ISSN (Print): 2328-398X

ISSN (Online): 2328-3998

Editor-in-Chief: Mohammad Arif Kamal

Website: http://www.sciepub.com/journal/AJCEA

   

Article

Laboratory Investigation on Performance of Strengthening Techniques of RCC Beam

1Department of Civil Engineering, Khulna University of Engineering &Technology, Khulna-9203, Bangladesh


American Journal of Civil Engineering and Architecture. 2017, 5(1), 25-28
doi: 10.12691/ajcea-5-1-4
Copyright © 2017 Science and Education Publishing

Cite this paper:
Mir Abdul Kuddus, Izharul Haque Azad. Laboratory Investigation on Performance of Strengthening Techniques of RCC Beam. American Journal of Civil Engineering and Architecture. 2017; 5(1):25-28. doi: 10.12691/ajcea-5-1-4.

Correspondence to: Mir  Abdul Kuddus, Department of Civil Engineering, Khulna University of Engineering &Technology, Khulna-9203, Bangladesh. Email: mintu_ce_m@yahoo.com, kuddus@ce.kuet.ac.bd

Abstract

Reinforced concrete members are the most abundantly used construction elements in civil engineering. These members are normally designed to sustain various types of loads. But due to several reasons the members experience much more load beyond their capacity. Inadequate attention during design and construction of new additional RCC story in our country has raised question about the performance of existing structures. RCC beam is such an important member which sometimes needs to be strengthened. There are various methods of strengthening that have been studied by the researchers such as section enlargement, use of additional bars, use of FRP and CFRP, use of ferrocement, steel plates, etc. This thesis work aims to study and compare the effect of three distinct strengthening techniques- providing additional steel bars from underneath with U shaped shear reinforcement, use of wire mesh and providing single layer of geo-textile with adhesive. The experimental results show that the percentage increase in ultimate load carrying capacity for the steel, wire mesh and geo-textile were found to be 51.96%, 26.5% and 14.5% respectively with respect to reference beams. The value of deflection at failure were 5.63mm, 6.18mm and 5.83 mm respectively while for reference beam the value was 5.33mm. The performance of geo-textile was very poor. The use of wire mesh provides greater value of deflection at failure compared to other two methods but the increase in load carrying capacity is about half of that for steel bar. The application of additional steel is labor intensive compared to other two methods but in terms of ultimate load, it overweighs the advantages compared to other two strengthening techniques.

Keywords

References

[1]  Angelo, D., Francesco F, “Flexural Strengthening of RC Beams with Cement-Based Composite”, 10.1061/(ASCE)CC.1943-5614.0000218, American Society of Civil Engineers, J. Compos. Constr., 15(5): 707-720, 2011.
 
[2]  An, W., Saadatmanesh, H., and Ehsani, M. R., “RC beams strengthened with FRP plates. II: Analysis and parametric study. J. Struct. Engrg., ASCE, 117(11), 3434-3455, 1991.
 
[3]  Bansal, P. P., Kumar, M. & Kaushik, S., “Effect of wire mesh orientation on strength of beams retrofitted using ferrocement jackets”, International Journal of Engineering (IJE), Vol. 2, p. 8, 2008.
 
[4]  Diab Y.G.,. “Strengthening of RC Beams by Using Sprayed Concrete Experimental Approach.” Engineering Structures Vol. 20, pp. 631-643, 1998.
 
[5]  Kamran M. N., “Evaluation and repair methods to restore structural integrity of the reinforced concrete beams at Point Shilshole Condominium Building”, Washington, 2006.
 
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[6]  Kothandaraman S., and Vasudevan G., “Flexural Retrofitting of RC Beams Using External Bars at Soffit Level - An Experimental Study.” Construction and Building Materials Vol. 24, pp. 2208-2216, 2010.
 
[7]  Mohamed H., Kunieda M., and Nakamura H., “Strength and Ductility of RC Beams Strengthened with Steel-reinforced Strain Hardening Cementitious Composites.”Cement & Concrete Composites Vol. 34, pp.1061-1066, 2012.
 
[8]  Ong, K., Paramasivam, P. & Lim, C., “Flexural strengthening of reinforced concrete beams using ferrocement laminates”, Journal of Ferrocement, Vol. 22, pp. 331-342, 1992.
 
