PSI - Issue 52

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Rakesh Katam et al. / Procedia Structural Integrity 52 (2024) 72–88 Rakesh Katam/ Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 2. Flow of structural assessment.

2. Literature Review Structures deteriorate, with time and their severity depends on their exposure to loads and physical conditions. Even though there are numerous factors that might cause a structure to be distressed, some of which include poor maintenance, construction flaws, and other environmental or operational load. Periodic maintenance is required to determine the current health of the structures by conducting a few testing procedures like employing NDT to prevent the buildings from sudden failures. Dey et al. (2020) worked on the degradation of the existing structure due to ageing using two different NDT methods, Rebound Hammer (RH) and Ultrasonic Pulse Velocity (UPV). Lin et al. (2016) worked with several samples and various mixed proportions, to assess the compressive strength of the concrete using UPV. The ageing of concrete and various mixed proportions is determined experimentally in their work and found that UPV shows less accuracy in wet samples compared to dry samples. Kumavat et al. (2021) worked on an experimental investigation of RH and the B-Proceq curve's influencing variables, including cement type, water-cement ratio, carbonation effects, fire exposure, compaction, and curing conditions. In the context of this, it was discovered through laboratory experimentation that the average rebound index is time-dependent and cannot be relied on a single function. Gupta & Gupta (2021) worked on a reinforced concrete structure to assess the strength and durability of the components in the structure before reliability analysis or probably damaged region identification can be done. NDT values aid in the knowledge of the building's material qualities and local damage assessment, as well as the development of a numerical model for the structure's overall state. Naddaf et al. (2016) worked on a variety of retrofitting techniques for the buildings, which required the renovation of five floors for salt-affected buildings considering 50% corrosion. To determine the current load-carrying capacity of the building, the numerical model was developed using ETABS. Following a thorough analysis of the building, two practical solutions were offered to reduce repair costs and provide the utmost safety, which are steel plate jacketing and reinforced concrete jacketing. Thus, solutions increased safety and reduced the cost by 70%. Zahra et al. (2014) examined a 40-year-old RCC frame structure by using NDT methods to evaluate the condition of the existing structure, and the results were used to create a 3D numerical model to understand the current load-carrying capacity and structural behavior. As a result, it is advised that the building be strengthened to extend the top floor. Gupta et al. (2021) studied and examined how technological improvements have widened the scope of NDT and demonstrated that NDT is not restricted to anomaly detection. Even though these advancements have improved NDT, this study emphasizes that these procedures are primarily manual and heavily reliant on inspectors' knowledge and experience, allowing space for errors. The study also examines the major obstacles and prospects in the field of NDT. After looking at different NDT and their advantages two tests RH and UPV are more suitable for the prediction of concrete quality and strength. Hamidian et al. (2012) work on two different NDT methods to collect the material properties of "in place" specimens without destroying them and to monitor structural health. When UPV and RH tests are utilized together, a combined test technique for health assessment is created, with a good correlation between the