Sreedhar Kalavagunta ¹, Sivakumar Naganathan ², Kamal Nasharuddin Bin Mustapha ²

Affiliations
1 Bentley Systems (Singapore) Pvt. Ltd. 30 Raffles Place, #12-02/30, Chevron House, SG
2 Universiti Tenaga Nasional, Jalan IKRAM-UNITEN, 43000, Kajang, Selangor, MY

Abstract

Analysis and design of axially compressed cold formed steel channel section presented in this paper was conducted through experimental study, design based on British standards and North American Specification for the design of cold-formed steel structural members. More than 18 laboratory experiments were undertaken first on these steel channel columns under axial compression. A series of parametric studies were also carried out by varying the thickness and column length. All of these columns failed by local and distortional buckling. The test results were compared with American (AISI-2007) and British Standards (BS5950-Part5) for the design of cold-formed steel structural members. The details of these investigation and the outcomes are presented in this paper.

Keywords

Cold Formed Channel Sections, Axially Compressed Members, BS5950, Effective Width Method, Direct Strength Method

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Sreedhar Kalavagunta ¹, Sivakumar Naganathan ², Kamal Nasharuddin Bin Mustapha ²

Affiliations
1 Universiti Tenaga Nasional, Jalan IKRAM UNITEN, 43000, Kajang, Selangor, MY
2 Universiti Tenaga Nasional, Jalan IKRAM-UNITEN, 43000, Kajang, Selangor, MY

Abstract

This paper presents a design method (BS5950-5) to predict the allowable load carrying capacity of cold formed steel channel section strengthened by carbon fiber reformed polymer composites applied to the web of the beam. A specimen is presented to illustrate the proposed design approach. The validity of the proposed design method has been verified by comparing with the experimental test results. A series of compression tests were conducted on plain and CFRP strengthened steel sections of different geometries. This paper also contains the consequences obtained by comparing the strengths of plain and CFRP strengthened steel columns using compression test. The findings showed that the strength of CFRP strengthened steel columns were up to 10% greater than plain cold form steel sections.

Keywords

CFRP, CFRP Strengthening, Axial Compression, Cold Formed Steel

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Nahushananda Chakravarthy ¹, Sivakumar Naganathan ¹, Raed Saleh Ali Ba Bhakri ¹, Sreedhar Kalavagunta ², Kamal Nasharuddin Bin Mustapha ¹, H. G. Phalguna ³

Affiliations
1 Department of Civil Engineering, Universiti Tenaga Nasional, 43000, Selangor, MY
2 Bentley Systems (Singapore) Pvt. Ltd, 048622, SG
3 Mercedes Benz Research and Development India Pvt Ltd, Bangalore - 560066, Karnataka, IN

Abstract

Objectives: Structural steel can be broadly classified into hot rolled steel and cold formed steel (CFS). CFS manufactured from roll forming or press braking operation. The main advantage of CFS sections are thin wall and light weight. These thin wall leads to buckling of structural member. This paper aims to study the capacity of Carbon Fibre Reinforced Polymer (CFRP) strengthened CFS channel beams, buckling behaviour, deflection and cost studies on CFRP strengthening. Methods/Statistical analysis: In this study three different length of CFS channel sections are selected for testing in which beams are tested for bending. All the beams were tested in plain section and CFRP strengthened series in universal testing machine. Findings: Experimental results shows the enhancement in capacity of beam due to CFRP strengthening. The local and distortional buckling modes were observed as failure modes. Experimental results were compared with maximum load resistance calculated by AISI specification which are in good agreement. Cost studies were compared on replacing a new member with CFRP strengthened channel member. Improvements/Applications: CFRP strengthening is suitable for enhancement of capacity of beams and repair. This CFRP strengthening technique can applied to reinforced concrete members, hot rolled steel, in filled steel tubes and bridges etc.

Keywords

Beam, CFRP, CFS, Channel, Cost, Repair

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Al-Mamon Yousef ¹, Zakaria Che Muda ¹, Sivakumar Naganathan ¹, Salmia Beddu ¹, Shojaeddin Jamali ¹

Affiliations
1 Department of Civil Engineering, Universiti Tenaga Nasional, Jalan IKRAM-UNITEN, 43000 Kajang, Selangor, MY

Abstract

Objectives: To investigate the post-tensioning behavior of the soil-cement interlocking bricks used in masonry wall subjected to out-of-plane loads. Methods/Statistical Analysis: Three types of wall specimen were tested with post-tensioned forces of 50% and 65% of maximum post-tension force. The wall specimens were tested horizontally after applying the post-tensioning force by applying two vertical point loads distributed equally along the wall. Findings: Results showed that service load and ultimate load for W1 are 6.2 KN and 9.5 KN respectively. The mentioned loads for W2 were 7 KN and 11.8 KN respectively. The maximum deflection occurred in W1 and W2 was 69 mm and 32 mm respectively. On the other hand, the service load and ultimate load for the post-tensioned wall with two tendons were found to be 14 KN and 20 KN respectively. The deflection in both cases was approximately same which it reaches up to 59mm. It can be concluded that post-tensioning level of interlocking bricks should be always from 60% to 65% in order to get optimum results for service ability and ultimate limit states. Application/Improvements: The post-tensioned wall developed using soil-cement interlocking blocks can be used in reinforced and post-tensioned masonry applications instead of conventional brick masonry. The post tensioning enhances the performance of brick masonry.

Keywords

Deflection, Masonry Wall, Post-Tensioning, Soil-Cement Interlocking Bricks, Ultimate Load

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Siti Nabihah Sadon ¹, Salmia Beddu ¹, Sivakumar Naganathan ¹, Nur Liyana Mohd Kamal ¹, Hamdan Hassan ²

Affiliations
1 Department of Civil Engineering, College of Engineering, Universiti Tenaga Nasional, Jln IKRAM-UNITEN, Kajang - 43000, Selangor, MY
2 Tenaga Nasional Berhad Research, No 1, Lorong Air Hitam, Kawasan Institusi Penyelidikan, Kajang - 43000,Selangor, MY

Abstract

Objective: This paper reviews the literature available on coal bottom ash (CBA) and its applications in building industry. Methods: The current trends on the reuse of CBA have been reviewed and the various properties of CBA are presented and discussed. Different percentage of CBA replacement in concrete was used. Findings: CBA were found thermally stable within the temperature range considered. Workability of fresh concrete containing CBA show a lower value due to the higher amount of replacement which required huge amount of water which effect the workability. Compressive strength of the concrete shows that it’s reached optimum strength beyond 28 days and no leachate of toxic elements in CBA was present. Application/Improvements: The review of the literature showed that the CBA was successfully recycle and applied for replacement as fine aggregate as well as coarse aggregate. It is concluded that the recycling of CBA as cement replacement material and also processing of CBA to develop nano-material are the future of CBA research.

Keywords

Coal Bottom Ash, Compressive Strength, Power Plant, Sustainable Material, Workability

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