Print ISSN: 1992-7428

Online ISSN: 2706-686X

Volume 9, Issue 1

Volume 9, Issue 1, Summer and Autumn 2013, Page 1-148

Nonlinear Three-Dimensional Finite Element Analysis of Reinforced Concrete Dapped-End Beams

A. Mohammed

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 1-16
DOI: 10.37650/ijce.2013.80362

This paper deals with the nonlinear finite element analysis of two shear-critical concrete dapped-end beams. Reinforced concrete dapped-end beams having nominal shear span to depth ratio values of 0.56 and 0.59, concrete strength 32MPa and 34MPa, and reinforcement ratio via yield strength 2.83MPa and 7.39MPa, that failed in shear have been analyzed using the ‘ANSYS’ program. The ‘ANSYS’ model accounts for the nonlinearity, such as, post cracking tensile stiffness of the concrete, stress transfer across the cracked blocks of concrete. The concrete is modeled using ‘SOLID65’- eight-node brick element, which is capable of simulating the cracking and crushing behavior of brittle materials. The internal reinforcements have been modeled discretely using ‘LINK8’ – 3D spar element. A parametric study is also made to explain the effects of variation of some main parameters such as shear span to depth ratio, concrete compressive strength, and the parameter of main dapped-end reinforcement on the behavior of the beams. From the present modality the capability of the model to capture the critical crack regions, loads and deflections for various types of shear failures in reinforced concrete dapped-end beams have been illustrated. The parametric study shows that the beams shear strength is affected by the shear span to depth ratio, concrete compressive strength and the amount of main reinforcement.

Thermal behaviour of concrete walls for hot climate region instead of common bricks

Atif Ali Hassan

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 1-18
DOI: 10.37650/ijce.2013.80536

To reduce using the brick as a unloaded walls in frame building by using concrete parts to preproduction walls and is assemble in working area , the suggested wall is consist of a double parts (1000x500x140)mm with 50mm insulating material and arrangement parts by roller bolts with building frame and covered by sheets as external finishing material, and used a gypsum layer of 3mm thickness as an internal finishing material, therefore, the total wall thickness is 200mm.
The thermal behavior of that suggested wall was measured for 15 hour/day for one day in July month. in Baghdad climate region (33.2 N°).
The researcher found that, the metal sheet which paint with thermal & plastic paints cover that suggestive wall is gave more energy saving when it compared with brick wall (240mm,120mm) and the saving value was increased when uses reeds stalks sheay 50mm (thickness) as an insulating material among the concrete wall instead of air gap.

Using Steel Fiber Reinforced Concrete (SFRC) as an Alternative to Negative Reinforcement in Continuous RC Slab Panels

Ali H. Aziz; Mithaq A. Louis; Wissam K. Al-Saraj

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 17-26
DOI: 10.37650/ijce.2013.80364

This study presents an experimental investigation performed to investigate the using of steel fiber reinforced concrete (SFRC) as an alternative to negative reinforcement in continuous RC thin slab panels. More rational way has been used by replacing negative reinforcement near interior supports by steel fiber reinforced concrete (SFRC). Tests were carried out on four slab panels, simply supported under single point loading. One of which were made fully with NSC, and the others were made partially with SFRC in negative moment zone.
Experimental results show that the ultimate load capacity are increased (23% -58%) and the cracking loads are increased (25% -62.5%) for tested specimens strengthened with SFRC, in comparison with the reference specimens. Crack arrest mechanism of steel fibers limits crack propagation, improves the ultimate and tensile strength. So, more practical technique can be concluded from this study and employed in manufacturing of thin slabs.

An attempt to enhance the methods of obtaining the basic solution of the transportation model by introducing some alteration to such method

Abdulsalam Zidan

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 19-36
DOI: 10.37650/ijce.2013.80537

This research aims to propose a new methodology of obtaining the basic solution of the transportation model, which is one of the operations research. Transportation model aimed to find the economic solution to the plan of allocation of products from production centers to consumption centers.
One of the important issues of application the transportation model is the issue of transfer raw materials for construction projects (such as ready-mix concrete) and for which there is usually a set of options for production centers as there is always a group of consumption centers (construction sites). This application was chosen because of the wide use of it and due to its impacts on macroeconomic level.

