Evaluation of Documentation System in Iraqi Construction Projects

In Iraq, the construction industry is considered one of the main sectors that contribute strongly to the Iraqi economy. Documentation is a process of collecting documents from past and current works of corporations, then archiving and classification of information to become easy and useful for reuse in the future. The aim of this study is to investigate the reality of documentation in the Iraqi construction industry and how to improve archiving and classification of documents and how documentation can be useful used in contractor and consultant corporations. This research has been conducted through literature reviews followed by a field survey. 80 questionnaires were distributed to contractors and engineering offices. 70 useful questionnaires were received from respondents with an 87% response rate. The findings indicated that the construction projects in the Diyala governorate are applying documentation. The study found that foundations classified and updating the documents as printed and written files and computer files, but foundations lack computer programs and web models for easy archiving and discovery of documents, documentation system currently used doesn't prevent Confusing, conflict in schemas because they still used Auto CAD and paper documentation. The large number and accumulation of paper documents are also considered the most often problem in the documentation system currently used, and construction projects don't have a database for all information related to projects where, it is limited to cabinets full of paper documents, which causes a waste of time and effort when searching for any document or information related to the projects. The study recommended that companies and foundations have to increase cost and effort consumed in the documentation process, improve the owner and staff abilities in computer and web applications, assign a key person for collection and archiving project documents, establishing an internet website for companies, or using cloud applications for storage of documents and sharing information.

Numerical Assessment of a Sustainable Blast Protection Wall

Terrorist attacks have increased in the past few years in different countries. Explosions are problem that has significant impact on human life, as well as the social and economic situations. Engineers have designed targeted structures to mitigate blast effects. However, design blast-resistant systems is pricey and not suitable choice in most cases. Therefore, install blast barriers to protect occupants and instructed can reduce casualties and losses. Most current studies have investigated the performance of multi-layer composite blast barriers composed of advanced materials, which is not only costly, but require skilled labour to construct. The present study conducts numerical analysis of eco-friendly composite blast protection wall to mitigate blast. The wall structure consists of two face-sheet of adobe brick and core layer of crushed recycled aggregate. The analysis framework includes three different blast wall models using ABAQUS®. The explosive charge of 1-kilogram TNT is placed at different standoff distances from 0.25 to 4.0 meter in front of the wall. The authors conclude sustainable materials to design blast barriers could be effective in reducing the intensity of explosions in certain blast scenarios. The thickness of the core layer and standoff distance have the main contribution to identify the blast response of the blast wall. For instance, the calculated out-of-plane displacement results showed when 1- kg TNT place at 0.5-m from the wall, and thickness of the core increases from 30-cm to 60-cm, the displacement decreases by 38.74%. While the acceleration decreases by 75% for the same range of increase of thickness of the core layer. The present study calls researchers to investigate the performance of low-cost, and environment-friendly materials to attenuate abnormal loads wether are man-made or natural hazards.

Reinforced Concrete Circular T-Shaped Deep Beams – Finite Element Investigation

The current work investigates the behavior and strength of T-shaped cross section ring deep beams through a Finite element parametric study. Currently, ring diameter, loading type, concrete compressive strength and number of supports are taken into consideration. It is found that increasing ring diameter of beam by 12.5-25% leads to increase the maximum positive moment, maximum negative moment, maximum torsional moment and midspan deflection by 1.1-2.2%, 2.2-4.3%, 3-6% and 16-33%, respectively, while the load ultimate capacity increases by 11-17%. The positive and torsional moments at midspan and midspan deflection decrease by 23-36%, 3-11% and 6-14%, respectively when the loading type varies from concentered to full uniformly load over a span length of 33, 50, 67 and 100%, respectively. In a related context, this change in load type leads the negative moment at support and the load ultimate capacity to increase by 2-21% and 6-85%, respectively. The midspan positive moment, negative moment, torsional moment and load ultimate capacity increase by 20.4-71.3%, 20-69.7%, 15.6-43.8% and 21-73%, respectively, whereas deflection decreases by 1.4-11%, when increasing the compressive concrete strength by 45-190%. Finally, it is found that the load ultimate capacity increases by 82-348%, when number of supports increases by 25-100%, while torsional moment, maximum positive moments, maximum negative moments and midspan deflection decrease by 11-50%, 38-76.4%, 38.6-76.8% and 14-39%, respectively due to this increase in the number of supports.

