In recent decades, tremendous success has been achieved in the advancement of chemical admixtures for Portland cement concrete. Most efforts have concentrated on improving the properties of concrete and studying the factors that influence on these properties. Since the compressive strength is considered a valuable property and is invariably a vital element of the structural design, especially high early strength development which can be provide more benefits in concrete production, such as reducing construction time and labor and saving the formwork and energy. As a matter of fact, it is influenced as a most properties of concrete by several factors including water-cement ratio, cement type and curing methods employed.
Because of accelerated curing is deemed one of methods that achieved high early age strength of concrete and has been grown only gradually. So, the prime aim of this research work is to provide information about the some desired properties of superplasticized and retarding concrete succumbed to accelerated curing methods, such as compressive strength and water absorption and compared it with their corresponding normally curing concrete. Besides, the research discusses the influence of surface texture of aggregate and over-dosing for admixture on performance concrete in such as that conditions. The test results revealed that effect of admixture on properties of concrete are dependent upon it dosage, surface texture for aggregate and
temperature used for curing
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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 MoreThis in vivo study was conducted to investigate the effect of different concentrations of ozonated water on experimentally skin infection with some of bacterial isolates (Pseudomonas aeruginosa and Staphylococcus aureus ) which Showed dermal infection in experimental animals after 48 hours of exposure to these Microorganisms. Results revealed that ozone has the power to accelerated the healing process depending on the perfect concentration of ozonated water used and the severity of infection & nature of causative agent , in which the recovering period was 7 days for the infection caused by P. aeruginosa and 5 day for S.aureus by using the concentration 60 µg/ml . Results also indicated in this study the stimulated effect of O
... Show MoreThis paper presents ABAQUS simulations of fully encased composite columns, aiming to examine the behavior of a composite column system under different load conditions, namely concentric, eccentric with 25 mm eccentricity, and flexural loading. The numerical results are validated with the experimental results obtained for columns subjected to static loads. A new loading condition with a 50 mm eccentricity is simulated to obtain additional data points for constructing the interaction diagram of load-moment curves, in an attempt to investigate the load-moment behavior for a reference column with a steel I-section and a column with a GFRP I-section. The result comparison shows that the experimental data align closely with the simulation
... Show MoreThis study aimed at evaluating the torsional capacity of reinforced concrete (RC) beams externally wrapped with fiber reinforced polymer (FRP) materials. An analytical model was described and used as a new computational procedure based on the softened truss model (STM) to predict the torsional behavior of RC beams strengthened with FRP. The proposed analytical model was validated with the existing experimental data for rectangular sections strengthened with FRP materials and considering torque-twist relationship and crack pattern at failure. The confined concrete behavior, in the case of FRP wrapping, was considered in the constitutive laws of concrete in the model. Then, an efficient algorithm was developed in MATLAB environment t
... Show MoreThis study was conducted to know the effect of some phenotype characteristics of corn plant on infection by (CSB), using 13 genotypes of corn plant, planting during autumn season 1997 and 1998. The result revealed that the mean of plant height (with male flowering) was (183-219) cm, the mean of leaf No./ plant in all genotypes was (16-18) leaf but the leaf area of plant was (4350-6249) cm2, there were significant differences of phenotype characteristics between genotypes ,the percentage of infection by (CSB) was (5.9-35.9),% the result showed that the phenotype characteristics had non effect on the infection percentage by (CSB) and the correlation coefficient was not significant.