Print ISSN: 1992-7428

Online ISSN: 2706-686X

Volume 12, Issue 1

Volume 12, Issue 1, Winter and Spring 2018, Page 1-124


The Effect of Using Lightweight Aggregate on Some Properties of Cement Mortar

Ziyad Majeed Abed

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 1, Pages 1-9
DOI: 10.37650/ijce.2018.142403

The aim of this research is to produce lightweight cement mortar with properties better than reference ordinary cement mortar. Porcelanite stone were utilized as lightweight aggregate with a volumetric partial substitution of fine aggregate. The process includes using different percentages (5, 10, 15 and 20 %) of pre-wetted (24hr.) porcelanite to produce lightweight mortar with internal curing. Water curing was used for reference mortar mixture and air curing for the other mixtures of porcelanite substitution. Compressive strength, flexural strength, density and ultrasonic pulse velocity for different ages (7, 14 and 28 days) have been tested. The results show an improvement in the properties of cement mortar especially in replacement percentage of 10 %.

Ductility and Toughness of Unsymmetrical CFRP Strengthening of Reinforced Concrete Beams

Abdulsalam M. Njeman; Akram S. Mahmoud

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 1, Pages 10-25
DOI: 10.37650/ijce.2018.142404

The use of externally bonded composite materials such as carbon fiber reinforced polymers (CFRP) sheets is a modern and convenient way for strengthening and repairing reinforced concrete (RC) beams. This study presents experimental investigations on the flexural behavior of reinforced concrete beams strengthened by unsymmetrical CFRP sheets with various configurations. Effects of number of which strengthened faces of strengthening and fiber direction on the flexural strength of RC beams are examined. Six RC beams with dimensions of 100 mm * 220 mm were casted and tested under two points loading. One beam considered as a reference (unstrengthened) beam. Five residual beams were strengthened using CFRP sheets with various configurations. From the results, it was observed that all strengthened beams showed higher ultimate load capacity than that of the control beam. On the other hand, it was found that a progressive reduction in flexural ductility and toughness of beams with strengthening in one face and two faces with horizontal fiber direction. The highest decrease in flexural ductility and toughness for strengthened beams with horizontal fiber direction in comparison to control beam were 63% and 54%, respectively. On the contrary, the flexural ductility and toughness of strengthened beams increased with strengthening by vertical fiber direction. Additionally, the maximum percentage of increase in flexural ductility and toughness were 41% and 54%, respectively in comparison with control beam.

Development length of Tension Bars in Concrete Beams- Revisited

Dhiyaa hamoodi Mohammed

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 1, Pages 26-34
DOI: 10.37650/ijce.2018.142405

Presently development length of tension bars in reinforced concrete beams, in both codes and researches has a very wide range on the influence of major parameters. Namely, the influence of concrete compressive strength f́c affects the development length of beams by varying power values: 1/2, and 1/3. It is well known that the development length of beams is essentially based on empirical or semi empirical formulae. A total of 254 NSC and HSC tested beams available from the literature are studied in this work. These includes 154 beams without transverse reinforcement and 100 with transverse reinforcement and having a different compressive strength ranged from (16.4 – 98) MPa. The best available design method obtained from the literature leads to 43.31% increase in the coefficients of variation COV compared to the proposed design method in this work, which is essentially whose COV of 14.06%.

Biodegradation of organic content via activated sludge seeding coupled with aeration in simulated self-purification sewer system

Kareem Kh. Al-Jumaili; Riyadh H. Al-Anbari; Tala A. Al-khateeb

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 1, Pages 35-44
DOI: 10.37650/ijce.2018.142406

Partial degradation of organic materials presented in sewage water had been conducted in the current research in a simulated sewer system. The process had been improved by aeration and seeding with activated sludge to reveal the effect of increasing the amount of biomass in the system. Three ambient temperatures were conducted as 10, 20, and 30 OC to display the influence of temperature on the degradation process. The results revealed that adding activated sludge to the system in a ratio of 50/50 (v/v) had a significant influence on the degradation as more microorganisms required more organic nutrients. In the other hand, increasing the operating temperature indicated positive influence in terms of soluble chemical oxygen demand (SCOD) removal as temperature motivated the living biomass towards severe degradation.

