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Effect on the Compressive Strength of Mortars Using Ground Granulated Blast Furnace Slag as a Partial Replacement of Cement

Abstract

Mortar is widely used in the construction industry for different purposes. Its compressive strength is the main parameter which is brought under focus. Compressive strength of mortars depends upon many factors such as water-cement ratio, fine aggregates size, and different curing conditions. This experimental study was undertaken to investigate the effect of GGBFS on compressive strength of mortars under different curing regimes using GGBFS as a partial replacement of cement. A total of 60 cubes of standard size of 2 x 2 x 2 inches were casted in laboratory, out of which 12 cubes each were prepared with 0%, 5%, 10%, 15% and 20% GGBFS replacement for cement. Cubes were cured for 3, 7, 14 and 28 days. Bases on obtained results it is observed that the maximum compressive strength was achieved by sample with 5% GGBFS, although 10% GGBFS samples achieved higher compressive strength than the control sample with 0% GGBFS. Further replacement beyond this value causes reduction in strength.

Open access
Effects of Electromagnetic Fields and their Shielding on the Quality of Carrot (Daucus Carota L.) Seeds

Abstract

The aim of the study was to determine the effect of electromagnetic fields and their shielding on carrot seed quality. Three sectors were separated on the device emitting electromagnetic fields: “E” - sector emitting electromagnetic radiation with the predominance of the electrical component, “EM” - sector emitting electromagnetic radiation without domination of its components and “M” - sector with a predominance of magnetic component. Fields generated by the device were also shielded with ADR TEX screen, based on a nanocomposite in which the electric component of the electromagnetic radiation is absorbed by water dispersed in a dielectric matrix in various ways. The composites exhibit high dielectric absorption and shield electric fields within the frequency range from ~100 mHz to ~100 kHz. Seed germination and vigour were evaluated at 20 °C in darkness. Mycological analysis was performed using a deep-freeze blotter test. Exposure of seeds to radiation with the predominance of the electrical component and electromagnetic radiation without domination of its components combined with shielding of electromagnetic fields with ADR TEX (E+ADR TEX and EM+ADR TEX) increased seed germination energy and germination capacity compared to these treatments without shielding and control. The percentage of abnormal diseased seedlings in treatments with shielding of electromagnetic fields with ADR TEX (E+ADR TEX, EM+ADR TEX and M+ADR TEX) was significantly lower than in the treatments without shielding and in control. None of the treatments affected seed vigour. Generally, exposure of seeds to electromagnetic radiation did not influence the incidence of fungi.

Open access
An Eight-Node Hexahedral Finite Element with Rotational DOFs for Elastoplastic Applications

Abstract

In this paper, the earlier formulation of the eight-node hexahedral SFR8 element is extended in order to analyze material nonlinearities. This element stems from the so-called Space Fiber Rotation (SFR) concept which considers virtual rotations of a nodal fiber within the element that enhances the displacement vector approximation. The resulting mathematical model of the proposed SFR8 element and the classical associative plasticity model are implemented into a Fortran calculation code to account for small strain elastoplastic problems. The performance of this element is assessed by means of a set of nonlinear benchmark problems in which the development of the plastic zone has been investigated. The accuracy of the obtained results is principally evaluated with some reference solutions.

Open access
Evaluation of Chemical Composition of Essential Oils Derived from Different Pelargonium Species Leaves

Abstract

Plants have been used for their aromatic and medicinal purposes for centuries. The genus Pelargonium contains about 250-280 species and cultivated around the world for the production of essential oils and absolutes. Pelargonium species are remarkable for their odour diversity, from fresh, lemon and minty scent, through floral, rose, fruity up to spicy and camphoreous smell as well as many health beneficial properties, that is why their essential oils are widely used in perfume, cosmetic, food and pharmaceutical industries. The aim of this study was to determine variability in populations of Pelargonium genus by evaluating their differences in quantitative and qualitative essential oils compositions. This study determined that of all the examined essential oil, the one of P. graveolens indoor cultivar has the closest C:G ratio (1.16) which makes it a very valuable product. In comparison with available literature, beside the geographical region of plant growth, all essential oils from P. graveolens contain a diverse range of compounds, nevertheless, in every single one, geraniol and citronellol are present in the most significant fraction of the total oil. The examined P. roseum essential oil was characterized by the highest level of citronellol (44.62 % of total oil), but it can be due to the chemical reactions (conversion geraniol into citronellol) occurring in stored product.

Open access
Examination of the Types of Erosion and Introduction of Protective Measures to Prevent Soil Loss

Abstract

Soil erosion is the most important challenge of the biosphere. Soil is one of the most important and most valuable natural resources. It meets the essential needs of the world. If the soil is not well preserved, then hunger will conquer all over the globe. This article tried to identify types of erosion and provide solutions to prevent it to protect this main material by examining the effects and results.