Started by reviewing the current methods of obtaining the basic solution of the transportation model, then the factors that are not taken into account in these methods have been identified and, accordingly, two methods have been developed to obtain the basic solution of the transportation model. The first method depends on the indicator of the biggest costs of transport between the centers, while the second method uses the cost multiplied by the amount transmitted (actual cost) as an indicator to determine the basic solution of the transportation model. Unlike other methods, this method considers all variables mentioned in the objective function.

Finally, the proposal method has been illustrated by the use of an empirical example.

Using Of Recycled Rubber Tires And Steel Lathes Waste As Fibbers To Reinforcing Concrete

Hasan Jasim Mohammed; Abbas Hadi Abbas; Muhammed Abbas Husain

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 27-38
DOI: 10.37650/ijce.2013.80363

This research paper is accomplished to study the effect of using waste fibers in properties of concrete . Steel lathe waste fibers are added by percentages of (4, 6 and 8 %) from weight of concrete and a percentages of concrete coarse aggregate are replaced by rubber tires waste fibers in a ratios of (5, 10 and 15%) by volume . Besides to that, the combined fibers are used steel lathe waste fibers by adding (4, 6 and 8 %) with constant replacing of rubber tires waste fibers of (10 %). The results showed that adding of steel lathe waste fibers in plain concrete enhances its strength under compression about (15%) and tension about (20%), while rubber tires waste reduced both of compression about (80 %) and tension about (51%) strengths .Also the compression and tension strengths are reduced (88% and 30%) respectively with using combined fibers . The dry concrete density of lathe waste fibers concrete is (2345-2365kN/m3) , the rubberized concrete density is (2130-2240kN/m3) and for combined fibers concrete density (2025-2180 kN/m3).

Devise a mathematical model to represent the sediment at Al Anbar Thermal Power Station Outlet using GIS

Ahmed Amin Al Hity

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 37-56
DOI: 10.37650/ijce.2013.80538

This research aims to study sediment discharges in Al Anbar Thermal Power Station in two phases the first phases include a follow-up study sediment load from the river by taking samples at different depths and different discharges, and noted measurements, calculations for each section while the second phases included an account of the tonnage of river sediment through the program depends on the equation of Meyer, to five sections (18, 26, 35.43, 45) with the observation results and do a comparison between the two phases.

Research has included also employ technology of remote sensing and geographic information system GIS in the study of the waters of the Euphrates at thermal power plant after an analytical study was taken amount sediment and size in the study area and then link results with the geographic information system GIS for the purpose of producing layers represent the nature of the spatial distribution of these Sediments on the entire study area and the aerial imagery of software Google Earth with the use of the program (Arc view), one of the geographic information system software.
The research concluded give recommendations for controlling the movement of sediment when the at Al Anbar Thermal Power Station Outlet through two main axes of them increase the flow velocity exceeds the critical velocity and the other includes the disposal of sediments away from the site of the station outlet.

A comparison study between the manual and Computerized surveying systems in Engineering Surveying


Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 39-62
DOI: 10.37650/ijce.2013.80391

The present research aims at the comparison of the production time between the manual and computerized surveying systems. The surveying system consists of data acquisition, processing and plotting the engineering plan and contouring .The current computerised system is designed and tested using the pulse Total Station instrument GPT-2006, P.C. computer, traverse network adjustment computer programs, Auto Cad 2005, 2010 and Surfer- 9 contouring program.
The results of the current field experiments showed that the computerized surveying system offers a considerable savings in the data acquisition, processing and plotting times as compared with the manual surveying system, i.e. for traversing , the reduction in the production time is up to (84%), for plan ( up to 74%) and for contouring ( up to 84%). The practical applications of the current research are in the fields of civil engineering projects ( roads, buildings, etc.), irrigation and environmental engineering schemes.