Optimizing And Comparative of Polymer-45S5BG and Polymer- HA Coating by Electrophoretic Deposition (EPD)

In this study, two systems of bio-ceramic coating (45S5 bioactive glass and hydroxyapatite) were used in order to compare between them for biomedical applications. Each system consists from two layers of coating done by electrophoretic deposition (EPD) technique on 316L stainless steel material as substrate. Two types of biopolymer were used (Chitosan with Gelatin) as first layer of coating. Taguchi approach with L9 array was used in order to choose the best conditions (concentrations, voltage and time) for coating layers. Each system consists of two layer (biopolymer (first layer) and bioceramic (second layer)) materials. The optimum parameters for first layer of biopolymer was (3g/L concentration, 20 voltage and 3 minute) while optimum parameter for second layer (6g/L concentration, 30 voltage and 1 minute) for two bioceramic group. Zeta potential test were employed to measure suspensions stability. The tape test method was used to evaluate the adhesion between substrate and coating layers, the results show that the percentage of removal area for optimum coating layer (biopolymer, 45S5 BG and HA 8.06%, 10.668%, 6.23% subsequently). XRD inspection was used for identify the phases of coating layers. The Cyclic polarization test was used for evaluation of pitting corrosion resistance, the results show all layers gives good corrosion resistance but 45S5BG gives the best corrosion resistance when compared with HA system.

Experimental analysis of composite materials leaf spring used in automotive

product modifications or replacement of old products with new and improved material items. Vehicle suspension systems are another area where these developments are carried out on a regular basis. More efforts are being made to improve the user's comfort. Appropriate combination of comfort riding attributes and economics in leaf spring production becomes an evident requirement. Many changes have been made to the suspension system throughout time in order to enhance it. Some of the most recent suspension system innovations include the invention of the parabolic leaf spring and the usage of composite materials for these springs. The implementation of composite materials by replacing steel in conventional leaf springs of a suspension system. Composite material having a lot of good properties like simple fabrication, low weight and low cost to performance .The purpose of this study is to investigate the structural properties of a hybrid leaf spring consisting of 95% Epoxy, 5% carbon, 5% glass fiber, and 5% hybrid carbon-glass fiber composite. The various specimens were produced using the manual layup method, specimen were subjected to tensile, hardness, and fatigue tests, with all data reported and compared. The experimental results showed an increase in Hardness, Tensile, and fatigue life when the reinforcing fibers are applied. The best results of the mechanical test obtained when hybrid reinforcement was applied.

Improvement of the Mechanical Characteristics of Fiber Metal Laminate (FMLs) Used for Aircraft Wing Using Epoxy-Resole

The Fiber Metal Laminates (FMLs) was studied and improved the mechanical properties were used for aircraft wing. The FMLs are consisting of metal sheets reinforced with fiber bonded by matrix phase. The FMLs consist of seven layers to produce the Hybrid composite materials that made from 2024-T3 Aluminuim sheets with carbon and glass fibers as reinforcement and bonded using adhesion materials that are locally manufactured from resole resin with adding using epoxy resin. By using the FMLs, the mechanical characteristics have been improved and the weight of the aircraft wing has been reduced. The mechanical characteristics have been improved comparing to other FMLs using commercial epoxy. The FMLs with carbon and glass fibers have high tensile strength and elastic modulus but low yield and elongation comparing with the FMLs of carbon fibers as a reinforcement. The flexural modulus and impact toughness is high for the FMLs with glass fiber comparing with jute fibers with adding using carbon fiber as areinforcement.The Aramid Reinforced Aluminum Laminates (ARALLs) have low fatigue strength than FMLs using carbon fiber as reinforcement. The FMLs are lower ratio of ultimate to yield strength and density than 2024-T3 Aluminum alloy that commonly used in aircraft wing.

