Decision Making for Retrofitting in Existing RCC Structures

In order to assess the condition of the RCC structure, a thorough evaluation was performed. The evaluation determined the structural condition, the need for repair or maintenance and provided an indication as to the safety and expected remaining service life of the structure. The testing consisted of: 1) A visual inspection of the exterior exposed elements to determine if there were any obvious signs of distress, deflection or deterioration in the structure. 2) The inspection of the structure to determine the condition of the structure. This is essential as we found that the structure can appear to be in a very good condition from outside, but could be suffering from extreme structural distress from inside. 3) Selective concrete/steel removal to examine the condition of the underlying reinforcing steel. 4) Materials testing to determine steel/concrete compressive strength, carbonation, chloride content. Objectives of the overall investigation: The overall objective of the investigation carried out for the structure is to obtain an up to date account of the health condition of the structure so that appropriate repair measures can be taken up to make up for the damages sustained. Keeping this in view the basic objectives of the investigation formulated are as given below. a) To assess the existing condition of the structural elements. b) To determine the extent of damages in the structure, so as to undertake suitable remedial measures for rehabilitation of the structure. Planning and Survey and Methodlogy Walk over survey: First and foremost activity in a condition survey and structural investigation, especially in distressed superstructure, is a walk over survey or systematic visual inspection so as to gather readily available information about the structure in question. Further, careful visual observation of typical crack pattern and the nature of the spalling can furnish valuable information regarding the distresses. This in turn provides an idea about the degree of damage encountered in the concrete and hence the extent of repair required. A systematic visual observation has been recorded in this investigation and the findings are presented in later part of this report. Selection of tests: Tests are selected on the basis of the requirements of the overall objectives of the investigation and the observations made during a quick walk over survey. In this investigation, following in-situ and laboratory tests were considered necessary for achieving the overall objectives stated earlier for the structure. Various Test were Conducted for the evaluation of the Structure: METHODLOGY 1. Visual Survey 2. Test Plan 3. Sample and Data Collection 4. Structure Stability Analysis & Retrofitting