Experimental Study of Thermal Conductivity for Different Types of Cement Paste in Iraqi Markets

Qais F. Hassan; Ehssan F. Abbass; Kammal J. Taufeek

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 57-68
DOI: 10.37650/ijce.2013.80535

In this study practical tests for thermal conductivity are done on twenty one specimens for seven types of cement mortar contains different types of cement available in local markets for Kirkuk city in the same standard conditions. Heat flow amounts within the specimens are calculated using Fourier law for conduction. Comparison between practical results and theoretical values depended in references for calculating thermal loads in concrete walls gave good agreement. Test results for specimen No. (7) for cement of Al-Sulaimanya company gave minimum value for thermal conductivity, which was (1.162 W/m.oC), and maximum value was for specimen No. (4) for Iranian cement, which was (1.55 W/m.oC) and for specimen No. (3) for cement of Bazian company, which was (1.52 W/m.oC). Results of thermal conductivity for all the other specimens were within the depended theoretical value. Minimum heat flow within the material was for specimen No. (7) for cement of Al-Sulaimanya company, while maximum value was for specimen No. (4) for Iranian cement.
Key words: thermal conductivity test, cement, mortar, heat flow, Fourier law for conduction.

Assessing the ability to implement ISCM for procurement in construction companies in Iraq (Al-Rasheed state contracting construction company as a case study)

Qais Kadhim Jahanger

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 63-78
DOI: 10.37650/ijce.2013.80365

Constructions industry by their projects and works is regard one of the biggest and important industries in most countries, which most of construction projects needing large amounts of materials, goods and services from different types. It can easily be seen that there is a consistently higher rate for the construction projects in Iraq when compared with the country's other industrial Activities. Integrated supply chain management for procurement processes from planning through good administration to contract closeout give best value from purchasing, storage and delivery just in right amount and time.
The objective of this research is to review the concept, definition, and benefits of ISCM for Procurement processes with assessing the implementation of such a procurement world class system for construction companies in Iraq through field survey and developing a "checklist" to investigate, record, weighting, and analyze the facts of existing procurement chain management of Al-Rasheed State contracting construction Company as case study. The research conclusions show that Al-Rasheed CO. implementation percentage of procurement management about 36.3%. where the management isn't aware of procurement management importance, so little knowledge about ISCM and its benefits for procurements processes to company and its projects, , therefore hasn't contrapuntal department for procurement . Several proper solutions were recommended to improve the existing supply chain management for procurement such as establishing procurement department, the role of leadership and commitment to procurement, documentation of ISCM, and proper database for vendors, materials, information and catalogs by modern Information's technology.

Two Dimensional Finite Element Model to Calculate the Influence of Channel Width Variation in Alluvial Channels on Bed Transport Capacity With Constant Value of Manning Coefficient

Uday Hateem Abdulhameed

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 69-84
DOI: 10.37650/ijce.2013.80592

The effect of change of channel width on bed load and transport load of sedimentation for given discharge are studied. The transport load is a mathematical function of change in channel width . The phenomena of transport load of sedimentation in a meandering alluvial channels are significant problems in river engineering and important factor that effects on the works of river control . The finite element model is developed to determine the effect of change of channel width on bed load capacity to ( 2.5 km ) length of the Euphrates river within hit city used value of manning roughness is ( 0.028 ). Calculated the optimum width actualized maximum transport capacity .

Improvement Of Traffic Capacity For Stadium Intersection In Al-Samawah City

Ahmed I. Ahmed; Abbas F. Jasim

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 79-100
DOI: 10.37650/ijce.2013.80366

Capacity and level of service are the control points of the analysis of intersections and must be fully considered to evaluate the overall operator of the intersection.
The objectives of the present study include the analysis, evaluation and improvement of the operation for Stadium Intersection in Samawah city and to present the best proposal to enhance the performance from the capacity point of view. To achieve these objectives, the estimated distribution of the traffic data in different directions that required for the traffic and geometrical analysis were gathered manually, while HCS traffic program is used for the requirements of traffic analysis process.
It has been concluded that the flyover between Al-Zwaid Street – Stadium Street (Proposal No.5) is the best proposal to improve the operation ability of Stadium Intersection.

Experimental investigation and FEA of AlMg3-stiffened rectangular plate subjected to concentrated load

Mohammed Midhat Hasan; Mazin Yaseen Abbood

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 101-109
DOI: 10.37650/ijce.2013.80392

In this paper, AlMg3-plates are studied through experimental and numerical using finite element representation under concentrated load at the center point. The plates of (300- × 200 mm) are clamped at the shorter ends and strengthened longitudinally by one rib at the centerline and two at different spans. the stiffened plates were modeled using a 3-D 10-node tetrahedral element with a non dimensional analysis. The models were validated using the results of tests on full-size stiffened plate specimens and were subsequently used to perform the study of the parameters presented in this paper. The parameters investigated are: the maximum stress, deflection of the plate and the position of ribs. Effect of the investigated parameters on the concentrated load strength were studied within elastic range. FEA give closer results with those of experimental and these results show that the use of two parallel ribs with a 40-mm span improves the strength of the plate. Due to these results, further investigation is presented to show the optimum thickness of the ribs at the best span.

