TEACHING EXPERIENCE:
- Teacher (Lecturer) with undergraduate students of College of engineering, University of Duhok and University of Zakho. Subjects (Concrete Technology- Engineering Mechanics- Building Construction- Mechanics of Engineering- Reinforced Concrete Design- Design of Reinforced Concrete Structures- Steel Design- Structural Engineering Software).
- Teacher (Ass. Lecturer) with undergraduate students of College of engineering, University of Duhok. Subjects (Mechanics of Engineering- Strength of Materials- Theory of Structures- R. Concrete Design- R. Concrete Structures- Steel Design- ETABS®- Graduation projects of 4th year students).
- Instructor with undergraduate students of College of engineering, University of Duhok. Subjects (Practical surveying- Building materials lab.- Transportation lab.- Descriptive engineering).
-Training Courses instructor. Training Courses, Work with NGOs institutes in management, training and communications.
Environmentally friendly building materials known as geopolymers are made by combining high-alkalinity solutions with powder components rich in silica and alumina. It has long been known that adding fibers to the matrix phase can improve the mechanical characteristics of composite materials made for various uses. Among these are SIFCON composites, which are made by first inserting the fibers into the mold and then packing the gaps between the fibers with an extremely fluid matrix phase. The present study looked over the mechanical properties and efficiency of cement-based and geopolymer-based slurry infiltrated fiber concrete SIFCON and G-SIFCON. In the current study, for the production of both SIFCON and G-SIFCON composites, 7.5% steel fiber by volume fraction was utilized for this purpose. Therefore, sets of concrete specimens including cylinders and prisms were prepared and tested in accordance with standard specifications. The results obtained from the conducted tests prove that the 7.5% of steel fiber ratio can be used effectively to improve the mechanical performance of G-SIFCON and SIFCON composites. Furthermore, the cement-based SIFCON can be effectively replaced by fly ash-based geopolymers. Also, for composites made with fly ash-based geopolymers (G-SIFCON), high compressive strength slurries may exhibit more enhancement in mechanical properties than normal strength slurries.
The use of concrete as a construction material has become increasingly popular due to its high compressive strength and durability. It is possible to reduce the workability of a regular mortar by approximately four percent by adding up to ten percent recycled concrete powder (RC). This is due to the fact that the larger porosity of the adhering mortar with RC material makes water more necessary. The addition of fly ash (FA) and RC to the mixture has the potential to boost the workability of the mortars by as much as 11.8% respectively. This strategy makes it much simpler to cut down on the increased water use that is related with RC on its own. In general, the fresh-state density of binary mortars that contain RC or FA is lower than that of traditional mortar with the same composition. However, the density that is produced as a result of combining both increases is more than the density that is produced by utilizing either RC or FA. The compressive and flexural strengths of mortars that contain RC (five to ten percent) are relatively decreased when compared to those of regular mortar. The compressive strength decreases by around 9.8% to 14.3% after a year of curing, whereas the flexural strength decreases by approximately 2.6% to 5.0% after the same amount of time. With the addition of FA to mortars that already contain RC, it is possible to improve the mechanical performance of the mortars. When compared to the compressive and flexural strengths of traditional mortar, the ternary mortars exhibit equivalent levels of strength. The ternary mortars have an RC content of 5% and an FA content of 10%. The results of this experiment make it abundantly clear that the best amount to replace cement is 10% RC and 20% FA. A mechanical point of view, the findings of this experiment make this abundantly clear.
2024-06
Case Studies in Construction Materials
(Issue : 17)
(Volume : 01281)
Mechanical properties and efficiency of SIFCON samples at elevated temperature cured with standard and accelerated method
This research shows the results and conclusions of an experimental study that aims to shed light
on the mechanical performance of Slurry Infiltrated Fiber Concrete (SIFCON) (i.e. compressive
strength, splitting tensile strength, flexural strength, Poisson’s ratio, elastic modulus, and ultrasonic
pulse velocity (UPV) and explore its efficiency at elevated temperature (i.e. 200, 400 and
600 ◦C) with different steel fiber ratios of 5 %, 7.5 %, and 10 % cured standard and in boiling
water (accelerated curing). Hence, sets of cylinders and prisms are cast and tested under ASTM
standard conditions. The results indicate that mechanical properties improve by increasing the
steel fiber ratio up to 7.5 % in the case of a standard curing system, but more improvement is
achieved with a steel fiber ratio up to 10 % in case of accelerated curing with boiling water. Also,
the results indicate the superiority of the accelerated curing method for flexural and splitting
tensile strength. Fly ash has a good contribution to the enhancement of mechanical performance
of SIFCON with high steel fiber ratios. A decreasing and drastic reduction in compressive strength
with increasing temperature above 200 and 400 ◦C for control specimens and SIFCON specimens
with fiber ratios of 5 %, respectively are observed. While a dramatic gain in the strength of
SIFCON samples with fiber ratios of 7.5 % and 10 % is concluded. High ratios of steel fiber can
retard the spalling of concrete; hence it makes SIFCON the unique material for resisting explosive
loads.
