Jet grouting is one of the most widely applied soil improvement techniques. It is suitable for most geotechnical problems, including improving bearing capacity, decreasing settlement, forming seals, and stabilizing slopes. One of the difficulties faced by designers is determining the strength and geometry of elements created using this method. Jet grouted soil-cement columns in soil are a complicated issue because they are dependent on a number of parameters such as soil type, grout and water flow rate, rotation and lifting speed of monitor, nozzle jetting force, and water to cement ratio of slurry. This paper discusses the effect of the water-cement ratio on the physical and mechanical characteristics of soilcrete. In the laboratory, sandy soil mixed with cement grout with water-cement ratio varies from (0.7:1 to 1.4:1). To evaluate the characteristics of soilcrete, 96 specimens were prepared in the laboratory and tested at different curing times. The results indicate that the Uniaxial Compressive Strength (UCS) of soilcrete decreases with increasing the (W/C) ratio of the grout, where the soilcrete strength of W/C ratio of 0.7 is higher about 237% of W/C ratio of 1.4 at 28-day; the evolution of the (UCS) is proportional to the logarithm of the curing time; the ratio between the modulus of elasticity (Etg50) to the maximum UCS varies from 113 to 175; when the water-cement ratio increases, the dry density of soilcrete decreases, as a result, the (USC) of soilcrete decreases.
The vacancy of natural resources is undoubtedly limited by time. The sustainable development principle recommends modern technology for its protection and renewal. This project conducted analyses on two underground water sources in the north of Algeria (Mechroha Province). Besides, the use of the hardness factor and the adoption of the titration method, which is the determining the concentration of an unknown solution using a known solution concentration, have permitted the characterization of the examples taken and to verify their conformity to the standard required, the results found showed HT=6.66 French degrees (oF) ) for Ain Guilloume water spring in comparison to Ain Messai water spring H
Background: The aim of the study was to investigate the effect of surface treatments of zirconia (grinding and sandblast with 50μm, 100 μm) on shear bond strength between zirconia core and veneering ceramic. Material and methods: Twenty-eight presintered Y-TZP ceramic specimens (IPS e.max ZirCAD, Ivoclar vivadent) were fabricated and sintered according to manufacturer’s instructions. The core specimens were divided randomly in to 4 groups, group 1: no surface treatment, group2: zirconia specimens were ground with silicon carbide paper up to1200 grit under water cooling, group3: zirconia specimens were ground and sandblast with 100 μm alumina, group 4: zirconia specimens were ground and sandblast with 50 μm alumina. Surfa
... Show MoreThis study was carried out to estimate the effect of shaliness on water saturation from TN field of Niger Delta. The conventional Archie and the Shaly-sand water saturation models was used in the evaluation of wells. Two sand bodies (Sand 01 and 02) were mapped with thicknesses range from 76.8ft to 119.3ft across the three wells for Sand 01 and 187.5 to 339.9ft across wells TN_1 and TN_4 for Sand 02. The cross plot of the effective porosity (φe) versus volume of shale (Vsh) show a decrease in the effective porosity with an increase in shale volume. This reveals a laminated shale pattern across the reservoir sands. The estimations from the conventional method and the Shaly-sand models of Simandoux and Indonesia show a clear disparity due
... Show MoreThe lead-acid battery has become so dependable in its used applications of automobile starting, emergency lighting and telecommunications, which left an impression that no further investigation is necessary or desirable. While there has been slow continuous improvements in lead-acid battery performance and mainly limited to design and material engineering. This work is mainly devoted to the properties of the active mass of the positive electrode and the acid/water ratio during the manufacturing process. A field study is carried out at the State Battery Manufacturing Company located in Baghdad, to prepare batches of lead mono-oxide with predefined quantities of liquid additives (i.e. sulfuric acid and water). Quality control and laborator
... Show MoreDate palm fiber is one of the common wastes available in the M. E. countries essentially Iraq. The aim of search to investigate the performance and effects of fiber date palm on the mechanical properties of high strength concrete, this fiber was used in three ratio 2, 4 and 6 % by vol. of concrete at ages of (7, 28, 90) days. Results demonstrated improvement in the compressive strength increased 19.2 %, 23.6%, 24.9 % for 2%, 4%, 6% of fiber respectively at age 28 days. Flexural strength increases 47.6%, 66.2%, 93.8% form (2,4,6) % of fiber respectively at age 28 days. Density increase about 0.41%, 0, 61 % 0.69 % for (2,4,6) % of fiber respectively at age 28. Absorption water decrease
This paper studies the behavior of axially loaded RC columns which are confined with carbon fiber reinforced polymers’ sheet (CFRP) and steel jackets (SJ). The study is based on twelve axially loaded RC columns tested up to failure. It is divided into three schemes based on its strengthening type; each scheme has four columns. The main parameters in this study were the compressive strength of the concrete and steel reinforcement ratio. Furthermore, the results of the experimental test showed a substantial enhancement in the column's load-carrying capacity. When compared to the original columns, the CFRP sheet had a significant effect on improving the ductility of the column by increasing the axial deformation by about 59.2 to 95.7
... Show MoreIn this work, the effect of variation of semi-angle of the conical part on the vibration characteristics of cylindrical-conical coupled structure is investigated. The shell is made of polyester resin reinforced by continuous E-glass fibers. The case is analyzed experimentally and numerically for orthotropic shell structures. The experimental program is conducted by exciting the fabricated structure by an impact hammer and monitoring the response using an attached accelerometer for different semi-angles of the conical part.
Software named SIGVIEW is used to perform the signal processing on the acquired signal in order to measure the natural frequencies and the corresponding mode shapes. The numerical investigation is achieved using ANS
Irrigation scheduling techniques is one of the suggested solutions for water scarcity problem. The study aims to show the possibility of using practical and applicable irrigation scheduling program which was designed by Water Resources Department at the University of Baghdad by using Spreadsheet Formulas for Microsoft Excel program, version 2007, with some modification to generalize it and made it applicable to various climatic zone and different soil types, as a salvation for the shortage of irrigation water inside the irrigation projects. Irrigation projects which incidence of Tigris River basin will be taken as an applicable example. This program was based on water budgeting and programmed depending on scientific concepts which facili
... Show MoreThe assessment of a river water’ quality is an essential procedure of monitor programs and isused to collect basic environmental data. The management of integrated water resources in asustainable method is also necessary to allow future generations to meet their water needs. Themain objective of this research is to assess the effect of the Diyala River on Tigris River waterquality using Geographic Information System (GIS) technique. Water samples have beencollected monthly from November 2017 to April 2018 from four selected locations in Tigris andDiyala Rivers using the grab sampling method. Fourteen parameters were studied which areTurbidity, pH, Dissolved Oxygen, Biological Oxygen Demand, Electrical Conductivity, TotalDissolved Solids,
... Show MoreThe assessment of a river water’ quality is an essential procedure of monitor programs and is used to collect basic environmental data. The management of integrated water resources in a sustainable method is also necessary to allow future generations to meet their water needs. The main objective of this research is to assess the effect of the Diyala River on Tigris River water quality using Geographic Information System (GIS) technique. Water samples have been collected monthly from November 2017 to April 2018 from four selected locations in Tigris and Diyala Rivers using the grab sampling method. Fourteen parameters were studied which are Turbidity, pH, Dissolved Oxygen, Biological Oxygen Demand, Electrical Conductivi
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