Producing of eco-friendly lightweight concrete using waste polystyrene particles as aggregates with adding waste plastic

Saad J. Mohammed; Abdulkader I. Al-Hadithi; Shamil K. Ahmed

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 1, Pages 45-56
DOI: 10.37650/ijce.2018.142407

This research includes studying the possibility of producing a new kind of No-fines concrete by replacing granules of coarse aggregates with grains results from the fragmentation of industrial waste of polystyrene. This replacing were with different volumetric proportions of coarse aggregate, and theses volumetric ratios were equal to (5%, 10%, 15% and 25%). Waste plastic fibers (WPFs) resulting from cutting of soft drinks bottles were added for strengthening this new kind of concrete. Mixing ratio was equal to (1:5) (cement: coarse aggregate) by weight. One reference mix was produced for comparative purpose. Compressive strength, flexural strength and density tests were conducted, it was examined three samples of each examination and taking the average.
Compressive strength values of the new sustainable concrete were ranged from 10 MPa to 12.4 MPa at age of test equal to 28 days, while the average value of the density of this concrete at the same age reaches 1930 kg/m3. This average value of modulus of rupture was equal to 2.36 MPa at 28-day age test.

Utilization of Municipal Solid Waste Ash in Concrete by partial Replacement of Cement

Faaeza Ahmed Abd Ul-Kareem

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 1, Pages 57-66
DOI: 10.37650/ijce.2018.142408

The problem of solid waste is being emerged increasingly due to the increased quantity of solid waste as a result of population’s increase .From the point of view of environmental and energy concerns, it is preferable to reuse the organic and inorganic components of solid waste in order to minimize the cost. In this investigation, the possibility of using solid waste ash (SWA) as a partial replacement of cement and its effect on the mechanical properties of concrete was studied. Samples of municipal solid wastes were collected were burring and changed to ash. A total of 50 cubes, 15 small cubes, and 30 cylinders, as well as 5 prisms were prepared .Various properties of solid waste ash are added to the cement mistures with percent's of 5, 10, 15 and 20 percent by weight of solid waste ash. A concrete mix with a percent solid waste ash was used as reference. Pozzolanic activities of all mortars, and setting times of all pastes, and workability of all mixes were investigated .Compressive strength, splitting tensile strength, absorption, and drying shrinkage for reference for reference and solid waste concrete specimens were investigated at various ages. Results demonstrate that the pozzolanic activity was within ASTM requirements for the cases of 5% and 10% ash replacement. For 15 and 20 percent replacement this activity was only slightly less than the ASTM value.
The 90-day compressive strength rose, in comparison with control specimens, with 5 percent replacement and was only slightly lower at 10 percent replacement. In splitting tensile strength was at least equal to reference specimens for all replacement ratios. The rise in these values, over the reference specimens, ranged between 0 to 21 percent for the case of 20 and 5 percent replacement, respectively.

Construction and Operation of Two Chamber Fuel Cell under Synthetic and Real Wastewater with Different Operation Conditions

Afaf Jadaan obeid

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 1, Pages 67-74
DOI: 10.37650/ijce.2018.142409

Constructing and testing a microbial fuel cell, (MFC) was accomplished in this research. Two chambers MFC connected with salt bridge was operated and studied using synthetic and real wastewater as anode chamber solution. Operating temperature and pH value were investigated by changing temperature from 25 OC to 30 OC and varying pH from 6.7 to 6.5. The results reveled that increasing operation temperature had a significant effect on reducing operation time while decreasing pH improved the measured voltage and current besides reducing operation time to just five days. The cell was tested with the presence of real wastewater under the optimal temperature and pH and the results proved the capability of the manufactured cell in treating such contaminate in relatively short operation time. The COD reduction rate was above 60% indicated the ability of living microorganisms in digesting the wastewater producing electrical power with maximum values of 0.443 mV and 8.3 μ A for voltage and current, respectively.

Experimental Behavior of High Strength Concrete Filled Double Skin Steel Tubular Columns

Samoel Mahdi Saleh; Fareed Hameed Majeed

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 1, Pages 75-85
DOI: 10.37650/ijce.2018.142410

A series of experimental tests were carried out to investigate the behavior of high strength concrete filled double skin steel tubular (HSCFDST) columns. Fourteen column specimens were tested in the present study, taking into account the effects of the shape of column cross section (circular or square), the hollowness ratio, and the slenderness ratio. For comparison, two of the tested specimens were filled with normal strength concrete. It was seen that the ultimate axial strength of the square HSCFDST columns is greater than that for circular ones, in spite of that the sectional properties were approximately equal. Also, it was found that for both circular and square column specimens, the ultimate axial strength of HSCFDST columns was inversely proportional to their hollowness and slenderness ratios. CFDST column specimens filled with high strength concrete compared with those filled with normal strength concrete increased stiffness and ultimate axial strength, but give unexpected results for the ultimate axial strength, therefore the suitable choice for the section properties of the inner steel tube is required. The experimental results and analytical approach that developed by other researchers shown good agreement.

