Structural Behavior of Concrete Deep Beams Reinforced with Steel Ducts Eman A Al-Hassany, Labeeb S Al-Yassri Journal of Physics Conference Series, 2021 The aim of the research is to investigate the structural behavior of deep beams with a longitudinal opening reinforced by steel pipes. The experimental program included a test of (10) specimens with dimensions of (1500mm) length, (500mm) overall height and (250mm) width. One of these specimens was casted with solid section (without longitudinal opening) to keep it as a reference specimen for comparison purposes. The variables considered in this research were, the shape of the openings (circular, square, and rectangular) was adopted, opening size (three variable sizes of circular openings 4in,3in, and 2in) were used, in addition to the void’s ratio. The Load-deflection curves and crack patterns for the tested beams were discussed. The experimental results showed that the structural behavior of specimens with circular openings was approximately equal to the reference beam, where it gave efficiency about (103%) with respect to the reference beam. The specimens with square and rectangular openings gave an average load carrying capacity about (81%-35%) respectively with respect to the reference beam. Also, its noticed that the specimens containing rectangular openings were inefficient and caused early collapse. Using of steel pipes to reinforce the longitudinal opening was observed to be efficient for improving the load carrying capacity and stiffness of deep beams, the results showed that the ultimate load was increased by 22.6% compared to the beam with unreinforced opening.
Effect of different strengthening techniques on the behavior of one-way continuous slab with insufficient length of development Ruqayah D. Al-Shebawi, Labeeb S. Al-yassri Journal of Physics Conference Series, 2021 The purpose of this paper is to investigate the effect of the different strengthening techniques on the behavior of continuous one-way slab with insufficient length of development of rebars at the internal joint. The insufficient length of development of rebars in the zone of negative steel reinforcement leads to a reduction in force which has dangerous consequences that affect the structure and its serviceability. This study proposed three strengthening techniques to compensate the insufficient development length which including: internal strengthening by confining the lap zone by spiral bar, externally strengthened by CFRP sheet and steel plates. Six one-way concrete slabs with dimensions of 2200 mm length, 500 mm width, and 125 mm thickness were casted and tested under static load. The main variables adopted in this study are: the length of development, type of strengthening, and presence of construction joint. All slabs were loaded to failure. Form results, it’s found that the presence of construction joint and insufficient length of development of rebars at internal support of the continuous one-way slab had a tangible influence on the structural behavior, also, the insufficient length of development resulted in a deterioration of the structure, decrease in stiffness, and change in the mode failure. It was observed that the strengthening techniques used in this study able to compensate the reduction in stiffness and enhancing mode of failure. All the proposed strengthening techniques was efficient especially steel plates which gave a high increasing in ultimate load by about 16.14 % and by about 8.7-3.73% for the other.
Numerical analysis of one-way continuous slab with partial corrosion strengthened with different material Ammar Kareem Al-Najar, Labeeb S. AL-Yassri Al Qadisiyah Journal for Engineering Sciences, 2021 This paper investigates numerically the combined effects of a construction joint and reduction in the cross-section area of negative reinforcement in one-way continuous slab on the structural behavior and the efficiency of three types of strengthens techniques. In this paper, the modles were greated by ABAQUS (software) is used to numericaly represent the specimens and simulate the applied loading. This numerical study's models represent six one-way continuous slabs, as a part of a expermentail study. The specimen's dimensions were (2200 mm in length, 500 mm width ,and 100 mm thickness). Five of the six models had a vertical construction joint and reduced the negative reinforcement steel bars' cross-sectional area. The sixth specimen used as refreance. The proposed strengthening technique were: Carbon fiber Reinforced Polymers strips, 6 mm Carbon fiber Reinforced Polymers bars Near Surface Moutain technique and steel plates. All the proposed strengthening's applied to the tension side on the top face at the internal support. The program outcomes are represented visually as stresses distribution diagrams,load-deflection curves, and cracks pattern. The results from the numerical analysis compared to the experiment results. In the experiment, the reduction in the cross-section area resulting from partial corrosion happened in one span due to the outdoor atmosphere's exposure because of the stoppage in the concrete pouring, which also resulted in forming the construction joint. The results highlighted the construction joint's effect and the steel cross-sectional area reduction on the ultimate load and the deflection. The proposed strengthening methods improved the member's overall responses, and There was a good convergence between the numerical and experimental works that verify the specimens' observed behavior.
Experimental investigations on concrete beams reinforced with equivalent service steel pipe Labeeb Al-Yassri, Alaa Al-Khekani, Munaf Al-Ramahee Scientific Review Engineering and Environmental Sciences, 2021 Different techniques were employed for the passage of different utilities through structural elements. The reduction of the overall building weight was the main concern that needs to be achieved, especially for a multistory building. It can be done with the eliminating of a suspended ceiling with a portion of the beam’s weight by taking the advantages of the hollow sections. In this study, an equivalent reinforcement to the traditional ribbed reinforcement was employed to fabricate a reinforced concrete (RC) beam with a hollow section along the length of the beam. A steel pipe was used based on the equivalent moment from section analysis. Two diameters were selected of steel pipes as an equivalent to the commercial reinforcement. A total of four RC beams were cast and tested, two of them with traditional reinforcement and the other with steel pipe reinforcement. The comparison showed a promising result in terms of ductility, cracking pattern, ultimate strength, and mode of failure compared to the reference beam. The peak loads for the specimens with steel pipe were 160.6 kN and 184 kN, while they were 192 kN and 203.5 kN for the beams with traditional reinforcement.
Reduction of pollution caused by smoke from brick factories using a water system and reuse of water from brick production Mukhtar Dhajir Abbas, Alaa Mahdi Al-Khekany, Labeeb Saadoon Al-Yassri Iop Conference Series Materials Science and Engineering, 2020 Air pollution is an important contemporary issue and any attempt to mitigate pollution and the environmental impacts is considered significant. In Iraq, dark oil is used as the essential fuel for brick factories. Incomplete burning of this fuel discharges a black smoke, which contains substantial amounts of soot especially at the beginning of any operation. The main objective of this study is to investigate use of a system of spraying water to treat the black smoke that is emitted by brick factories, to reduce the pollution and reuse the industrially-generated black wastewater (IBW). In this study, five samples of water were used, comprising one sample of clean water (control sample) and four samples of IBW, which contained different quantities of soot according to the quantity black oil burned. The burning operation was reproduced by burning0.5,1, 1.5, 2 liters of black oil respectively for the four samples used. The IBW was tested in a laboratory of the environmental authority and it was found to be free from any increased concentration of heavy metals except copper(Cu) and zinc(Zn) elements with a ratio 0.02 to 0.20 mg/l and 2.25 to 2.61 mg/l respectively. The PH was neutral at around 7.3. Further laboratory tests of the IBW showed that it contained sulfates at about 426 to 646 mg/l, nitrates of 12.5 to 31 mg/l, and chlorides at 151 to 178 mg/l. The results showed that reuse of the IBW generated by the brick industry did not affect the compression strength for any samples compared with the control sample (zero soot), which means the adopted system gave a very good results, reducing pollution with the same compressive brick strength.
Experimental and numerical investigations of composite concrete steel flexural members with angle shear connectors under negative moment Periodicals of Engineering and Natural Sciences, 2020
An experimental investigation of hollow composite column reinforced by multi-skin square and round steel tube International Journal of Civil Engineering and Technology, 2018