Reactive Powder Concrete Beam's Behavior in Flexural : Review

Reactive Powder Concrete can be considered as a special type of concrete in which the coarse aggregate will be eliminated to get a homogenous microstructure with a maximum density for final result. Many researchers presented a state of the art review on reactive powder's production, mechanical properties, durability, development and applications. But the review about structural behavior is hardly to found. Because of importance of this type of concrete and its structural applications. This paper focused on review the researchers that deals with structural behavior of reactive powder concrete beams under bending load. Also review the proposed design equations related with reactive concrete behavior. Before starting a review of strength , stress-strain relation and ductility are presented because of their importance and effect on structure behavior of beams under bending. According to review of previous studies the type of fibers and its content as volumetric ratio, type of pozalanic materials and its content , amount of longitudinal steel reinforcement are main factors that affected the flexural behavior of reinforced Reactive Powder Concrete

Cyclic Loading Response of Composite Corrugated Steel Plate Shear Walls - Smart Technic

The structural element within the whole structure contains structural elements like beams, slabs, columns and reinforced concrete walls. One of the most vertical structural elements is shear wall that built to giving stability to the building, resisting lateral force such as earthquake and wind and to reduce the building deformations. In present study, the analysis of corrugated vertical steel plate shear walls using finite element method by ABAQUS software is examined. Four different modes are analysed in which the first model is vertical corrugated steel shear wall plate, second is the composite shear wall with full interaction, third is the composite shear wall and finally the fourth model is composite shear wall with gap between concrete panel and steel frame to check out the full performance of different shear wall under the effects of cyclic loadings. Displacement, drift and energy dissipation will investigate throughout analysis. Analysis results indicated that the gap and composite action between steel and concrete panel play an important role on the performance of shear wall under cyclic loading. The decrease in displacement of composite shear wall as compared with the steel shear wall reach 11.86%.

Sensitivity analysis for dam breach parameters using different approaches for earth-fill dam

The prediction of dams breach geometry crucial in studies of dam breaking. The hydrographs characteristics of flood that resulting from breaking of dam is mainly depend on the geometry of breach and the time formation of breach. Five approaches (Froehlich, Macdonald and Langridge-Monopolis, Von thun & Gillete, USBR and Singh % Snorrason) was used in order to predict dam breach parameters (breach width, breach side slope, breach formation time). The Sensitivity analysis was performed in order to assess the effect of each parameter on the resulting hydrograph of the flood. HEC-RAS model was used to calculate the effect of each parameter on the hydrograph of the flood that resulted. The width of breach (Bavg), side slope (z) and formation time of breach (tf) increased by 25%, 50%, 75% and 100% and decreased by 25%, 50% and 75%, respectively. Flood hydrograph was estimated at the dam site for each case. Sensitivity analysis was performed in order to check the effect of each parameter of breach and time of breaching. Sensitivity analysis was performed with Froehlich method with the mode of overtopping failure and maximum operating level at 107.5 meter above sea level. Result of sensitivity analysis show that peak discharge and time to reach it is adequately sensitive to breach side slope, highly sensitive to the breach formation time and less sensitive to breach width.

Behavior of Reactive Powder Concrete Beams Exposed to Fire

In this paper, the effect of direct fire flame and steel fiber ratio on some mechanical properties and behavior of the relationship between load and deflection of rectangular reinforced concrete beams under the influence of fire exposure was studied. Concrete specimens were exposed to fire at temperatures ranging from (25- 400 ºC). Three temperature levels of (200, 300, 400 ºC) where chosen for exposure duration of 2.0 hours. After conducting the test, it was found that increasing the proportion of steel fibers in percentages 0.5% to 1% and 1.5% decreases the mid-span deflection at service load by 33%, 50% and 37.5 and increases the ultimate load by 36.36%, 41.6% and 53% respectively. After the beams are exposed to fire, it was noticed that the maximum crack width increases with increasing fire temperature.