Formulation and characterization of self compacting concrete with silica fume

Self-compacting concrete (SCC) was elaborated using local materials and silica fume (SF) as admixture in 15% of cement quantity, two different Portland cements (PC) and two different superplasticizer that the chemical nature is polycarboxylate and plynaphtalene, the aggregates used are (AG 3/8 mm, AG 8/15 mm), coarse and fine sand (SC, SF) witch fineness modulus 3.2 and 1 in the order. The dosage of the different superplasticizer used is chosen after experimental spreading tests of each self compacting concrete formulation. Results of fresh concrete tests executed, as L-box and segregation resistance are on concordance whit values recommended by the French association of civil engendering. Also the mechanical characterization was conducted by compressive strength and splitting compression testing procedure, results values are in the range higher than 20 Mpa at the seven day by the compressive test for the all compositions, and the highest value was 40.93 MPa at the 28 day bay compressive test of the fourth’s formulation specimens, the values of splitting compressive tests of al formulation specimens at 7, 14 and 28 days, was situated between 2.01 and 4.40 MPa. In order to determine the superplasticizer saturation assay in of cement pasts used in self compacting concrete, the stady was completed by a rheological stady with a variable velocity gradient, so as to estimate the quantity of saturation assay of superplasticizer and the formulation, also the flow models of cement past

Influence of boiling temperature on the panels lvl (laminated veneer lumber) quality made with oak ( canariensis) algeria wood

The panels LVL (Laminated Veneer Lumber) are less used in construction, which are produced by peeling trunk of trees, undergone baking operation which one determined the quality of plating and LVL panels made by gluing. Our study here consist to vary the boiling temperatures ranging from 40C°, 50 C°, 60 C°, to 70 C° (two panels are drawn for each temperature, and 14 specimens (20 * 20 * 336mm) for each panels) that was secure settings peeling, speed of rotation of the lathe, pressure bar, clearance angle of the knife and the thickness of the veneer, as we fix the amount of glue 400g / cm2, the pressure pressing the panels in order to clearly identify the influence of baking temperature logs of Algerian oak wood quality. Our controls are carried out by non-destructive testing after that the specimens are tested with destructive method under four point bending, according to the perpendicular direction and parallel plating, and we took into consideration the calculation of Young's modulus and stress at break for each series of panel

Resistance to crack propagation of Algerian wood

Wood is the most building materials widely used since prehistory for the construction of houses, tools, weapons. Accidents occurring during the use of materials caused by different defaults, as: knots, resin pockets, cracks. These various defaults and others are the starting point of the principle of crack mechanics. Our present work focuses on determining the resistance to crack propagation of three types of Algerians wood, (Aleppo pine, eucalyptus and oak), by calculating the energy release rate G (mode I). The estimation of factor G allows the possibility of fracture propagatio

Tylosin Sorption to Silty Clay Loam Soils, Swine Manure, and Sand

The objectives of this study were to assess sorption and desorption of tylosin, a macrolide antimicrobial chemical used in swine, cattle, and poultry production, in three silty clay loam soils of South Dakota and compare soil sorption to sand and manure sorption. The silty clay loam soils, from a toposequence in eastern South Dakota, standardized sand samples, and swine manure were used in 24-h batch sorption studies with tylosin concentrations ranging from 25 to 232 μ mole/L. Desorption from soil was conducted over a four-day period. Partition coefficients, based on the Freundlich isotherm (K f ) or K d values, were calculated. K f values for the silty clay loams were similar, not influenced by landscape position, and averaged 1350 with isotherm slopes ranging from 0.85 to 0.93. K f values for sand were dependent on solution/sand ratios and pH, ranging from 1.4 to 25.1. K d values of manure were dependent on the solution type and ranged from 840 L/kg with urine to about 175 L/kg when sorbed from water. Desorption of tylosin from each soil over the four-day period was \u3c 0.2% of the amount added. The soils\u27 high K f values and low desorption amounts suggest that once tylosin is in these soils, leaching to lower depths may not occur. However, this does not preclude runoff with soil eroded particles. If tylosin reaches a sand aquifer, through bypass flow or other mechanism(s), movement in the aquifer most likely would occur

Utilization of waste glass in the improvement of concrete performance: A mini review

Every year, millions of tonnes of glass waste pose terrible problems related to the environmental condition all over the world. The glass is mainly composed of silica. Its use in concrete could be a beneficial solution for the environment and also economic problems. In this mini review, the different possibilities of the valorization of glass waste by substitution of aggregates and cement in concrete have been explored. Its effects on the physicochemical and mechanical characteristics were examined in the main research in this direction. The use of waste glass in concrete can offer an improvement in concrete performance and an asset for participation in sustainable development by reducing this waste

Wear of Special Treated Tools During MDF Peeling

Tools with chromium nitride coating applied by triode pulverizing have been tested in routing and peeling of wood. The efficiency of coatings was proved in medium density fiberboard cutting, thus in heavy cutting conditions , as well as in routing of OSB (Oriented Strand Board) where a CrN coating of 1microm of thickness allowed to process up to 9 times longer than in case of non-dressed tool [1]. The purpose of this study was to examine the improvement of the tools wear in the peeling of MDF, achieved by special treatment of the tool. The modifications of the active surfaces of knives by applying hard coatings (CrAlN, CrSiN), have already given the promising results in the routing of the MDF [2]. The limiting factor of applying these coatings is their adhesion to the substrate ndashthe cutting tool. For this reason the duplex treatments including nitriding and hard coating deposition were tested Nitriding treatments have been performed inside a low vacuum furnace equipped with an impulsive current generator. The CrAlN coating was carried out by a dual magnetron sputtering system 8NORDIKO type 3500-1356 MHz. The CrSiN films were deposited using DC/RF dual magnetron sputtering system (AC450). In order to study the Si content effect on the CrSiN properties, two targets (50.8 mm of diameter) of Cr (99.99%) and Si (99.99%) were used. ADC and RF (13.56 MHz) generator were used to polarize the Cr and Si targets, respectively. The Cr target/substrate distance was 80mm while the Si target/substrate distance was only 70mm. The CrSiN coating have been prepared by institute FEMTO/ST of Besancon. nbspThe wood machining tests were performed using a laboratory microlathe which permits to make a simulation of the peeling process

Study of halloysite nanotubes/poly(hydroxybutyrate-co-valerate) (PHBV)/poly(butylene succinate) (PBS) ternary nanocomposites

International audienc

Location-Based Analytics in 5G and beyond

Location-based analytics leverage accurate location awareness enabled by the fifth generation (5G) mobile technology standard, as well as the integration of heterogeneous technologies, to empower a plethora of new services for 5G verticals and optimize the use of network resources. This article proposes an end-to-end architecture integrated in the 5G network infrastructure to provide location-based analytics as a service. Based on this architecture, we present an overview of cutting-edge applications in 5G and beyond, focusing on people-centric and network-centric location-based analytics