An electronic monograph

Modeling and Measuring the Structure and Properties of Concrete Materials

Description

Over the last 20 years, computational materials science has developed as a scientific discipline, powered by the revolutionary advances made in computer processing speed and memory capacity. The main application of this discipline has been to random materials, where analytical approaches are inadequate. This applies especially to concrete, which is a random material over length scales ranging from nanometers to meters. Along with this modeling growth has come an increased emphasis on the careful experimental measurement of concrete microstructure and properties, based on fundamental materials science.
This monograph is an attempt to summarize what has been developed thus far in the computational materials science of concrete. Relevant experimental measurements of microstructure and properties are also covered. The monograph focuses on the work done by us, or in collaboration with us at NIST, as this has probably been the main (and almost the only) center for the computer modeling of the microstructure and properties of concrete since the 1990's. The situation as of 2003 is improving, with the growth of the industrial partners in the Virtual Cement and Concrete Testing Laboratory consortium (see button on main monograph page), and growing realization that experimental measurements of fundamental quantities promote the development and improvement of computer-based models, which in turn help to predict and interpret experiments.

Many people outside of NIST have contributed to the work. The main source of text in this monograph is published papers. We have kept the original authors' heading of each paper so that appropriate credit is given to the various contributors both within and outside NIST.

How to use this monograph

For someone working in concrete, and is new to the modeling of concrete, we suggest that you start with the introduction and work straight through the monograph, Part I. There are some who work with other materials and don't know much about concrete, and who are actually more interested in the modeling techniques themselves. For this category of people, we have included an appendix (Appendix I-1) that will introduce non-cement researchers to concrete and summarize the main modeling results. This is also an appropriate review for people working in the field of cement-based materials. Part II of the monograph focuses more on general, non-concrete applications of models.
The main way the text is linked together is via the references in each section. The references that are included in this monograph have been made into links, which will lead to the appropriate section. Also, each chapter is linked back to the table of contents, and the following and preceding chapter. In each section, there are links going forward and backward to the next part of the section, as well as links going back to the chapter itself or again the table of contents. There is also a search engine (electronic index) that will search the monograph for key words.

In each chapter, for most sections there is a statement of approximately how many pages of text and how many bytes of figures there are for that entry.

Acknowledgments

Much of this work has been done in collaboration with researchers involved in the Center for Advanced Cement-Based Materials (ACBM), which is headquartered at Northwestern University. ACBM is a consortium of Northwestern University, the University of Illinois at Champaign-Urbana, Purdue University, the University of Michigan, and NIST. We also thank the NIST Building and Fire Research Laboratory, along with its former director, Dr. Richard Wright (retired), Dr. Geoffrey Frohnsdorff (deceased), and Dr. James Clifton (deceased), for their long-term support of this modeling effort. We also acknowledge the HYPERCON: Prediction and Optimization of Concrete Performance program for funding the continuing development of this electronic monograph and some of the modeling program. Other sponsors include ACBM, the industrial members of the Virtual Cement and Concrete Testing Laboratory, NRC, and FHWA.

Recent Revisions

Part I: Cement-Based Materials

Other NIST authors who have contributed to Part I

Introduction

Concrete rheology

Cement and concrete characterization

Microstructure development of cement paste phases

Cement paste percolation, transport, and elastic properties

Mortar and concrete microstructure

Transport, elastic, and thermal properties of mortar and concrete

Curing and autogenous shrinkage of concrete

Degradation of mortar and concrete

Aggregates: Shape and properties

Appendix I-1: Summary of concrete and concrete modeling for non-cement-based materials researchers

Appendix I-2: CEMHYD3D: A three dimensional cement hydration and microstructure development modeling package. Version 3.0 (06/05) and Version 2.0 (4/00)

Appendix I-3: User's guide to the educational virtual cement and concrete testing laboratory (eVCCTL). Version 2.0 (10/10)

Part II: Fire-Resistive Materials

Other NIST authors who have contributed to Part II

Microstructure

Thermophysical properties

Adhesion properties

Part III: General Random Porous Materials

Other NIST authors who have contributed to Part III

Introduction

Finite difference and finite element programs for random materials

Percolation theory

Microstructure development and probes

Conductivity

Fluid flow

Elastic Properties

Appendix III-1: Digital images of porous materials and computer modeling: Description of a digital toolkit