Engineering and Technology Journal

Since asphalt binder is the most important factor that affects low-temperature
cracking. It is imperative to know the critical cracking temperature in order to identify
susceptible asphalts. The low temperature thermal cracking of asphalt pavements is one of
the main causes for annually repeating expensive highway repairs. To determine the lowtemperature
cracking potential of the asphalt binder, asphalt binder cracking device
(ABCD) was used. The operating principle of ABCD is based on the differential thermal
contraction between the metal ABCD ring and an asphalt binder placed outside the ring,
as the temperature is lowered, the test binder shrinks more rapidly than the ABCD ring
placed inside, which lead to develop thermal stresses, when the thermal stress exceeds the
strength of the binder, the binder specimen cracks. Strain gauges installed inside the ABCD
ring detect the fracture, and the temperature is recorded as the ABCD cracking
temperature. Four groups of local asphalt binders were used for this study; Daurah PG
64-16 (Pen 40-50) both rolling thin film oven (RTFO) and pressure aging vessel (PAV)
aged , Daurah PG 58-22 (pen 85-100) RTFO and PAV aged, Baiji PG 64-16 (pen 40-
50) RTFO and PAV aged, Basrah PG 64-16 (pen 40-50) RTFO and PAV aged. There
is a fairly good agreement between ABCD results and Bending Beam Rheometer
(BBR) in cracking temperature, for asphalt binder PG 64-16 the differences in
cracking temperature about 6 o C, while for asphalt binder PG 58-22 there no
significant differences. All the tests of local asphalt binders are done in the University
of Wisconsin-Madison- USA

Some studies suggested a model to determine the grain size distribution GSD curve
of the self-filtration layer that is formed at the base soil-filter interface. From these
GSD curves the effectiveness of the filters is assessed assuming that the internal
stability of the self-filtration layer reflects the effectiveness of the filter. In this paper a
critical discussion to that method is presented. Also some essential modifications for
the method are suggested. Finally, in disagreement with that method the applicability
of usage of the GSD curve of the self-filtration layer to predict the effectiveness of the
filter is found to be unreliable

Emulsified asphalt mixture is generally a mix made of emulsified asphalt with
aggregate. Emulsified asphalt is manufactured from base asphalt, emulsifier agent
and water. This study aims to study and improve the emulsified asphalt mixtures with
using of ordinary Portland cement as filler materials for road construction and
maintenance in Iraq as an alternative to the hot asphalt mixtures, due to its
economical, practical and environmental advantages. Beside this study focused to test
and evaluates the emulsified asphalt material properties to be used as paving mixture.
The tested properties of emulsified asphalt mixture were bulk density, air voids, dry
Marshall Stability, wet Marshall Stability, retained Marshall Stability, flow tests with
different compaction efforts differ from standard Marshall Limitations and compared
with the common used specification. The results indicate that the emulsified asphalt
type cationic slow setting low viscosity (CSS-1) is very suitable with quartz type of
aggregate from Al-Nibaay quarry. From many trial mixes it is found that the best
percentages of initial residual bitumen content to produced adequate results for
coating test ,mixing ,compaction ,curing and Marshall stability were ranged from
(2.5%, 3%,3.5%,4% and 4.5%), and the optimum percentage is (3.5%).Finally it can
be conducted that the emulsified asphalt mixture contained Portland cement filler
material is a suitable alternative mixture to the hot asphalt mixture for road
construction and specially maintenance of roadways in Iraq

This paper presents a status report on evaluation of the asphalt pavement using
the ground penetration radar device (GPR) in one of the University of Technology
streets about 92 m length. The technique of GPR is a nondestructive geophysical
method that gives information about the thickness of asphalt pavement layers,
existence of drainage pipes, rutting places and produces a continuous crosssectional
profile or record of subsurface features without drilling, probing, or
digging.
Three samples of asphalt were taken from different places of the street. The
thickness of asphalt layers were measured from these samples. One of the samples
consists of two layers and the others of one layer.
Comparison of the two results of the thickness from the device and the sample
indicate that there was very slight difference between them

