This article is presented to highlight one of the most innovative works undertaken by the LGSD engineering wing. During the middle of October 2012, the Executive Engineer, LSGD Division, Thiruvananthapuram District Panchayath got an SOS message from the PTA President of Poovar VHSS regarding the dangerous situation of the two storied main building of the Govt.VHSS Poovar in which classes are going on. The Executive Engineer immediately rushed to the spot and he was taken aback on seeing the existing condition of the L-shaped main building.
Condition of the building during mid October, 2012
The building was constructed around 20 years back. The proximity of the sea might have accelerated the deterioration. No substantial cracks were seen in the first floor of the building. May be this is due to the major repairs carried out some time back.
How to repair became a big question before the engineers. After detailed discussions with various agencies, the members of the Indian Concrete Institute and the experts in the College of Engineering, Trivandrum and the IIT Chennai, the engineers of the LSGD became convinced that repair and structural rehabilitation is possible and they moved into that direction.
The demand of the PTA and the Division member of the District Panchayath was to dismantle this building and to construct a new one. The Executive Engineer was able to convince them that the building can be repaired using latest technologies, after putting forward the following points.
The Executive Engineer then took the Public Works Standing Committee Chairman and the Working Group Chairperson of the District Panchayath to the site and convinced them also of the existing situation and also the modus operandi for the repairs and structural rehabilitation works. Thus the project materialized and this was included in the revision of projects and Administrative Sanction for rupees ten lakhs was obtained.
Meanwhile a letter was sent to the Manager, Centre for Continuing Education, College of Engineering, Thiruvananthapuram, requesting them to inspect the building and suggest remedial measures. An amount of Rs.28,090/- was also remitted for the test, report and remedial measures. They performed ReboundHammer Test as per IS:13311(Part 2):1992 and Ultra Sonic Pulse Velocity Test as per IS:13311(Part 1):1992.
Based on the test result they have found that the concrete is of grade M15 and that the concrete quality grading is ‘doubtful’. They have opined that the concrete in question is not sufficiently dense and is porous and because of that carbonation has occurred, penetrating the cover deep enough so as to reduce alkalinity of concrete which caused rusting of reinforcement. They have suggested the following method for the repairs and structural rehabilitation of the building.
If the reinforcement diameter has been reduced by more than 35%, put additional reinforcement there with necessary overlap or welding with the existing reinforcement. Fix shear keys of appropriate diameter at specified spacings.
|Anti corrosive coating on reinforcement||CERA ZINC-ZR|
|Epoxy bonding coat on concrete||CERABOND EP|
|Preparing polymer modified cement mortar||CERABOND SBR REPAIR|
|Wrapping the finished surface||Carbon Wrapping with Adhesive|
|Rust remover||CERA RUST CONVERTER|
|For holding stirrups||CERA-ANCHOR SET-S-HARDENER & CERA ANCHORSET BASE|
|Super Plasticizer||CERA HYPER PLAST XR W 40|
The work was started on 4.04.2013 and was completed on 20.08.2013 at an amount of Rs.8,78,020/-. The entire school authorities and the PTA are fully satisfied with this specialized work and the PTA honoured the Executive Engineer with an award of ‘Engineering Excellence’.
Thus a building which was in a distressed state and which would have been dismantled and reconstructed for which an amount of rupees two crores would have been spend, was saved at a cost of less than rupees nine lakhs adopting latest engineering materials and techniques. The efforts and initiatives taken by Sri. Er. Sam Vaidyanath, Assistant Executive Engineer, LSGD Parassala Sub Division and Smt.Anithakumari.M, Assistant Engineer, LSGD Poovar Section preparing estimate and executing this work are exemplary and should be appreciated. The inspection of the building and suggestive remedial measures were given by Prof.Biju.V and Prof.Mitra.D.C, Assistant Professors and Dr.Bindhu.K.R, Associate Professor of the College of Engineering, Thiruvananthapuram.