Engineering and Technology Journal

Mechanical Characteristics and Self-Monitoring Technique of Smart Cementitious Mixtures with Carbon Fiber and Graphite Powder as Hybrid Functional Additives

Raid D. Abdullah; Ali Al-Dahawi; Hussein H. Zghair

Volume 40, Issue 11 , November 2022, , Page 1537-1547

https://doi.org/10.30684/etj.2022.134097.1220

Abstract

In this paper, the self-sensing properties of cementitious composites under compressive loads were investigated by utilizing hybrid functional fillers, which are responsible for creating ... Read More ...

Investigate the Effect of Different Kinds of Discontinuous Fibers on the Mechanical Properties of Epoxy Matrix Composite Materials

Ahmed Muhammad; Ibrahim A. Atiyah; Hamza M. Kamal; Ahmed M. Al-Mukhtar

Volume 36, 5A , May 2018, , Page 520-522

https://doi.org/10.30684/etj.36.5A.7

Abstract

The composite manufacturing has been a wide variety of applications. The low density, stiffness, and weight to strength ratio giving these materials significant mechanical properties ... Read More ...

Experimental Behavior of Self Compacting Concrete Corbels Strengthened with External CFRP

Sarmad Sh. Abdulqader; Basil Salah Al-Shathr; Ali Kh. Hasan

Volume 36, 2A , February 2018, , Page 154-162

https://doi.org/10.30684/etj.36.2A.6

Abstract

This research aims to study the influence of using Carbon Fiber Reinforced Polymer (CFRP) strips as an external strengthened and repairing material on the behavior of self-compacting ... Read More ... This research aims to study the influence of using Carbon Fiber Reinforced Polymer (CFRP) strips as an external strengthened and repairing material on the behavior of self-compacting concrete (SCC) Corbels. The experimental work involved testing twenty self-compacting concrete corbels specimens. The experimental work is divided into two parts; the first part consists of three groups to investigate the most effective direction, position, bonding type and amount of CFRP strips on the behavior of corbels and utilized it in practice, also to strengthen new variables that are investigated in the second part. Two groups in part one are strengthened with different numbers of inclined and horizontal direction of CFRP strips, while in the third group the specimens were strengthened with strips of CFRP having different directions and bond types to improve the strength capacity and behavior of corbels. This improvement is represented by increase cracking load by about (94)% and increase in their ultimate load capacity of strengthening corbels which varies from about (19 to 88)%. While the second part of experimental work included the following variables: shear span to effective depth ratio (a/d), amount of horizontal steel reinforcement stirrups and repaired damaged corbels. The reinforced concrete corbels in this part were strengthened and repaired by CFRP strips depending on optimum result that is produced from part one wherefrom position, direction and amount are considered. It was found for un-strengthened and strengthened corbels having same horizontal secondary reinforcement stirrups that when (a/d) ratio decreases from 0.65 to 0.4 causes increase in cracking and ultimate loads reach (55)% and (35.41)% respectively. For un-strengthened and strengthened corbels having same (a/d) ratio, it was found an increase in cracking load which varies from (6.66 to 34.78)% and from (18.18 to 52.63) % in ultimate load when horizontal secondary reinforcement stirrups are increased. It was also found repairing SCC corbels with CFRP strips causes an increase in ultimate load reaching up to (50)% with respect to un-strengthened specimens. From results it is concluded that strengthened or repaired corbels present stiffer load deflection response than corresponding un-strengthened corbel (control corbel).

Mechanical and Physical Properties of Nano Carbon Tube with Carbon Fiber Reinforced with Polyester Resin

M. Subhi; E. S. AL-Hassani; A.B. Abdul-Hussein

Volume 35, 5A , May 2017, , Page 465-472

https://doi.org/10.30684/etj.35.5A.5

Abstract

In this research, study some physical and mechanical properties of polymernano composites. The polymernano composites based on unsaturated polyester resin reinforced with carbon fibers ... Read More ...

Study the Effect of Glass and Carbon Fibers on the Firebrick Properties

H.A. Jaber

Volume 35, 4A , April 2017, , Page 391-398

https://doi.org/10.30684/etj.35.4A.11

Abstract

This work was carried out to investigate effect of glass fiber (GF) and carbon fiber (CF) on kaolin-clay firebrick properties. GF and CF are considered inorganic fibers with application ... Read More ...

Effect of Al2O3 Powder on Some Mechanical and Physical Properties for Unsaturated Polyester Resin Hybrid Composites Materials Reinforced by Carbon and Glass Fibers

Reem Alaa Mohammed

Volume 34, 12A , December 2016, , Page 2371-2379

https://doi.org/10.30684/etj.34.12A.18

Abstract

This research is a study of the effect of Al2O3 powder on physical and mechanical properties of the polymer hybrid composites based on unsaturated polyester resin reinforced with carbon ... Read More ...