Open access
Experimental Investigations of Concrete Filled Battened Steel Columns of Different Slenderness

Abstract

The study investigates the axial load behaviour of concrete filled battened steel columns not covered by the design standards. A series of full scale tests on two I-sections connected together with intermediate batten plates and filled with concrete were carried out. The main parameters varied in the tests are length of the members and strength of the concrete filling. One bare steel member was also tested and results were compared with those filled with concrete. The tests results were illustrated by load-strain curves. The main objectives of these tests were twofold: first, to describe behaviour of new steel-concrete columns and second, to analyze the influence of slenderness on load-carrying capacity.

Open access
Experimental Study of the Effects of Flow Discharge, Diameter, and Depth on Shear Stress in a Rectangular Channel with Rigid Unsubmerged Vegetation

Abstract

Shear stress is one of the most critical parameters in hydraulic and coastal engineering, which is often measured indirectly. Since there is no instrument to measure this parameter directly and given that it is usually calculated by measuring other parameters such as velocity and pressure and using some equations, shear stress measurement is often accompanied with large measurement errors. In this study, a new technique and direct measurement using physical modeling in a hydraulic knife-edge flume and load cell were employed to measure the shear stress in a rectangular channel with rigid unsubmerged vegetation with Dv= 20, 25, and 32mm in

Q=25 and 30 Lit/S and y=10, 12, 17, and 20 cm. The results indicate that the shear stress and the dimensionless τ0τ ratio decrease in a constant flow discharge with increasing the flow depth. It was also shown that the shear stress would be enhanced with an increase

in vegetation diameter due to increasing vegetation density against flow. According to dimensionless ratios of τ0τ and Dvy in the graphs and considering the trend lines with appropriate correlation coefficients, some equations were presented to calculate the shear stress in the concerned range.

Open access
Experimental Testing of Some Polymer Materials

Abstract

The research aims to test polymer materials as the plastic materials: UHMWPE and POM, to observe there characteristics, to determing how they can be used and what we can obtain from them. We wanted to see the strong and the weak values that characterize them, what kind of parts we can produce from them and in what case we can use it. By applying this tests is necessary in order to see real datas that can help you compare them, and lead you to conclusions. Using these methods of testing materials leads to the establishment of real properties of the material and to the establishment of new configurations necessary to be made to the manufactured parts.

Open access
Experimental Tests of Steel Unstiffened Double Side Joints with Flush and Extended End Plate

Abstract

Experimental tests of steel unstiffened double side bolted end-plate joints have been presented. The main aim of the conducted tests was to check the behavior of joints in an accidental situation and possibility of creating secondary mechanism, i.e. catenary action in the scenario of column loss. Two types of end plate joints were tested: flush end-plate (FP) and extended end-plate (EP) with different thickness and different number of bolt rows in each. The tests were carried out on an isolated cross beam-column-beam type system until joint failure. During tests the available moment resistance and rotation capacity of bending joints and also values of tension forces in the beam were determined. The joints with extended end-plate have demonstrated higher bending and rotational capacity than flush end-plate. Significant deformation of column flanges, web and end plate were observed. The fracture of bolts was the failure mode of joints. Obtained results of axial force values in beam exceeded standard requirement what confirmed that the joints with unstiffened web column, flush or extended end-plate possess the ability of development the catenary action.

Open access
Fatigue and Rutting Analysis of Asphaltic Pavement Using “KENLAYER” Software

Abstract

Rutting and Fatigue are taken as main premature failures among all distresses, as these distresses have wide effect on performance of pavement. Sudden variation of heavy axle loaded vehicles, improper mix design and traditional design methodologies used in pavement design industries are major factors behind these failures. For proper performance and good serviceability, these premature distresses should be resisted. Thus, there is a need of using a Mechanistic based design methodology like KENPAVE software, so that traditional design errors should be overcome. KENLAYER is a part of KENPAVE software. KENLYER software tool is utilized to calculated accurately stresses and strains in asphaltic pavement that are ultimately used in calculating allowance for rutting and fatigue failure utilizing Asphalt Institute design models or formulas. Resistance to Rutting failure is checked by calculating vertical compressive stress at the top of soil sub-grade layer, while resistance to fatigue failure is checked by calculating horizontal tensile strain at the bottom of asphaltic layer using KENLAYER software tool. Thus, the object of this research study is to analyze a flexible pavement with respect to rutting and fatigue distresses using KENLAYER software tool. For achieving that objective NHA (N-55) section of road in Sehwan Pakistan was taken as a reference pavement. Pavement was analyzed by altering the thicknesses of bituminous courses by ± 25 percent. From that we obtained total 20 cross-sections to be analyzed using KENLAYER software in terms of Rutting and Fatigue premature failures.

Open access