2022-01
Journal of Cleaner Production
(Issue : 324)
(Volume : 129251)
Engineering properties of sustainable green concrete incorporating eco-friendly aggregate of crumb rubber: A review
The disposal of waste rubber tires has become a main ecological issue around the world. Each year, millions of
tires are disposed of, buried, or thrown away, which is a severe hazard for the environment due to its prolonged
degrading period. Therefore, recycling waste rubber as aggregates as a supplemental construction material is
beneficial. The usage of crumbs rubber (CR) would be led to sustainable utilization of waste material, which
would preserve depleting natural aggregate sources and protecting the environment. This paper reviews the
published research on the performance of concrete containing CR as eco-friendly aggregates. Moreover, it
highlights the impact in terms of aggregate substitution content, form, size, and waste treatment on the fresh and
mechanical properties of crumb rubber concrete (CRC). The paper also aims to update the database for further
experimental and numerical research on rubberized concrete.
2021-01
Elsevier, Engineering Science and Technology, an International Journal
(Issue : 20)
(Volume : 20)
Mechanical properties and spalling at elevated temperature of high performance concrete made with reactive and waste inert powders
In this article, the efficiency of waste glass powder was investigated in enhancing the mechanical properties
of concrete at high temperature. Chemical composition of this powder reveals that it plays good
role as effective inert very fine material in concrete strength improvement. Conventional reactive pozzolanic
powder of silica fume was used also in present work to show the degradation degree in concrete
strength under firing in comparison to concrete made with waste glass powder. The experimental program
was comprised of tests for examining fire resistance and mechanical properties of high strength
concrete (HSC) after firing. Fifty-six concrete cylinders and prisms were manufactured for measuring
their compressive and flexural strengths, modulus of elasticity and stress-strain behavior at high temperature.
Failure modes were considered also for the specimens after fire exposure. Results demonstrate the
great role of waste glass powder in conserving residual strength at high temperature. Accordingly, it is
proved that the HSC made with waste glass powder has strength at high temperature more than that
for concrete fabricated by silica fume.
2017-01
Journal of University of Duhok (JDU)
(Issue : 1)
(Volume : 20)
Flexural behavior of reinforced concrete beams made with ordinary and high strength concretes: effect of interfacial roughness between old and new concretes
Present endeavor is devoted to investigate the flexural strength of beams fabricated by ordinary concrete (OC) and retrofitted with high strength concrete (HSC). Old part of beams is represented the deteriorated concrete; while the new part is referred to retrofitted portion of the deteriorated beam. Bond strength between two concrete parts of beam was enhanced via preparing rough interfacial surface in various ways, namely, sand blast, holes, grooves and steel brush. Experimental measurements are given in terms of flexural load – deflection relationship and cracking pattern of the beams. It is demonstrated that the beams with sand blast interfacial surface show reasonable performance with high flexural toughness and safer cracking at collapse.
2017-01
ZANCO Journal of Pure and Applied Sciences
(Issue : 28)
(Volume : 4)
Experimental Study of CFRP Confined Low Strength R.C. Columns under Concentric Loads
The paper presents results of an experimental investigation carried out on reinforced, low strength concrete columns strengthened by Carbon Fiber Reinforced Polymers (CFRP). The columns were tested under concentric compression until failure. The shape and the slenderness of the column, the thickness and the configuration of confinement were the basic parameters considered in the experimental program. The main objective of the investigation was to study the effectiveness of using CFRP as an external strengthening method to increase the ultimate load of the low concrete strength columns. Using the CFRP enhanced the ultimate load of the columns for all specimens, the increase in ultimate load ranges between 15 % and 291 % compared to the control specimens. The partial confinement is not as effective in increasing the column ultimate load as compared with full confinement. The CFRP confinement is not as effective in increasing the ultimate load of square columns as for circular columns. The gain in ultimate load increases as the number of CFRP wraps. The strength behavior was affected by the cross-section shape and slenderness ratio.
2016-10
International Journal of Civil Engineering (IJCE)
(Issue : 3)
(Volume : 2)
Shear strength and behavior of ultra-high performance fiber Reinforced concrete (UHPC) deep beams without web reinforcement
Ultra-high performance fiber reinforced concrete (UHPC) is a new class of concrete that has been developed in
recent decades, it has enhanced properties such as; very high compressive strength, improved tensile strength. In this study,
three types of concrete were used based on the compressive strength of concrete, named; Normal Strength Concrete (NSC)
of (𝑓′
𝑐 = 42 MPa), High Strength Concrete (HSC) of (𝑓′
𝑐 = 63.75 MPa) and Ultra High Performance Concrete (UHPC)
of (𝑓′
𝑐 = 134.5 MPa).The experimental program included casting and testing of fifteen reinforced concrete deep beams
without web reinforcement (stirrups), nine specimens of (UHPC), three specimens of (HSC) and three specimens of
(NSC), in order to study the shear strength and behavior of deep beams under two point loading. Considered variables
were; the compressive strength of concrete (42, 63.75 and 134.5 MPa), the shear span to depth ratio (a/d) (1, 1.5 and 2) and
over all depth of the beam (h) (180, 240 and 300 mm), while the width of all beams was (120 mm). The experimental
results showed that the compressive strength of concrete also the shear span to depth ratio (a/d) has a significant effect on
failure load, while the increase in overall depth of the beam from (180 to 240) mm reduces the nominal shear stress
significantly, but beyond which no obvious size effect can be seen.
2013-07
Thesis
2022-11-22
INVESTIGATION OF THE MECHANICAL PROPERTIES AND DURABILITY OF SLURRY INFILTRATED FIBER CONCRETE (SIFCON) USING DIFFERENT CURING METHODS
PHD
2022
2012-06-01
SHEAR STRENGTH AND BEHAVIOR OF ULTRA-HIGH PERFORMANCE FIBER REINFORCED CONCRETE (UHPC) DEEP BEAMS WITHOUT WEB REINFORCEMENT