Effect of Partial Replacement of Cement by Hydrated Cement on Properties of Cement Paste and Cement Mortar

Ali K. Ibrahim

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 110-119
DOI: 10.37650/ijce.2013.80393

This work study the effect of partial replacement of cement by hydrated cement on some properties of cement paste and cement mortar such as normal consistency, initial and final setting time, compressive strength, and length change. The results show that pastes containing hydrated cement require more water than reference paste to give normal consistency. The results also show that the replacement by hydrated cement delay the initial and final setting time of cement paste. The delay in setting time increased with increasing the partial replacement by hydrated cement.
Compressive strength test was carried out on (54) cubes of (50) mm side dimensions of mortars containing (5, 10, 15, 20, and 25%) of hydrated cement at (3, 7, and 28) days. They were then compared with reference mortar. The compressive strength results show that the compressive strength decreases with increasing the replacement percentage by hydrated cement at all ages. The decreases in compressive strength reached (23.05 %) when (25%) of cement was replaced by hydrated cement in (28) days.
The results also show that the replacement of cement by hydrated cement increases the length change of mortars compared with reference mortar.

Evaluating Traffic Operation for Multilane Highway (Ramadi – Fallujah) Highway as Case Study

Hamid A. Awad; Hameed A. Mohammed

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 120-134
DOI: 10.37650/ijce.2013.80394

Multilane highways typically are located in suburban communities, leading into central cities, or along high-volume rural corridors connecting two cities or significant activities that generate a substantial number of daily trips. The objectives of the present study include the analysis, and evaluation the level of service (LOS) on section for multilane highway in Ramadi city. The LOS multilane highway is based on density, which is calculated by dividing per lane flow by speed. The required traffic and geometrical data has been collected through field surveys on the section for multilane highway. Traffic volume data were collected manually and classified by vehicles types during each 15 minute interval. Highway Capacity Software 2000 (HCS 2000) program is used for the requirements of traffic analysis process to determine the level of service. It has concluded that the level of service on selected section for east bound is (A), and for west bound is (B).

Behaviour of Waste Plastic Fiber Concrete Slabs Under Low Velocity Impact

Abdulkader Ismail Al-Hadithi; Ahmed Tareq Al-Ejbari; Ghassan S. Jameel

Iraqi Journal of Civil Engineering, 2013, Volume 9, Issue 1, Pages 135-148
DOI: 10.37650/ijce.2013.80395

This research investigates the impact resistance of concrete slabs with different volume perecentage replacement ratios of waste plastic fibers (originaly made from soft drink bottles) as follows : 0.5%, 1% and 1.5%. Reference mix produced in order to compare the result. For the selected mixes, cubes with (100×100×100mm) were made to test compressive strength at age of (90) days. Flexural strength (Modulus of Rupture) test was also conducted using prisms sample of (500*100*100 mm) dimensions.
The low-velocity impact test was conducted by the method of repeated falling mass where 1400gm steel ball was used. The ball falling freely from height of 2400mm on concrete panels of (500×500×50 mm) having a mesh of waste plastic fiber.The number of blows that caused first crack and final crack (failure) were determined, according to the former obtained results , the total energy was calculated.
Results showed an improvement in mechanical properties for mixes containing plastic fibers compared with reference mix. For compressive strength the maximum increase in compressive strength was equal to (3.2%) at age of (90) days. Flexural strengths for mixes containing plastic fiber at ages 28, and 90 days are higher than that of these of reference mix. The maximum value of increaseing was (18%) for 28 days age of test and it was equal to (26%) for 90 days age of test for the mixture with plastic fiber content by volume equal to (1%) .
Results showed a significant improvement in low-velocity impact resistance of all mixes contining waste plastic fibers when comparing with reference mix. Results illustrated that mix with (1.5%) waste plastic fibers by volume give the higher impact resistance at failure than the others. The magnitude of an increase over reference mix was equal to (340%).