Reinforcement corrosion has been widely reported in the literature over the last two to three decades. It is one of the major durability problems, mainly when the rebar in the concrete is exposed to the chlorides either contributed from the concrete ingredients or penetrated from the surrounding chloride-bearing environment. Carbonation of concrete or penetration of acidic gases into the concrete, are the other causes of reinforcement corrosion. Besides these there are few more factors, some related to the concrete quality, such as w/c ratio, cement content, impurities in the concrete ingredients, presence of surface cracks, etc. and others related to the external environment, such as moisture, oxygen, humidity, temperature, bacterial attack, stray currents, etc., which affect reinforcement corrosion. The assessment of the causes and extent of corrosion is carried out using various electrochemical techniques. Prediction of the remaining service life of a corroding RC structure is done with the help of empirical models and experimental methods. In this paper a review is presented on the mechanism of reinforcement corrosion, techniques utilized to monitor reinforcement corrosion and methodologies that are utilized for the prediction of remaining service life of structures.

https://faculty.kfupm.edu.sa/ce/shamsad/abstracts/jp/shamsad_jp06.pdf

Reinforcement corrosion in concrete structures, its monitoring and service life prediction - A review

Modelling ground penetrating radar by GprMax

This paper reviews the state of non-destructive testing (NDT) methods as applied to the civil engineering industry in the Millennium Year, 2000. The basic principles of NDT methods are described with particular reference to the five major factors that influence the success of a survey: depth of penetration, vertical and lateral resolution, contrast in physical properties, signal to noise ratio and existing information about the structure. The main NDT methods used in engineering investigations are discussed and illustrated with brief case histories from the literature. The integration of NDT surveys into the investigation of structures is described. The underlying reasons why NDT methods are perceived as ‘not working’ by the structural engineer are identified as: a lack of understanding of variability of both the construction materials used and NDT methods themselves.

Review of NDT methods in the assessment of concrete and masonry structures

The evolution of the structural behavior in reinforced concrete beams subjected to reinforcement corrosion is studied here, by developing a suitable numerical procedure, which is validated by comparison with available test data. There are two objectives of this study: The understanding of the many aspects of the progressive damage in an existing structure (cracking and crushing, bar yielding, bond failure), and the assessment of the actual safety level. Nonlinear finite element analysis is used; the effects of corrosion are modeled by reducing the geometry of the finite elements representing separately the steel bars and the concrete, and by modifying the constitutive laws of the materials (steel and concrete) and of their interface (bond). Both the service and ultimate limit states are studied, showing the importance of the following phenomena: (1) Stiffness decay because of impaired tension stiffening, (2) crack pattern evolution accompanied by enhanced shear effects, (3) strength deterioration in bendi...

Structural Assessment of Corroded Reinforced Concrete Beams: Modeling Guidelines

Utilization and efficiency of ground granulated blast furnace slag on concrete properties – A review

The principal aim of this book is to provide non-specialist engineers responsible for the planning of test programmes with an overview of the subject, to guide them in their planning, and to advise them in the selection of the most suitable testing method for a particular problem. All the major testing methods used throughout the world are discussed together with their advantages and disadvantages, while newer testing procedures are assessed as to their future significance. The book contains chapters on: planning and interpretation of in situ testing; surface hardness methods; ultrasonic methods; penetration resistance, pull-out, pull-off and break-off methods; cores; load testing; miscellaneous test methods for properties other than strength (magnetic methods, radioactive methods, nuclear methods, electrical methods, microwave absorption, holographic and acoustic emission techniques, infrared thermography, photoelastic methods, tests for permeability and absorption, pulse echo techniques, abrasion resistance and integrity testing); chemical testing and allied techniques are also discussed. Five case studies are appended together with an extensive bibliography. (TRRL)

The Testing of Concrete in Structures

Chapter One: Planning and interpretation of in-situ testing. Chapter Two: Surface hardness methods. Chapter Three: Ultrasonic pulse velocity methods. Chapter Four: Partially destructive strength tests. Chapter Five: Cores. Chapter Six: Load testing and monitoring. Chapter Seven: Durability tests. Chapter Eight: Performance and integrity tests. Chapter Nine: Chemical testing and allied techniques. Appendix A, B, C. References. Index.

testing of concrete in structures

Strength development of mortars containing ground granulated blast-furnace slag: Effect of curing temperature and determination of apparent activation energies

Sub-surface radar is becoming increasingly popular as an inspection method Interpretation can be enhanced if uncertainties about the dielectric properties of the concretes under investigation are removed The need for reliable data to identify possible variations of the dielectric properties of different concrete mixes and their condition on site has led to a systematic laboratory based experimental programme under the auspices of a major European Commission (Brite-Euram III Framework 4) funded project Some key results from this recently completed work are presented in this paper with practical implications related to field surveys of structural concrete

John H. Bungey

Papers

The Testing of Concrete in Structures

testing of concrete in structures

Strength development of mortars containing ground granulated blast-furnace slag: Effect of curing temperature and determination of apparent activation energies

Dielectric properties of concrete and their influence on radar testing

Using compression wave ultrasonic transducers to measure the velocity of surface waves and hence determine dynamic modulus of elasticity for concrete