Authors : Cheruiyot K. Joab; Kivya Mark; Omuse Giles; Kiptum Clement; Kevin Maraka

Volume/Issue : Volume 11 - 2026, Issue 5 - May

Google Scholar : https://tinyurl.com/yjr72akj

Scribd : https://tinyurl.com/475f6t7c

DOI : https://doi.org/10.38124/ijisrt/26May331

Note : A published paper may take 4-5 working days from the publication date to appear in PlumX Metrics, Semantic Scholar, and ResearchGate.

Abstract : Structural integrity assessment is central to ensuring the safety and serviceability of reinforced concrete (RC) buildings, especially those that have experienced prolonged exposure or construction delays. This case study evaluates the condition of an existing RC structure using a combination of non-destructive tests (NDTs), namely the Schmidt/Rebound Hammer Test, Ultrasonic Pulse Velocity Test (UPV), Resistivity Test, and Carbonation Test. The objective was to measure on-site the compressive strength, material homogeneity, and the likelihood of reinforcement corrosion without damaging the structure. The methodology began with a comprehensive visual inspection to identify surface defects, followed by the application of NDT to quantify concrete quality and durability. The results showed that the average compressive strength of concrete ranged between 22–33 N/mm², indicating moderate-to-good quality material. UPV results (3.0–4.0 km/s) confirmed satisfactory internal homogeneity, while resistivity values above 25 kΩ·cm suggested minimal corrosion risk, except in localized zones where values dropped below 5 kΩ·cm, indicating active corrosion potential. Carbonation depths were limited to 1–3 mm, far below reinforcement cover, confirming adequate alkaline protection. Overall, the study found that the structure remains structurally sound and suitable for rehabilitation rather than demolition. The results demonstrate that integrating multiple NDT techniques significantly enhances diagnostic accuracy, offering a non-invasive, economical, and reliable means for assessing existing concrete structures. This approach is particularly relevant for developing regions, where sustainable rehabilitation of incomplete or aging structures is essential for public safety and resource efficiency.

Keywords : Non-Destructive Tests; Visual Inspection; Schmidt Hammer Test; Carbonation Test; Ultrasonic Impulse Velocity Test; Resistivity Test.

References :

1. Rao, P. & Bandyopadhyay, S. (2025) ‘Review of hybrid non-destructive techniques for aging concrete infrastructure’, Journal of Civil Structural Health Monitoring, 15(3), pp. 411-428. doi:10.1007/s13349-025-00728-1. (Note: placeholder reference) Shendkar, M.R., Tantri, A. & Rao, A.U. (2025) ‘Seismic Evaluation and Retrofit of Reinforced Concrete Structures’, Journal of Infrastructure Preservation and Resilience, 6, Article 2. doi:10.1186/s43065-024-00114-y. SpringerOpen
2. Preethi Venkatesh, Mallika Alapati(2017). ‘Condition assessment of existing concrete building using non-destructive testing methods for effective repair and restoration - a case study.’  https://doi.org/10.28991/CEJ-030919.
3. Pinta Astuti, Rahmita Sari Rafdinal, Daisuke Yamamoto, Hidenori Hamada; ‘Non-destructive test methods on deteriorated reinforced concrete structures.’ AIP Conf. Proc. 18 June 2025; 3234 (1): 030007. https://doi.org/10.1063/5.0258511
4. Mwangi (2024). [As cited in regional stalled building assessments; related East African NDT studies].
5. Akduman, Seda & Öztürk, Hakan. (2024). Effect of reinforcement corrosion on structural behavior in reinforced concrete structures according to initiation and propagation periods. Buildings. 14. 4026. 10.3390/buildings14124026.
6. Herki, Bengin & Khatib, Jamal & Ramadhan, Zina & Hamadameen, Banaz. (2023). ‘Condition assessment of building concrete structures using NDTs - case study.’ International Conference on Recent Academic Studies. 1. 158-171. 10.59287/icras.690.
7. Dadras, Armin & Ghaderiaram, Aliakbar & Schlangen, Erik & Fotouhi, Mohammad. (2023). ‘A review on non-destructive evaluation of construction materials and structures using magnetic sensors.’ Construction and Building Materials. 397. 10.1016/j.conbuildmat.2023.132460.