[9]  Khan S.U., Rafeeqi S.F.A., and Ayub T., “Strengthening of RCC Beams In Flexure Using Ferrocement. IJST, Transactions of Civil Engineering, Volume 37, 2013.
 
[10]  Zhang Y., “Repair and Strengthening of Reinforced Concrete Beams”, Honors Thesis, The Ohio State University, 2012.
 
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Article

Geotechnical Characterization of Local Materials Used in Road Construction in the Brazzaville Aera, Congo

1Ecole Nationale Supérieure Polytechnique, Université Marien NGOUABI

2Faculté des Sciences et Techniques, Université Marien NGOUABI, B.P. 69 Brazzaville, CONGO/Centre de Recherches Géologiques et Minières, CRGM

3Groupe de Recherches sur les Propriétés Physico - Chimiques et Minérales des Matériaux, Faculté des Sciences et Techniques, Université Marien NGOUABI, B.P. 69 Brazzaville, CONGO/Centre de Recherches Géologiques et Minières, CRGM

4Laboratoire Mécanique, Energétique et Ingénierie, Ecole Nationale Supérieure Polytechnique, Université Marien NGOUABI

5Faculté des Sciences et Techniques, Université Marien NGOUABI

6Laboratoire de Photonique et de Nano-Fabrication, Faculté des sciences et Techniques Université Cheikh Anta Diop de Dakar (UCAD) B.P. 25114 Dakar-Fann Dakar, Senegal


American Journal of Civil Engineering and Architecture. 2017, 5(1), 29-34
doi: 10.12691/ajcea-5-1-5
Copyright © 2017 Science and Education Publishing

Cite this paper:
David Bilembi, Hilaire Elenga, Timothée Nsongo, Bernard Mabiala, Adolphe Kimpena, Balla Diop Ngom, Aboubaker Chedikh Beye. Geotechnical Characterization of Local Materials Used in Road Construction in the Brazzaville Aera, Congo. American Journal of Civil Engineering and Architecture. 2017; 5(1):29-34. doi: 10.12691/ajcea-5-1-5.

Correspondence to: Balla  Diop Ngom, Laboratoire de Photonique et de Nano-Fabrication, Faculté des sciences et Techniques Université Cheikh Anta Diop de Dakar (UCAD) B.P. 25114 Dakar-Fann Dakar, Senegal. Email: nsongo@yahoo.com, bdngom@gmail.com

Abstract

The survey of the road construction materials within the Brazzaville Area in the Congo was conducted on the geotechnical data of materials collected from different sites in order to establish a correlation with the norms of their use in Civil Engineering fields. These data include grading curves, consistency limits for the fine fraction, modified Proctor test results and CBR tests. Those data were subjected to classical statistic processing (characterization of every geotechnical parameter variability, study of correlations between parameters). The survey concludes that the material samples analyzed present so close physical properties that they cannot be clearly distinguished through statistical analysis. The overall analysis of the CBR index values varies depending on the materials used. As a consequence these variations cause the deterioration of the pavement structure. The constituents that comply with the above-defined physical properties can be used as materials of a pavement structural layer. The deterioration effects and the granular fragmentation from the Inkisi formations help appreciate the Micro-Deval coefficient and the Los Angeles coefficient, for the figures of both coefficients and result in high figures which means better basic mechanical properties of the foundation and structural layers.

Keywords

References

[1]  Z. P. B. Bohi, 2008. Charaterization of lateritic soils used in road construction: case study of the region of Agnéby (côte d’ivoire), Ph.D thesis, Ecole Nationale de Ponts et Chaussées, Champs-sur-Marne, Charaterization of lateritic soils used in road construction Doctoral Thesis.
 
[2]  G. Samba and D. Nganga, 2011, Rainfall variability in Congo-Brazzaville 1932-2007. Int. J. Climatol. Published online in Wiley online library 20.
 
[3]  P. Dadet, Explanatory note of the Congo Republic Geological map 1/500000 ( Area between parallels 2 & 5 South).
 
[4]  Mém. Du BRGM, n° 70, 1969. Explanatory note of the Cong Republic Geological map 1/500000 (Area between parallels 2 & 5 South).
 
