Al-Qadisiyah Journal for Engineering Sciences

Hydraulic properties of sandy clay soil are very important for filtration, seepage and irrigation; so set
of experiments were carried out for different samples of sandy clay in Baghdad. Measurements include
bulk density, particle size distribution, clay percentage and hydraulic conductivity using constant head
system. The aims of this study were to estimate equivalent saturated hydraulic conductivity (Ks) for
different clay percentages and predict porosity of sandy clay as function of clay percentage and
porosity of sand and clay. Nine samples of sandy clay soil have been tested in a hydraulic and soil
laboratory (Mustansiriya University). Semi-empirical model was correlated to evaluate saturated
hydraulic conductivity from clay percentage and results were compared with five empirical models
selected from published literature were also used to predict Ks. These empirical models were
(Puckett ,1985) , (Ryjov and Sudoplatov,1990), ( Dane ,1992), (Dheyaa ,2001)and (Shevnin.et al,
2006).

Horizontal Shear transfers through interfaces between two materials need to be studied accurately
especially when the interface separates two different materials. In this study the two materials are
concrete and bricks. This interaction can be formed in the regions where concrete is rested on brick
walls in so many positions in construction. The study focuses on an experimental work through a
series of push-off tests for ( concrete to bricks, cement mortar to bricks ) taking into consideration
that the shear connectors are steel bars. Throughout push–off tests and due to the applied horizontal
forces as slip had been attained. This forces and slips are recorded and graphically drawn. A
statistical regression was made to find the most representative formula of the mechanism of shear
transfer between concrete with bricks and between cement mortar with bricks. The predominant
factor in shear transfer between concrete and bricks is the amount of shear connectors because as
number of dowel bars increases the shear strength increases. The value of force recorded at 2mm
slip for concrete to concrete was around three to four times that for concrete to bricks in existence
of steel bars or steel dowels. This means that concrete to bricks is weaker than that between two
concretes

Landfill bioreactor is a modified technique comparing with the conventional landfill processes due to
its ability to reduce time for decomposition and enhancing the biogas generation. The basic goal of this
paper is to investigate the performance of a three lab-scale bioreactors under anaerobic conditions.
Three types of reactors differ in its internal composition were experimented ,bentonite clay was used as
a cover material. First reactor was filled with organic solid waste only; second reactor was filled with a
mixture of organic solid waste, Lime and sawdust, while the third reactor was filled with mixture of
solid waste and lime. Leachate characteristics traced includes pH, EC, TDS, TSS, Heavy metals (Cr,
Fe, Mn, Zn, and Mo), Sulfate SO-2
4 and Phosphate PO-3
4.
Experiments were conducted from October 2014 to march 2015, Results shows a significant variation
in removal efficiency for each reactor, heavy metals removal for the first reactor was (Mn 58.6%, Cr
13.4%, Mo 0%, Zn 27.2%, Fe 58.6%),and the second reactor removal efficiency was (Mn 77.2%, Cr
67.5%, Mo 69.19%, Zn 67.9%, Fe 56.7%), while for the third reactor was (Mn 30.1%, Cr 13.8%, Mo
18.48%, Zn 29.8%, Fe 70%). The results show that the solid waste, Lime and sawdust enhanced the
removal of heavy metals in the 2
nd reactor which gave best removal efficiency for heavy metals. While
the lime addition in the 3rd reactor increase the removal efficiency of iron to 70%. It can be conclude
that this modified landfill bioreactor enhance leachate characteristics and so enhancing the solid waste
stabilization

Artificial neural networks (ANN) were used to predict the viscosity of epoxy resin modified by
natural waste material (pomegranate peel) powder. This waste material, which has a high
pollution capacity for the environment, could be used as an improvement to the properties of a
weaken material such as epoxy resin In reservoir engineering computations the viscosity
parameter is a very important fluid property. The data is not either reliable or unavailable most of
the time; It should be specified in the lab. Levenberg-Marquardt backpropagation of artificial
neural network based model (ANNs) was evolved to predict the viscosity of modified pomegranate
peel powder of epoxy resin. Three parameters affecting the viscosity of mixtures based on epoxy
resin containing pomegranate peel powder and pure epoxy resin were studied. These are
temperature, concentration of pomegranate peel, and shear rate. The viscosity as output was
predicted by training the network. A network was built up and trained using experimental
information. The effects of temperature (30-50 °C), concentration of pomegranate peel powder (0-
6)wt% and shear rate (4.35-15.95 1/sec) on the epoxy resin were modeled by ANNs as well. The
expected values were in excellent agreement with the measured ones, showing that the developed
model is really accurate and has the great ability for predicting the viscosity. The linear regressions
R
2
0.9994 and 0. 9998 are the values of the ANN viscosity model for training and testing data set,
respectively, 2.7175*10-4
and 1.2441*10-4
are the values of mean square error respectively.

The surface to volume ratio of concrete pavement is large, also, due to hot climate of Iraq, coating
concrete pavement after casting is essential to ensure vital curing, consequently to obtain
significant engineering properties. This research work reports the results of a study performed to
evaluate the engineering properties of concrete coated with concrete surface coatings solutions; two
types of coating were used representing co-polymer (Styrene-Butadiene Rubber, SBR) and byproduct material (Residue Crude, RC). Different coating solutions were prepared from these
solutions, individually and collectively; i.e. 100% SBR, 75% SBR+25% RC, 50% SBR+50% RC,
25%SBR+ 75%RC, and 100%RC. The engineering properties of the uncoated and coated concrete
samples were evaluated by assessing compressive strength, flexure strength and hardness for
concrete convenience for highway rigid pavement. The compressive strength was evaluated for the
specimens at 7, 14, 28 and 90 days, where flexure and hardness were evaluated at 28days.
The results showed that the coated samples with both SBR and RC performed noticeably better in
contrast with uncoated samples under air-dry conditions. Additionally, obvious differences in the
performance of the collective solutions were recognized. From the results, however, local byproduct materials have been proven as a significant coating materials suitable to enhance the
concrete used for pavement purposes.

