brief overview of research: cement and...

MIT Industrial Liaison Program January 2010 | Page 2

Brief Overview of Research Cement and Concrete This survey by MITs Industrial Liaison Program identifies MIT selected research in the area of cement and concrete from 2008 through January 2010 For more information please contact MITrsquos Industrial Liaison Program at +1-617-253-2691

CEMENT AND CONCRETE RESEARCH INITIATIVES PROJECTS 3

CONCRETE SUSTAINABILITY HUB (CSH) 3 Concrete Materials Science Platform 3 Concrete Building Technology Platform 3 Concrete Econometrics Platform of Sustainable Development 4

ATOMISTIC SIMULATION OF NANOCOMPOSITES 4 COMPARISON OF POINTED VS CIRCULAR ARCHES 4 DYNAMIC ANALYSIS OF UNREINFORCED MASONRY STRUCTURES 4

Thrust-Line Tilt Analysis of Masonry Structures 5 Thrust Network Analysis Exploring 3-D Equilibrium 5

INFRASTRUCTURE SCIENCE AND TECHNOLOGY GROUP (IST) 5 Remote Detection of Damages in FRP-retrofitted Concrete Structures using Acoustic-Laser Vibrometry 6 Paper ldquoA Fracture-based model for FRP debonding in strengthened beamsrdquo 6 Paper ldquoFar-field Radar NDT Technique for Detecting GFRP Debonding from Concreterdquo 6

DEVELOPMENT OF THE CONCEPT OF DEFECT CRITICALITY 7 INTEGRITY OF PRECRACKED REINFORCED CONCRETE RETROFITTED WITH COMPOSITE LAMINATES 7 MATERIAL PROPERTY CHARACTERIZATION OF CONCRETE EPOXY SYSTEM 8 ATOMISTIC SIMULATION OF INTERFACE FRACTURE IN BILAYER MATERIAL SYSTEMS 8 ATOMISTIC SIMULATION OF CHLORIDE ION BINDING ON THE SURFACE OF CALCIUM-SILICATE-HYDRATE (C-S-H) 8

RELATED NEWS 9

NEW METHODS ARE CHANGING OLD MATERIALS 9 MIT ENGINEERS FIND WAY TO SLOW CONCRETE CREEP TO A CRAWL 12 ldquoGATHERING CONCRETE EVIDENCE MIT CLASS EXPLORES CONTROVERSIAL PYRAMID THEORY WITH SCALE

MODELrdquo 12 CEMENTrsquoS BASIC MOLECULAR STRUCTURE FINALLY DECODED 13


CEMENT AND CONCRETE RESEARCH INITIATIVES PROJECTS

CONCRETE SUSTAINABILITY HUB (CSH) 2009 Director Prof Franz-Josef Ulm httpceemiteduulm Co-Director Prof John A Ochsendorf httpceemiteduochsendorf Executive Director Hamish M Jennings httpceemitedujennings httpwebmiteducshub httpwebmiteducshubnewsnewshtml httpwebmiteducshubresearchprojectshtml More concrete is produced than any other synthetic material on Earth In the foreseeable future there is no other material that can replace concrete to meet our societies legitimate needs for housing shelter schools infrastructure etc Concrete is produced from abundant raw materials locally available almost everywhere on earth It is an inexpensive construction material with a relatively small environmental footprint but its attractive properties have lead to massive use that contributes approximately 5 of global CO2 production On the other hand emerging breakthroughs in concrete science and engineering hold the promise that concrete can be part of the solution of contributing to a sustainable development that encompasses economic growth social progress while minimizing the ecological footprint This requires a holistic approach in which progress in concrete science seamlessly feeds into innovative structural concrete engineering applications ranging from concrete pavement solutions to wall systems whose impact on sustainable development are evaluated with advanced environmental-econometric impact studies This is the focus of the Concrete Sustainability Hub (CSH) With this focus in mind an exceptional team of dedicated interdisciplinary faculty from three different schools within MIT School of Engineering School of Architecture and Planning and the Sloan School of Management are participating

Concrete Materials Science Platform One of the most critical issues for a sustainable development of concrete as the backbone material for infrastructure and housing is to address the CO2 footprint of concrete materials We propose a new way to address this issue one that is based on a shift of paradigm that will transform the way cement based materials are designed and characterized by industry for green concrete applications The basis of our paradigm-shifting R amp D is the first atomistic-scale computational model of this complex material from which we will predict new structures and improved properties that will revolutionize how cement is designed slash CO2 emissions and enable US leadership in future energy-related cement technologies To drive this idea from discovery to technology MIT scientists and engineers will leverage collaborations and industrial partnerships of the Concrete Sustainability Hub with Federal Laboratory experts and computational resources

Concrete Building Technology Platform To further drive discovery towards implementation we shall explore new materials-structural solutions for a large range of concrete engineering applications such as concrete pavements wall systems etc The focus of the concrete building technology unit is the development of aggregate models for such systems that are able to translate progress on the concrete science front (materials properties reduced environmental footprint) into added value performance criteria which include structural and life-span performance life-cycle analysis and CO2 balance investigations