Suitability of Surface Water for Drinking purposes in Basrah City Using Water Quality Index (WQI)

Ayman Alak Hassan

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 1, Pages 86-95
DOI: 10.37650/ijce.2018.142411

The water quality index (WQI) is applying for the integrating the water quality variables into a single number to indicate the overall quality of water. Rivers is one of the essential water resources, the protecting and preserving for the quality of this resource is important and imperative. An evaluation of water characteristics of the Shatt Al Arab River in Basrah city was performed in order to determine the quality of water for drinking usage. In this research, monitoring of variation in the characteristics of water was accomplished by collecting monthly water samples for three years. The water samples from the Shatt Al Arab River is analyzed for eight Physical and chemical parameters such as pH, total dissolved solids (TDS), electrical conductivity (EC), total hardness (TH), calcium (Ca), magnesium (Mg), sulphate (SO4) and chloride (Cl) using standard methods. Utilizing the WQI discovered that the water quality of the studied river is ranked between very poor water type and not suitable water for drinking usage category. In the present investigation, the quality of water was revealed that the average of WQI value for the studied years was 318, 337.3 and 456.7, respectively.

Impact Strength for the 3D Textiles Fiber Reinforced Cementitious Composites Plates

Waleed A. Abbas; Ikbal N. Gorgis; Nadia Moneem

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 1, Pages 96-109
DOI: 10.37650/ijce.2018.142412

The use of textile reinforcement made from non-corrosive materials, such as carbon and glass can reduce the required concrete material; this is known as Textile Reinforced Concrete (TRC). This study deals with plate specimens having dimension of 500×500×40mm tested under impact load at 28 and 90 days age under two conditions of ends, simply supported and fixed. Cement mortar with about 60 MPa, 7cm cube compressive strength at 28 days was designed for casting the plates. Plate specimens were divided into four groups, they consist of reference plates (no reinforcement) and plates reinforced with 3D glass fabric having three different thicknesses 6, 10 and 15mm.
The results indicate that using 3D textile glass fabric cause an increase in number of blows, reduce in final stage deflection, an improvement in toughness and energy absorption under impact loads. Using 3D textile glass fiber with 10mm thickness gave higher number of blows for 28 and 90 days as compared with 6 and 15 mm. Plates with slice 6mm 3D textile glass fiber in two way reinforced has significantly enhancement in number of blows, the improvement was about (80 - 125%) and (128.5- 114. 3%) for 28 and 90 days respectively. The specimens showed increase in the energy absorption, besides the number and width of cracks was reduced and only few cracks are propagated up to the edge of the plates.

The Effects of adding Waste Plastic Fibers on the Mechanical Properties and Shear Strength of Reinforced Concrete Beams

Abdulkader Ismail Al- Hadithi; Mustafa Ahmed Abbas

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 1, Pages 110-124
DOI: 10.37650/ijce.2018.142480

The concept of sustainability was developed in the last years and included the construction industry to solve the issues that pertaining by high consumption of natural sources, environmental pollution and high amount production of solid wastes. On the other hand, the plastics generation is growing exponentially every year, especially, types of Polyethylene Terephthalate (PET) that are used to produce soft drinks bottles, this study attempts to apply the concept of sustainability and reduce the environmental pollution by cutting the plastic bottles (PET) as small fibers added to the ordinary concrete to improve the shear and tensile strength of reinforced concrete beams. For this purpose, the experimental work was carried out to study the effect of waste plastic fibers (PET) on the shear behavior of seven reinforced concrete beams with dimensions of (100×150×1200) mm that were designed to fail in shear, the fibers percentages that were used in this study are (0.25, 0.5, 0.75, 1, 1.25 and 1.5%). Also, the influence of Polyethylene Terephthalate (PET) fibers on the mechanical properties of concrete was studied such as: workability, compressive strength, splitting tensile strength, static modulus of elasticity and ultrasonic pulse velocity.