Modification or purification of potable water with the use of recycle waste glass reduces the drain on
the natural resources of the raw materials, which is widely used in our daily life. However, the disposal
of waste glass is not an easy matter, which is because glass is neither incinerated nor decomposed
material.
In this study, ten samples of potable water were collected from ten regions in Baghdad capital city in
order to investigate their physical and chemical properties. Chemical and physical properties of water
were identified. Several parameters of water quality were analyzed including: turbidity, electrical
conductivity, and acidity function (pH) and total suspended solids according to Iraqi standards.
The results of all water samples showed that the physical and chemical analysis tests were acceptable
for drinking except the station of Madinat Alsadar. Using the waste glass to eliminate this problem, as
low cost and inert material, was successful in potable water treatment. As a conclusion, the TSS was
decreased after filtration process by waste glass especially for Althaalba and Alameria potable water
which were disappeared (being zero)

The properties of groundwater in some wells digging on the border of Iraq with KSA along 400 km
from Al-Nekheab at west to Al-Salman at south of Iraq were evaluated. Eleven wells were chosen
as a case study depended on variable of water depth and stratum properties. Water samples were
taken at two periods the first one at summer and the other at winter reason. The chemical properties
of these samples were compared with the standard limits to evaluate the quality of water for
different uses. The main parameters used for evaluation process are negative and positive ions, total
dissolve salt, electrical conductivity, and turbidity.
Finally, conclude the usages of water of investigated wells were un-permitted for drinking
purposes except well No.10 unless treated by purifying process, but can be used for irrigation for
soil which has high permeability and good drainage in addition to plant have high strength for
salinity. In the other side all wells mostly used for livestock usages and poultry.
For industrial usages only well No.(10) can be used for industry of cement. While all wells can be
used for building purposes except wells No. (1, 2, 7, 11).

In this work, a numerical simulation of natural convection in an oblique enclosure filled with silverwater nanofluid is obtained for different values of Rayleigh numbers, volume fraction and
inclination angle of sloping walls. The considered oblique enclosure with left and right side walls
are maintained at constant cold temperature (Tc). The horizontal top wall of enclosure is kept
insulated, but the bottom is maintained at constant hot temperature (Th). The present work is
utilized to obtain results in the range of Rayleigh number (103
-106
) , volume fraction of nanofluid
varied from (0-0.2) and inclination angle of side walls are (-60o
, -30o
, 0o
, 30o
, 60o
). The Prandtle
number is 6.0. The governing equations in the two-dimensional are solved numerically by using
finite-difference technique.
Comparisons with other works are performed and the results are found to be in good agreement.
The obtained results are shown in the form of stream function, isothermal lines and average Nusselt
numbers. It observed from results that acute shaping wall and Ag-nanoparticles with high
concentration are effective to enhance the rate of heat transfer, also; the average Nusselt number for
all range of inclination angle increases with increase in the Rayleigh number and the solid volume
fraction of the Nanofluid.

Shear is transferred through interface between two concrete members by two mechanisms either by
aggregate interlock or by dowel action or by both in the same time. This media is very complex and
there are so many variables affecting shear transfer like surface shape and final treatment of the
concrete surfaces. Histories of the previous researchers are mentioned in this paper to find out the
applicable results of their equations. It is noticed that most of them depend on only clamping stress due
to dowel action while others used besides that the type of concrete used namely its compressive
strength. A mathematical statistical trials are made in this paper to find out the most accurate and
suitable equation which simulates the action happened in this media. An equation of six parameter
polynomial is obtained containing clamping stress and compressive strength of concrete. Assumed
values of the mentioned variables are used in this equation to find out the horizontal shear strength.
The deviation recorded is about 4% which is an acceptable one.

This paper presents an experimental study on the effect of transverse reinforcement on the axial
compressive strength of rectangular and circular cross sectional shape reinforced concrete (RC)
columns under axial compression. Twenty specimens of small scale RC columns specimens were
considered in the experimental tests. Ten of the columns specimens have a square cross sectional
shape with dimensions of (150×150) mm and the other ten specimens have a circular cross
sectional shape with a diameter of 150mm. For each cross sectional shape, the columns are
classified into two groups of five columns: the first group contains short columns according to
ACI-Code requirements (ACI318, 2011) and the other group consists of long columns. Each group
uses same longitudinal reinforcement ratio but with five different transverse reinforcement ratios
represented as a volumetric ratio of the transverse reinforcement. An experimental test has been
conducted to determine the maximum axial compressive load at which each concrete column would
fail. The experimental test results have shown that increasing of the volumetric ratio of the
transverse reinforcement leads to a considerable increase of the axial load resistance of the column
for both rectangular and circular columns and for both cases of long and short columns. The study
has also showed that using equations suggested by the ACI-Code to determine the axial
compressive strength of RC columns with tie reinforcement that are spaced at distances exceed that
suggested by the code, gives over- estimated predictions of the column axial resistance which may
results unsafe design.