New methodology for assessment of reinforced concrete structures with non-destructive testing

L Ebensperger,J.P Donoso

doi:10.4067/s0718-50732021000200233

Abstract

A Structures Assessment Methodology is presented, complementary to the Visual Inspection, which allows, through on-site non-destructive testing (NDT), to deliver a comprehensive quantitative evaluation of the "Structural Health" of the different elements. This allows essential information to adjust maintenance cycles or make timely based decisions in critical situations to guarantee future performance. The proposed methodology considers the execution of NDT to determine the state of the reinforcement, the characteristics of the concrete cover, and the presence of cracks. By extracting smaller size (1") cores, the ingress of carbonation or chlorides is determined. The results measured on-site are weighted to determine a Deterioration Index, DI. The aggressiveness of the environment is included through an Environmental Exposure Index, EEI. The incorporation of the results to the CTK-ConDiagÂ® Model allows the combination of both indices, obtaining a Structure Global Deterioration Level SGDL, which measures the degree of damage determined at six levels. The proposed methodology is presented with the results of the study carried out on two specific bridges in Chile under different climatic conditions.

Highlights

Se presenta una metodología de Diagnóstico de Estructuras complementaria a la Inspección Visual, que permite mediante la ejecución in-situ de ensayos nodestructivos (END), entregar como resultado una evaluación cuantitativa integral del “Estado de Salud” de los distintos elementos
In many cases, this visual inspection does not provide enough parameters to accurately determine in which stage of its "Service Life" the structure is, making it difficult to decide on the appropriate repair or mitigation measures required for each case. (Figure 1) schematically illustrates the concepts associated with the Performance, Serviceability and Service Life and Residual Life of a structure and the necessary periods to perform maintenance
In order to contribute with a new Assessment Methodology of Reinforced Concrete Bridges, a gap has been detected between the current inspection levels

Summary

Introduction

Se presenta una metodología de Diagnóstico de Estructuras complementaria a la Inspección Visual, que permite mediante la ejecución in-situ de ensayos nodestructivos (END), entregar como resultado una evaluación cuantitativa integral del “Estado de Salud” de los distintos elementos. Los resultados medidos en terreno son ponderados para determinar un Índice de Deterioro ID. Los aspectos de agresividad del ambiente son considerados mediante un Índice de Exposición Ambiental IEA. In Chile, road infrastructure is essential for the connectivity of the country. For this reason, more than 6,000 reinforced concrete bridges are part of this network. In order to contribute with a new Assessment Methodology of Reinforced Concrete Bridges, a gap has been detected between the current inspection levels. The recent technological development in the area of NDT allows access to a large offer from a technical point of view and accuracy in the reliability of the data delivered by the equipment

Methods

Discussion

Conclusion