The Modelling Of Microstructure And Its Potential For Studying Transport Properties And Durability

From July 10th through July 13th, 1994, an informal workshop co-organized by RILEM committees 116-PCD and 123-MME was held at Saint-Remy-Ies Chevreuse, France, and attended by 38 delegates from 16 countries. Twenty-nine papers were presented, converging the general subjects of modelling micro structures and predicting durability of concrete and other cement-based materials. A short summary follows: G. M. Idom's paper entitled "Modelling Research for Concrete Engineering" serves as an introduction to the workshop, presenting an overview of modelling research with the conelusion that the broad practica1 objective is to produce high-quality concrete. This means that many characteristics, ranging from rheology to alkali-silica reaction, must be modelled. In other words, the system must be understood. Idom's paper sets the stage for papers in two general areas: 1) models and 2) transport properties. After this, abrief survey of the develop ment of microstructurally-based models is presented. A elose relationship between computer power and speed is suggested. The first group of papers on models covers the subjects of scale and resolution. Most models define and predict characteristics of the pore system, which range in scale from nanometer to millimeter. Various types ofnetworks are proposed in these papers. A good microstructural model must describe the pores and other phases at ascale appropriate to the properties that the model predicts. Also, a good model should be based on fundamental knowledge. In the case of cement-based materials, the important properties may depend on the microstructure, especially the porosity, at several scales.

Transport Properties of Concrete: Modelling the Durability of Structures, Second Edition, covers how to measure transport properties and use the results to model performance. The transport properties of concrete and measurements of the ability of ions and fluids to move through the material. These properties largely determine the durability of concrete and of steel embedded within it, as well as the effectiveness of structures such as waste containment barriers. The book provides a comprehensive examination of the subject and will be of use to all concerned with the durability and effectiveness of concrete structures. Includes a new chapter on modelling the durability of concrete structures showing how both diffusion and pressure driven flow should be included Covers the problems that occur when carrying out transport tests on concrete incorporating both traditional and newer cement replacements Shows how properties such as permeabilty which are needed for modelling may be derived from in situ tests on structures

Condition assessment and characterization of materials and structures by means of nondestructive testing (NDT) methods is a priority need around the world to meet the challenges associated with the durability, maintenance, rehabilitation, retrofitting, renewal and health monitoring of new and existing infrastructures including historic monuments. Numerous NDT methods that make use of certain components of the electromagnetic and acoustic spectrum are currently in use to this effect with various levels of success and there is an intensive worldwide research effort aimed at improving the existing methods and developing new ones. The knowledge and information compiled in this book captures the current state of the art in NDT methods and their application to civil and other engineering materials and structures. Critical reviews and advanced interdisciplinary discussions by world-renowned researchers point to the capabilities and limitations of the currently used NDT methods and shed light on current and future research directions to overcome the challenges in their development and practical use. In this respect, the contents of this book will equally benefit practicing engineers and researchers who take part in characterization, assessment and health monitoring of materials and structures.

ICE Handbook of Concrete Durability, second edition is a comprehensive practical reference for professionals involved in design and maintenance of concrete structures of all types. It is an invaluable guide for construction professionals, including design engineers, consultants and contractors, as well as postgraduate students.