Informatics Publishing Limited

Akhtar Gul ¹, Bashir Alam ², Fayaz A. Khan ¹, Yasir Irfan Badrashi ¹, Khan Shahzada ²

Affiliations
1 Department of Civil Engineering, University of Engineering & Technology, Peshawar Campus-III, Bannu, PK
2 Department of Civil Engineering, University of Engineering & Technology, Peshawar, PK

Abstract

The most implementable and favorable technique, used for the flexural strengthening of reinforced concrete (RC) beams is the attachment of external steel members. Attachment of external steel sections or fiber reinforced polymers is considered as a common technique used for the enhancement of flexural capacity of the existing structural elements. To investigate and evaluate the flexural capacity of reinforced concrete beams, strengthened with external steel bars, a research study was carried out and is presented in this paper. Three reinforced concrete beams reinforced with minimum reinforcement ratio were constructed and tested. Two beams were strengthened by attaching external steel bars with bottom layer of shear reinforcement and one specimen without external steel bars was tested as control sample. The area of reinforcement to be provided as external steel bars was calculated on the basis of maximum steel ratio as per the ACI-(318-08) 10.3.5. Welding was used for the attachment of the external steel bars to the existing shear reinforcement. All the three beams were tested in positive bending under third point loading as per the ASTM C78/C78M-10. Test result shows that great enhancement in strength capacity and better distribution of cracks may be achieved by using this technique of flexural strengthening of beam.

Keywords

Strengthening and Evaluation, Beams, Steel Bars, Cracks, Flexural Capacity.

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Fazal-E-Jalal ¹, Khan Shahzada ², Salman Saeed ³, Irshad Ahmad ², Kaffayatullah Khan ⁴

Affiliations
1 Department of Civil Engineering, COMSATS, Abbottabad-22010, PK
2 Department of Civil Engineering, University of Engineering and Technology, Peshawar-25000, PK
3 National Institute of Urban Infrastructure Planning, University of Engineering and Technology-25000, PK
4 Civil and Environmental Engineering Department, King Faisal University, SA

Abstract

This paper reports an investigation of suitability of industrial and agricultural waste (i.e. marble waste and bagasse ash) on the geotechnical properties of medium expansive soils, located across Kohat city, of Khyber Pakhtunkhwa Pakistan. As most part of Pakistan falls in semi-arid zone, the geology and climatic conditions in Kohat produce widespread distribution of swelling clays. Such soils possesses a variety of undesirable characteristics i.e. immensely affect the pavements, boundary walls, slab-on-grade members and other infrastructure. Soil samples were collected, cataloged, subjected to multitude of geotechnical tests and submitted to anti-expansive treatment using prescribed percentages of stabilizers. The investigation includes chemical analysis i.e. X-Ray Diffraction (XRD) Analysis, Scanning Electron Microscopy (SEM), X-Ray Fluorescence (XRF) tests, and evaluation of geotechnical properties such as moisture-density relationships, Atterberg limits, unconfined compressive strength, swell pressure and free swell. When blended with both stabilizer materials, the compatibility and strength characteristics are improved and plasticity is significantly reduced. From the viewpoint of economy, blending of soil using 4-6% bagasse ash and/or 8-10% marble industrial waste is recommended. This paper summarizes the results of identification, characterization and stabilization techniques to eliminate the expansively of swelling soils.

Keywords

Expansive Soil, Stabilization of Soils, XRD, SEM, Marble Industrial Waste, Bagasse Ash.

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