[5]  A. Le Marechal, 1978. A Contribution to the Study of the Batéké Plateaux soils, ORSTOM, Serv. Géol., Brazzaville.
 
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[6]  Laboratoire B.C.B.T.P, 2007. Geotechnical Survey of the non-processed base 0/31.5, Brazzaville, Congo.
 
[7]  J.J. Chauvin, les sables, 1987. Road user’s Practical guideline, ed. Isted.
 
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Article

Performance of Concrete Filled Steel Tubular Columns

1Ex Faculty/ Head of Civil Engineering Department, NUST, Risalpur, Pakistan

2Presently Senior Consulting Engineer, Black & Veatch, Toronto, Canada


American Journal of Civil Engineering and Architecture. 2017, 5(2), 35-39
doi: 10.12691/ajcea-5-2-1
Copyright © 2017 Science and Education Publishing

Cite this paper:
T. Kibriya. Performance of Concrete Filled Steel Tubular Columns. American Journal of Civil Engineering and Architecture. 2017; 5(2):35-39. doi: 10.12691/ajcea-5-2-1.

Correspondence to: T.  Kibriya, Ex Faculty/ Head of Civil Engineering Department, NUST, Risalpur, Pakistan. Email: t_kibriya@yahoo.com

Abstract

Recent advancements in the availability of higher strength steels, better coating materials for protection and high strengths/performance concretes have expanded the scope of concrete filled steel composite columns with wide ranging applications in various structural systems with ease of construction, highly increased strengths and better performance. This experimental study is carried out on the behavior of short, concrete filled steel tubular columns axially loaded in compression to failure. Three dimensional confinement effect of concrete along with support provided by concrete to the thin walls of steel tube to prevent local buckling had a composite effect on the strength of the composite column increasing the compressive strengths by almost 300 to 400%. In addition to the concrete core, the parameters for the testing were shape of the steel tube and its diameter-to-thickness ratio. It has been observed that ultimate strength of concrete filled steel tubes under concentric compression behavior is considerably affected by the thickness of the steel tube, as well as by the shape of its cross section. Confining effect in circular CFST columns improves their strength, appreciably. The axial load-deformation behavior of columns is remarkably affected by the cross-sectional shape, diameter/width-to-thickness ratio of the steel tube, and the strength of the filled concrete. The load deformation relationship for circular columns showed strain-hardening or elastic perfectly plastic behavior after yielding.

Keywords

References

[1]  Georgios Giakoumelis and Dennis Lam “Axial capacity of circular concrete-filled tube columns, Journal of Constructional Steel Research 60 (2004) 1049-1068.
 
[2]  Lin Hai Han, Zhong Tao and Wei Liu in “Effects of Sustained Load on Concrete-Filled Hollow Structural Steel Columns” Journal of Structural Engineering, ASCE, September 2004).
 
[3]  C.S. Huang, Y.K. Yeh, G.Y. Liu, H.T. Hu, K.C. Tsai, Y.T.Weng, S.H. Wang and M.H.Wu “Axial load behavior of stiffened concrete-filled steel columns, Journal of Structural Engineering, ASCE, September 2002.
 
[4]  Martin D. O’ Shea, “Design of Circular Thin-Walled Concrete Filled Steel Tubes”, Journal of Structural Engineering, ASCE, November 2000.
 
[5]  Kenji Sakino, Hiroyuki Nakahara, Shosuke Morino and Isao Nishiyama, “Behavior of Centrally Loaded Concrete-Filled Steel Tube Short Columns”. Journal of Structural Engineering, ASCE, February 2004.
 
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[6]  Eurocode 4: Design of composite steel and concrete structures.
 
[7]  LRFD Manual of Steel Construction third edition 2001.
 
[8]  Mathias Johansson and Kent Gylltofl “Mechanical behavior of circular steel-concrete composite stub columns” Journal of Structural Engineering, ASCE, August 2002.
 
[9]  Lin-Hai Han and You-Fu Yang “Cyclic performance of concrete-filled steel CHS columns under flexural loading” Journal of Constructional Steel Research 61 (2005) 423-452.
 
[10]  Kibriya, T. & Baig, N. “Performance of composite concrete columns with steel casing” Proceedings of IV Regional Conference on Civil Engineering Technology, ASCE/ESIE 7-9 June, 2005, Cairo, Egypt.
 
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