Print ISSN: 1992-7428

Online ISSN: 2706-686X

Volume 12, Issue 2

Volume 12, Issue 2, Summer and Autumn 2018, Page 1-22


Mechanical Properties of Concrete incorporating natural Pozzolanic Material Subjected to Crude Oil

Shaho Mahmoud Hama

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 2, Pages 1-10
DOI: 10.37650/ijce.2018.162778

The paper shows the final findings of the effect of metakaolin on the strengths properties of concrete exposed to crude oil. Sulfate resistance Portland cement of V type was used and specimens of concrete were adjusted and subjected to a solution of concentrated crude oil. However, the samples are cured in a control media at immersion ages of (28, 56 & 120 days) with ambient temperature, then samples have been kept in curing water for comparisons purpose as well. The results explain that the use of metakaolin reinforces compressive, flexural and splitting resistance of concrete which is exposed to crude oil. The compressive strength reduction increased from 8.0% at (28 days) to 37.7% at (120 days) curing for normal weight concrete (NW) whereas the concrete incorporating metakaolin (MC) has a reduction of 6.0% at (28 days) & 29.3% at (120 days). .

Study on Flexural Behaviour and Cracking of Ferrocement Slabs by Neglecting Very Fine Sand

Mohammed T. Nawar

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 2, Pages 11-22
DOI: 10.37650/ijce.2018.162779

This paper presents the experimental results of eight slabs made of Ferrocement. All specimens were )700mm (long, )300mm (wide and )50mm (thick. These specimens were divided into two groups (The first group has four specimens coursed of normal sand gradient and in the other four specimens, the sand that passing from sieve No. 8 was neglected), to investigate behavior of slabs under bending effect and studying the cracks that generated after bending then, comparing the results between these two groups. A thin square welded wire mesh was used as reinforcement. The number of wire mesh layers was varied between 0 to 3 layers. Ultrasonic Pulse Velocity (UPV) Test was used to detect the cracks. The results showed that there was a slight rise in bending for first group slabs compared with second group slabs. Maximum bending strength was achieved for both slab groups with 3 layers of wire mesh. it was shown that there was a significant convergence in the load values required to cause appearing of the first crack and final failure for the two groups. The percentage of ultimate load between slab reinforced with 3 layers and without reinforcement was (25.27%) for the first group, while the increase in ultimate load for a specimen that reinforced with 3 layers was (24.16%) compared to specimen without reinforcement for the same group. On the other hand, the results showed an improvement in the performance of the second group slabs due to its resistance to appearing of cracks resulted from bending. The percentage of increasing cracks after bending for the unreinforced specimen in group 1 was (9%) compared with the unreinforced slab in group 2. Whereas the numbers of cracks number in slab reinforced with 1 and 2 layers in the second group were less than slabs with 1 and 2 layers in the first group about (8.86 %) and (7.77%), respectively. While this percentage for a specimen with 3 layers in group 2 was about (8.62%) less compared to the specimen with 3 layers in group 1..

Prediction variation in asphalt pavement temperature during summer season in Ramadi city, Anbar Province, Iraq.

Khalid Awadh .

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 2, Pages 23-29
DOI: 10.37650/ijce.2018.172880

Asphalt pavement temperatures were estimated at surface and depth of 50 mm. Differences between estimated maximum surface temperatures and maximum air temperatures were found to be remarkably high, whereas the minimum surface temperatures were slightly different from minimum air temperatures. Different studies showed that the maximum pavement temperatures at depth (50 mm) were less than that of the maximum surface temperatures, whereas, minimum pavement temperature at the same depth showed slightly higher readings than that of the minimum surface temperatures.Algorithms that discussed in this research work found to produce remarkably different estimations of depth temperatures. The undergoing research work aims to cast light on the performance of these models in terms of data regarding Anbar province of Iraq.
 

 

The possibility of using Polyethylene terephthalate (PET) as a fibre to improve the ductile behaviour of concrete

Hamid Hamood Hussein .; Osama Abd Al-Ameer .; . Mahmoud Khaled Ahmed

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 2, Pages 30-39
DOI: 10.37650/ijce.2018.172881

To preserve the natural materials, applying the principles of sustainable engineering, to approach the principle of zero waste and to contribute the solution of the negative environmental impact of two decades, which is caused by excessive use of bottles of polyethylene terephthalate (PET) in packaging, has led to the approach of alternative, clean and innovative technologies aimed at recycling and reuse to address this environmental problem. Proposed re-use empty bottles as a way to get rid of them and benefit from them at the same time the way, this method through which the empty bottles cutting into fibres using these fibres made of PET to improve the properties of concrete. Percentage of fiber that has been used are 1%, 1.5%, 2%, 3%, 4%, and 5%. Suitable tests were performed to measure properties of concrete reinforcement by recycle PET fibre such as compressive strength, splitting tensile strength, four-point bending strength, modulus of elasticity and toughness index. Flexural toughness tests were performed to measure the ductility capacities of reinforced concrete members with recycled PET fibre reinforced concrete. The results obtained indicate Toughness index was enhanced by using PET fibre reinforced concrete specimens, compared to no ductility performance of concrete specimens without fibre reinforcement. A significant change in ductility was when observed PET used fibre with 3%.
 