The purpose of this study is to evaluate the effect of hydrated lime addition methods
as filler replacement on fatigue performance of Hot Mix Asphalt (HMA). Three types of
addition methods of hydrated lime were introduced namely dry HL on dry aggregate and
saturated surface aggregate above 3% and slurry HL on dry aggregate, ordinary Lime
stone powder was reduced by three HL percentage (1.0, 2.0 and 3.0 %). The effect of
different methods were investigated on the fatigue properties of HMA using, third-point
flexural fatigue bending Test. Pneumatic Repeated Load System (PRLS) was carried out
to establish the effect of hydrated lime on the fatigue failure criteria and to select the
proper hydrated lime application methods on fatigue behavior of HMA mixtures. The
fatigue functions for asphalt mixture with hydrated lime are obtained and compared, and
it confirm that the fatigue property of asphalt mixture can be improved using all methods
and the addition methods were exhibited different optimality for the result due to its
effect . The test results were carried out through the performance analysis using Vesys
5W (2003) to study the long term effectiveness of hydrated lime effect

Natural disasters/armed conflicts can cause major damage to road networks of the
affected area. This can lead to significant impact not only on the road networks. The
major challenge in the aftermath of such events is to ensure a speedy
recovery/rehabilitation of roads and transportation networks so that regeneration can
commence in an effective manner. Prioritizing regeneration of the road network may
need context of a range of requirements including health, education, security, and
economic amongst many that will also require addressing. This study has been conducted
to give a better understanding of major factors that govern road recovery prioritization
across the affected region in Iraq. These factors need to be used in an effective and
efficient manner that can help in determining the road recovery priority.
Interviews and a questionnaire survey are conducted with experts in road reconstruction
and maintenance organisations to investigate the impact of the important proposed
affecting factors that can be critical for determining the recovery priority of damaged
roads. Five estimated groups of factors have been included in this study, which are:
socio-economic, road network, traffic, damage and financial factors. Each group also
consists of a number of estimated sub-group factors. As a result, twenty nine factors have
been chosen in this study.
It has been found from the results of the interviews and questionnaire that the proposed
factors and factor groups are with a level of importance of high and very high. This
indicates that the groups and factors included in this study are important for the
successful building and implementation of the process and procedures of the road
recovery priority in the road rehabilitation projects.
Each estimated factor within each proposed group used in this study contributes a
different weight value to the overall road recovery priority. According to the
questionnaire’s results, the most important factors are: number of critical socio-economic
facilities, type of road, delay time, severity of damage and effect on the economic.
Moreover, a different weight has been contributed by each estimated

Permanent deformation in asphalt layers which manifestation on pavement
surface is named rutting which represents one of the most significant distress of
asphalt pavements. Different empirical models have been used to calculate
permanent deformations which include traffic conditions and temperature effect.
These empirical models were calibrated in a three dimensional finite element
commercial software package. Finite element analysis through ANSYS computer
software (version 11.0) was used to analyze three dimensional pavement structures
and in order to investigate the impact of wheel load on rutting formation and
pavement response considering temperature effect. In that model, the asphalt layer
was assumed to follow a viscoelastic behavior by depending on dynamic modulus
using Timm and Newcomb model. While, granular and subgrade layers were
presented as linear-elastic perfectly plastic based on Drucker-Prager model. After
insuring the model validation, the study investigated the effect of temperature on
the rutting depth and plastic strain as a pavement response. The analysis of results
showed that the rut depth and plastic strain increases with increasing the
temperature

Demolished concrete structures proven to be a good source of construction materials.
This paper studies the utility of using recycled construction rubbles to improve some
properties of compacted subbase .Different subbase materials were produced with 0%,
25%, 50%, 75% of recycled construction rubbles aggregate as a partial replacement of
natural subbase. The standard tests were conducted on the choosed maerials before and
after the replacement. It is found from the test results that the recycled construction
rubbles can be used significantly to improve the properties of some types of subbase.
The CBR values of the subbase materials prepared with crushed concrete, recycled
bricks, and ceramic rubbles as a partial replacement were better than those of natural
subbase materials. The performance of subbase containing crushed concrete rubbles
was better than the performance of subbase containing crushed clay bricks and
ceramics. The CBR values for all subbases

The main aim of this study was to evaluate the asphalt mixture properties for
samples that were taken from different sites and plants: Amanat Baghdad, Faluja
municipality, and Baghdad Governorate, which almost produced in private plants.
Forty seven asphalt mixtures samples were tested following Marshall Test. The tested
properties were: Marshall Stability, Marshall Flow, specimen density, and air voids.
Asphalt extraction was carried out according to quantative extraction of bitumen from
paving mixtures test.
A statistical analysis of the collected field data was performed and a prediction
model was built. The variables such as asphalt content, stability and flow data were
analyzed using computer software. The statistical analysis includes four stages: data
extraction and evaluation, verification, calibration, and validation.
Results of this study indicate that both of Marshall Stability and Marshall Flow
correlate positively with asphalt content, but with different degree. Asphalt content
affect Stability property much more than flow property of the asphalt