Direct Shear Behavior of Carbon Fiber Reinforced Self- Compacting Concrete

Kaiss F. Sarsam; Tareq S. Al-Attar; Ghzwan Ghanim Jumah

Volume 32, Issue 10 , October 2014, , Page 2491-2513

https://doi.org/10.30684/etj.32.10A.13

Abstract

This paperrepresents an experimental and statistical investigation for the behavior of connectionpoints produced by using self-compacting concrete and subjected to direct shear. The ... Read More ... This paperrepresents an experimental and statistical investigation for the behavior of connectionpoints produced by using self-compacting concrete and subjected to direct shear. The investigation also includes the effect of carbon fiber inclusion as reinforcement on self-compacting concrete (SCC) behavior in direct shear. This study gives results of sixteen push-off or direct shear specimens in four groups. Variations include volume fraction for carbon fiber (V_f= 0.00, 0.50, 0.75 and 1.00) % for every percentage change in the steel reinforcement. The steel reinforcement parameter ρ_vf f_y values are (0.00, 2.66, 5.33 and 7.99) MPa(where ρ_vf varies from 0.00 to 0.0173 and f_y=585.7MPa) . The main material properties studied include compressive strength, splitting tensile strength and modulus of rupture. Measurements of deformations were made throughout testing of shear specimens. The dimension of the shear plane in the push-off specimenswas 170x185 mm. The shear reinforcement was normal to the shear plane. Specimens were cast by using SCC which is a type of high performance concreteand reinforced with carbon fiber. This work aims to investigate the direct shear behavior of SCC with or without carbon fiber at constant water to cementitious materials ratio of 0.3 by weight. It is found that using carbon fiber increased the direct shear strength. However, carbon fiber alone (without reinforcement) leads to brittle failure. In contrast, adding rebars leads to higher strain and more ductile behavior-increased shear capacity is obtained when higher steel quantity is used. The aim of adding carbon fibers was the increase of the horizontal strain (displacement). It was found that the optimum percentage of volume fraction was 0.75 % for fresh and hardened concrete. In addition, the effects of carbon fiber on compressive strength of SCC lead to a drop in compressive strength (f_c^') compared with reference specimens. This drop in f_c^' was 2.39, 8.38 and 13.58% for V_f=0.50, 0.75 and 1.00%, respectively. In contrast, the splitting tensile strength increased by 3.34, 31.2 and 18.2 as compared with the cylinder strength without carbon fibers atV_f equal to0.50, 0.75 and 1.00% respectively. The modulus of rupture increased by [11.9, 21.99 and 13.83%] as compared with SCC without carbon fibers at〖 V〗_f equal to 0.50, 0.75 and 1.00% respectively. Based on push-off tests results for this work and those available in the literature, two statisticalmodels have been established using regression analysis. Four variables f_c^',f_ct,ρ_vf f_y and V_f, were included in these models. Both models showed good representation according to their coefficients of variation (COV)values. Verification of the models were done by using 273 observations from literature and the present work.

Coating of Carbon Fibers With Calcium Phosphate by Sol- Gel Method

Sewench N. Rafeeq; Wafaa A. Husaien; Russel Rushdi Ghanim

Volume 32, Issue 5 , June 2014, , Page 1117-1128

https://doi.org/10.30684/etj.32.5A.3

Abstract

Sol-gel technique has been used to coat carbon fibers with calcium phosphate to improve the esthetic of black carbon fibers as it's biocompatible. To improve bonding between carbon ... Read More ...

Strengthening of Continuous Reinforced Concrete Beams by Cfrp Laminates

Sabih Z. Al-Sarraf; Hisham Al-Hassani; Ali S. Al-Jebouri

Volume 31, 2 A , February 2013, , Page 330-344

https://doi.org/10.30684/etj.31.2A.10

Abstract

Experimental investigations of the behavior of reinforced concrete three-span continuous beams with 1200 mm length for each span, with cross-section 120 mm width and 180 mm depth strengthened ... Read More ...

Effect of Addition Carbon And Glass Fibers On Bond Strength of Steel Reinforcement and Normal Concrete

Rana Hashim Ghedan

Volume 31, 1A , January 2013, , Page 81-97

https://doi.org/10.30684/etj.2013.71250

Abstract

The concept of composite materials using fibers as reinforcement is not new. The aim of composing materials is to improve some properties of the original materials. In civil engineering, ... Read More ...

Keywords = Carbon Fiber

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