Title : AN APPROACH TO CONDITION ASSESSMENT OF EXISTING STRUCTURE AND COMPLYING NON-CONFORMANCE OF NEW STRUCTURE FOR HIGHWAY PROJECT
Authors : Swapan Bagui
Publication : 13th – 16th February 2013
Volume :
Pages : 8-Jan
Price : 250
Abstract : Test results of different non-destructive tests; in-situ and laboratory tests are important data for rehabilitation and restoration of existing structure. The decision as to whether an existing structure is to be demolished or retained is taken based on such test results. This paper presents a systematic procedure for different tests of existing bridges, flyovers and new structures that are generally used in highway projects in India. Non-destructive tests are costly, and therefore a systematic testing procedure is required for the evaluation of the structure to minimize the cost of testing. Firstly, visual condition survey of existing structure shall be carried out. Based on condition survey data, structure shall be classified as excellent, good, fair, poor and very poor. Further testing shall be avoided for structures with excellent and good condition. Structures with fair to poor condition shall be tested for rebound hammer and other tests. Sample core shall be taken and the test results of core shall be checked for insitu strength of existing concrete. Ultrasonic tests shall be carried out to determine quality of concrete. In addition, corrosion, cover of existing reinforcement and other tests shall be carried out. Results shall be analysed for finalization of demolishing the existing structure or retain based on a proposed rating system. A statistical approach method has been proposed for complying non-conformance of a new structure comparing test results of various portions of the accepted sections and non-accepted sections of same or different structures.