28-d; and 27oC and 600oC; 200oC and 400oC at 56-d.
Date accepted: 2019-11-19

The Effect of Masonry Infill Walls on the Reinforced Concrete Frames Behavior under Lateral Load
Ismail LAYADI, Ali MESSABHIA, Jean-Patrick PLASSIARD, Olivier PLE

Abstract
The reinforced concrete structures with masonry infill walls are widely used to construct buildings in Algeria, as in many parts of the world. According to earthquake analysis, this type of construction can undergo serious damage under seismic load. The interaction between the infill wall and the surrounding reinforced concrete structure is considered a key parameter, which could trigger damage and even collapse in self-stable frame buildings. To study the behavior of this type of structures and the wall–frame interaction, four half-scale single-storey, single-bay reinforced concrete infilled and unfilled frames were constructed and tested under in-plane lateral load. Furthermore, the experimental results were analyzed using the Digital Image Correlation (DIC) technique giving a detailed analysis of displacement and strain fields. The wall–frame interaction was evaluated in terms of displacement field evolution and interface slip in the contact contour. The masonry infill wall demonstrated a significant influence on the in-plane lateral response of this type of structure. The analysis of the results of the experiment are discussed in this paper.
Date accepted : 2019-12/02