Structural Audit & Repairs
Sturctural audit is an overall health and performance check-up of a structure akin to doctor examining a patient. Structural audit entails analyses and suggestions about repairs and retrofitting measures required for buildings to perform better during their service life. Primary purpose of audit is to save human lives due to building collapse and to understand the condition of the structure and to find critical areas. We are of the opinion that a detailed survey must be carried out. This shall help to decide the remedial measure along with the repair cost.
Audits are carried out for following reasons:
- Assessment of distress in structural members, corrosion, dampness, plaster defects, etc.
- Assessment for seismic strength as the structure deteriorates with time
- Assessment for loss of static strength of the structure over passage of time
- Assessment of increased loading due to change of use, layout changes, etc.
The general scope of work includes:
A. Carrying out structural audit – visual survey, estimate and distressing mapping :
- Carrying out visual survey and preparing distressed mapping on available architectural and/or structural drawings.
- Identify and provide remedy for three types of leakages:
- External leakage
- Inter-flat leakage
- Inner-wall leakage
- Prepare detailed methodology of proposed repairs/strengthening
- Collate the data to prepare estimated cost of the repair program
- Photograph of major distress
B. Carrying out Non-Destructive Test (NDT) on concrete structure :
NDT include the following :
- Rebound Hammer Test – To identify the surface characteristics with guidelines on strength.
- Ultra-Pulse Velocity Test – To assess the strength of concrete, honeycoming and the cracking pattern, etc.
- Half-Cell Potentiometer Test – To observe the initiation process of corrosion.
- Carbonation Test – To observe the initiation process of carbonation
- Core Test – To assess the present strength of concrete
C. Report Format :
The report shall be presented to you in the formate mentioned below :
- Introduction
- Methodolgy
- Observations including distress mapping as required
- Recommendations and conclusions
- Bill of quantity
- Exhibits
- NDT results and analysis of the result
Tenders are invited on behalf of the client
- Preparing tender document including technical specifications and contract agreement for contractors.
- Evaluating tender and company profile for technical bid
- Preparation of comparative statement for commercial bid
- Site visit to select the most competitive bidder
- Proper supervision on site by experienced supervisor
- Ensuring no diagressing of technical specification during execution
- Co-ordination between contractor and society for ensuring timely completion of the work within the budget
- Site visit by project engineer as per requirement
- Material checking and testing, quality control and measurement checking
- Provide technical solutions as required on site
- Defects list to be rectified by the contractor
- Monitoring the progress of work and bar chart for its timely completion
- Reconciliation and certify the bills after scrutiny
Specific structural audit is required for special problems like:
- Evaluation for an extension of floors
- Evaluation for change in use
- Evaluation for rooftop solar panel supports, tower installation and hoarding supports
- Evaluation for increase in EOT crane capacity
- Evaluation for damage due to fire
The broad scope of work includes:
- Viusal inspection
- Non-Destructive Testing
- Preparation of structural drawings using rebar mapping
- Full blown 3-D Finite Element Analysis of the structure
- Design checking of structural members for codal requirement
- Divise retroffiting methods for seismic loading
- Collate data and prepare repair estimate
We are among very few consultants in Mumbai to provide this unique service. The broad scope of work includes:
- Preparation of 3D model of the structure from the available structural/architectural drawings.
- Assigning properties to the members and ascertaining the in-situ strength of the concrete by testing core samples (depending upon the structure but minimum 5).
- Carrying out structural analysis of the model.
- Identifying members with reduced strength and requiring retrofitting.
- Designing the retrofitting scheme for the members.
- Preparing detailed report
Retrofitting scheme:
Retrofitting requires indepth design knowledge and conversance of the design codes. There is a thin line between repairing a distressed RCC member and retrofitting a distressed RCC member. Repairing is a first step to retrofitting a member. Repairing makes good the distressed RCC member by treating the member for the loose portion, thereby restoring it lost original strength, which is limited to the distressed portion. However, repairing doesn’t further increase the strength of the member. The strength of RCC members reduces over a period of time due to age, improper maintenance, etc. or is inadequate for increased loading due to an extension of a floor, change of use, change in codes, etc. This loss and/or reduced strength has to be enhanced by retrofitting. There are different ways of retrofitting:
- Fiber wrapping for shear and flexure defects in beams
- Fiber wrapping in columns for inadequate load carrying capacity
- Steel jacketing for shear and flexure defects in beams
- Concrete jacketing for beams and columns
- Designing the retrofitting scheme for the members.
- Steel jacketing for columns
It is especially important to identify the optimum retrofitting solution for a particular RCC member as every member needs different retrofitting solution. Retrofitting is also required to strengthen the building for seismic loading as per CPWD manual.