 

Modification of Soil Used in Core of Earth Dams

Hassan A. Omran .; Noura B. Ibraheem .

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 2, Pages 40-46
DOI: 10.37650/ijce.2018.172882

The earth-fill dams are simple structures which are able to prevent the sliding and overturning because of their self-weight. Due to lack of suitable clay materials, the dams may be designed as zoned core which is composed of three vertical zones contains central impermeable core and two permeable shells on their two sides of the core. Impervious core is used in zoned earth dam to reduce the quantity of seepage through the body of the dam and to relief part of risk of piping and erosion in the downstream side. This study aims to study the soil properties that is used as a core of earth dam through a series of laboratory experiments that were carried out a several soil samples mixed with both lime and silica fume, in order to stabilize the soil. The process of stabilization aims to increase the soil strength and reducing its permeability and compressibility. Test results show that adding lime and silica fume to the soil decreases the permeability of soil with different cases of study, the percentage of decreases in case of standard compaction about (21%-90%) while in modified compaction test the permeability decreases in range (41.7%-91.3%). Also the unconfined compressive strength of the soil increasing significantly in both cases of compaction which were standard and modified. When add the materials, these values were increased in range (76%-90%) for samples from standard compaction test, while it being (0.21%-42%) in modified compaction test.
 

 

Finite element Analysis of Large Span Continuous Two-Way Ribbed Slabs with Some Parametric Studies

Ayad Abdulhameed Sulaibi .; Dhifaf Natiq H. Al-Amiery .

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 2, Pages 47-68
DOI: 10.37650/ijce.2018.172883

This paper investigates the results of finite element analysis for three proposed full-scale two-way slabs. The aim of this study is to use finite element method (FEM) by using ANSYS-v15 program to analyze the proposed slabs and study the flexural behavior , especially load-deflection relationship and ultimate strength. Some parametric studies on these works are also done to cover the effect of some important parameters on the ultimate load capacity and deflection. Proposed slabs are divided into three groups with different dimensions to study the effect of using continuous large spans on the structural behavior of two-way ribbed (waffle) slabs as compared to solid slabs. In all three groups, each slab consists of three by three panels supported by concrete columns at corners. For the first group, when the void ratio (the ratio of volume of voids between ribs to total volume of ribbed slab) increases, the stiffness of waffle slab also increases. Increasing stiffness for waffle slab is continued up to some limit, and then will decrease with increasing void ratio. The best case in this example occurs when the void ratio equal to (0.667) which gives increase in stiffness of (0.347) as compared to solid slab with the same thickness. The results of ANSYS analysis shows that the best percentage of increase in deflection is (51%) with decreasing in concrete volume of (59%) for long to short span ratio of (1.5) and (300)mm thickness. For the third group of proposed models, the stiffness of two-way ribbed (waffle) slab is higher than the solid slab which has the same volume of concrete. The displacement of two-way ribbed (waffle) slab in the elastic range (at first crack ) is lower than the solid slab. In this manner, it will give the maximum reduction in concrete weight with higher thickness.
 

 

Effect of Clay Bricks Powder on the Fresh and Hardened Properties of Self-Compacting Concrete

Oday A. Abdulrazzaq .

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 2, Pages 78-89
DOI: 10.37650/ijce.2018.172885

Fresh and hardened properties of self-compacting concrete was experimentally examined by replacing different percentages of cement by soft clay powder, which resulting from crushing the wastes of clay bricks. Three percentages (5%, 10%, and 15%) of cement were replaced with clay powder to study their effect on the properties of cement mortar and concrete of Grade (C35) in both fresh and hardened states. It was found that development rates of the compressive and tensile strengths for the mortar between ages of 7 to 28 days, decreased with increasing the percentage of the clay powder. Compared to the mix without clay powder, it was found that replacing (5%) from the cement causes a significant increase in the workability of the self-compacting concrete and the properties of the resulting hardened concrete such as compressive strength, tensile strength, and modulus of elasticity. While using (10%) and (15%) of the clay powder causes a significant decrease in the workability of the fresh concrete and the properties of the hardened concrete compared to mix without clay powder.
 

 

Finite Element Analysis of Normal Strength, High Strength and Hybrid Reinforced Concrete Beams

Nura Jasim Muhammed .; Shaimaa T. Sakin .; Dunia sahib .

Iraqi Journal of Civil Engineering, 2018, Volume 12, Issue 2, Pages 90-193
DOI: 10.37650/ijce.2018.172886

This paper presents the numerical study to simulate the flexural behavior of normal strength, high strength and hybrid reinforced concrete beams, under two points load with two different reinforcement ratio. The hybrid beam consists of two layers: the compressive layer is made of high strength concrete, and the tension layer is made of normal strength concrete. The simulation was done with a finite element model using the commercial finite element code, ANSYS (v.9.0). The concrete component material is modeled, the internal steel reinforcement modeled using ''LINK'' elements. The modeled behavior shown a good agreement with the experimental data. The maximum percentage difference in ultimate load-carrying capacity is 8% at the ultimate load level.Analytical study also included the effect of increasing the depth of the normal strength concrete for the hybrid reinforced concrete beam and the effect of increasing the compressive strength for high strength concrete and normal strength concrete respectively on the behavior and the load carrying capacity of the hybrid reinforced concrete beams.