The aims are to study the effect of dust storms and sand on traffic safety in Iraq
in general and in Salahuddin province in particular, especially as the dust storms
have become a threat to road users (people and vehicles) and result in direct
impacts and multiple life and human health and the conditions of social and
psychological generally through its impact on the surrounding environment and the
traffic of vehicles. Types of dust storms sweeping the region and examined models
of them to find out what the quality and measure wind speed caused by the use of
statements meteorological previous years has been studied and the work of a
questionnaire distributed to drivers of vehicles to demonstrate the impact of these
storms on them and the work program of statistical analysis, the results showed that
storms pose a threat heavily on traffic safety, but local storms more dangerous than
storms overall public because they suddenly appear and disappear in less than an
hour and there are no signs or warning to occur and surprised the driver or
pedestrian and cause confusion and traffic accidents. Recommendations of which
was given the green belts around cities, landscaping and paving

The signalized intersections are considering one of the critical elements in facility work of
urban arterial roads. Thus, it is necessary to improve the signalized intersections system not
only to increase the ability of flow on the major and minor roads but also to increase the
neighboring freeways ability to work with high efficiency.
In the 4-leg signalized intersections, left-turn effect greatly on the capacity, if left-turn
movements eliminated by converting it to right and through, so that, the signal can operate with
only two phases instead of four phases and capacity will increase. The objective of this study
was to evaluate the influence of eliminating left-turn movements (converting it to through and
right movements) on the level of service for an intersection of freeway off-ramps with arterial
roadway (figure. 1), in order to decrease the congestion on the oversaturated off-ramps, which
affect the traffic flowon freeway.Also studying the influence of this elimination and converting
on: (1) average system delay, (2) fuel consumption, (3) average travel time, (4) average delay
on freeway off-ramps and (5) average queues lengths on freeway. This elimination and
converting will be carried out by constructing two roundabouts (nearby to the intersection) on
arterial roadway Figures. (5 &6). Full-movement signalized intersection with two roundabouts
were compared before and after elimination left-turn movements through simulation with the
use of the Synchro 6 simulation package. The results showed a significant improvement in level
of service for the studied intersection. In addition, significant decrease in average delay and
average travel time, and minor decrease in fuel consumption. The results also showed a
significant decrease in average delay on freeway off-ramps and queues lengths on

Drivers in Iraq tend to disregard lane markings and use every available meter
of signalized intersections approach width. Thus, actual vehicles queues usually
exceed marked lanes. This paper analyzes the effect of this behavior on signalized
intersection capacity by estimating the passenger car equivalent (PCE) for
different types of vehicles under these prevailing conditions. Multiple linear
regression analysis was employed by considering all the through lanes in the
approach as the unit of analysis; the necessary data were collected from a
congested signalized intersection within Al-Hilla Province by using videotaping
and for a period of four days (8 hours per day). The study resulted in some useful
findings for signalized intersections capacity analysis. The saturation flow rate
was estimated to be 1818 passenger cars per hour of green per marked lane. The
results revealed that the minibus (e.g., 25-seat Toyota Coaster) and the passenger
car time headways were equal, and thus have the same effect on intersection
capacity. It is believed that this is due to the observed reckless driving of minibus
drivers.

Operation and maintenance problems of highways network in Iraq are going
continuously to worsen in up-keeping and serviceability presented, even although,
doubling the effort, appropriation fund, and expenditure amounts on enhancement
them, improvement their serviceability, and increase their design age. All the above
necessitate searching on the reasons of falling performance levels in the design,
construction, operating, and maintenance at the same manner. The main reasons of
highways network failure are the fast appearance and increase in intensity of
deformation -with absence of periodically maintenance - in the pavement surfaces
specially asphaltic pavement or flexible pavement that represent the common and
dependable type in construction of that network.
The recent research concern in studying the forms and reasons of asphaltic
pavement deformations and definition their common reasons that sharing in appear
more than one form of deformations according to Iraqi specification and the
worldwide specification that depended in Iraq, in addition to compare them with
the deformation recorded in the studying region, which is the middle region in Iraq.
The recent research reach to that the increasing of traffic loading in weights and
repetition, weakness of Subgrade soil, increasing the volume changing in base
course duo to deficiency of proper drainage system, in addition to bad asphaltic
mixture design are the main reasons causes appearance the most risky types of
deformations in pavement surface, that extended in high percent reach to more than
62% depending on five of urban and rural highway sections in the studying region
in overall length about 114km approximately, with listing the differences in their
geometric design