Concrete Econometrics Platform of Sustainable Development Ultimately meeting the challenge of sustainable development requires overcoming the valleys of death of technology implementation The improvements in technology and operation needed to allow sustainable development of cement and concrete industry depend crucially on the delivery to manufacturers state and federal administrators and regulators of robust results incorporating improved understanding of the processes and interactions that determine the environmental impact The CSH concrete econometrics unit will dedicate research to assessing the impact of concrete science and building technology advances on energy and climate policies and vice versa This will involve modeling the demand for and supply of energy and carbon pricing systems technology assessment simulation and assessment of the impact of energy and climate policies on the concrete industry

ATOMISTIC SIMULATION OF NANOCOMPOSITES 2008 Prof Franz-Josef Ulm Department of Civil and Environmental Engineering httpceemiteduulm Atomistic simulation of nanocomposites can provide deep insight into the smallest building block of materials The aim of our research is to examine material behavior systematically at the nano level and correlate properties to higher scales We focus on calcium silicate hydrate (C-S-H) a hydrated nanocomposite known to be the structure of cement paste materials The molecular dynamics method and ab initio calculations are used to simulate and predict the mechanical properties of C-S-H

COMPARISON OF POINTED VS CIRCULAR ARCHES 2008 Prof John A Ochsendorf Masonry Research Group httpceemiteduochsendorf httpwebmitedumasonryprojectshtml In Gothic cathedrals the use of pointed arches is widespread because of the decreased thrust compared to the circular arch While this fact is widely acknowledged and accepted there has been little theory developed to determine exactly the different behavior of the two arches This research develops the comparison between the circular and the pointed arches in terms of geometrical dimensions weight maximum and minimum thrust maximum point load at the crown and the haunches and collapse values due to support movements Using limit analysis a parametric study of whole and half arches has been performed varying the angle of embrace the thickness and the eccentricity of the centers of the arches A theory using graphical and numerical codes was tested to predict when and where failure occurs and a series of experiments on these arches made of small-scale concrete blocks has been conducted Analyzing and comparing the experimental results with the proposed theory has shown good agreement

DYNAMIC ANALYSIS OF UNREINFORCED MASONRY STRUCTURES 2008 Prof John A Ochsendorf Masonry Research Group httpceemiteduochsendorf The primary focus of this research is to develop tools to assess the safety of unreinforced masonry structures subjected to dynamic loading Analysis tools which are currently being developed andor evaluated involve analytical modeling discrete element modeling and finite element modeling The accuracy of these techniques is being verified experimentally Analysis tools are also currently being applied to evaluate the condition of existing structures whose safety is in question


More at httpwebmitedumasonrymdejongindexhtml

Thrust-Line Tilt Analysis of Masonry Structures Prof John A Ochsendorf Masonry Research Group httpceemiteduochsendorf A first-order assessment of structures subjected to earthquake loading can be achieved by applying a static horizontal force that is some portion of the structurersquos weight This horizontal force (or acceleration) can be effectively simulated by tilting the base on which the structure rests This concept along with thrust-line analysis can be used to determine the minimum horizontal acceleration that a masonry structure can withstand While this could be done numerically the graphical method provides additional clarity through visualization of the resultshellip See httpwebmitedumasonryinteractiveThrust

Thrust Network Analysis Exploring 3-D Equilibrium 2009 Prof John A Ochsendorf Masonry Research Group httpceemiteduochsendorf Thrust Network Analysis is a new methodology for generating compression-only vaulted surfaces and networks The method finds possible funicular solutions under gravitational loading within a defined envelope Using projective geometry duality theory and linear optimization it provides a graphical and intuitive method adopting the same advantages of techniques such as graphic statics but offering a viable extension to fully three-dimensional problems The proposed method is applicable for the analysis of vaulted historical structures specifically in unreinforced masonry as well as the design of new vaulted structures This paper introduces the method and shows examples of applications in both fields

INFRASTRUCTURE SCIENCE AND TECHNOLOGY GROUP (IST) Prof Oral Buyukozturk Department of Civil and Environmental Engineering httpceemitedubuyukozturk httpwebmiteduistgroupistindexhtml The general goal of the IST Group is to contribute to the science and engineering knowledge base for the advancement of understanding assessment and effective renewal of civil infrastructure systems The IST Group aims at the development of new scientific and engineering knowledge in the following key areas Deterioration science examines conditions and processes by which materials and structures breakdown overtime Our understanding needs to be improved as a basis for designing building and maintaining structures that are durable safe and environmentally sound Assessment technologies allow us to assess the existing mechanical condition of materials and structures Research in this area is needed to develop effective nondestructive evaluation techniques and improved sensor technologies Renewal engineering aims at the extension of the life of physical infrastructure systems and components and at the enhancement of load capacities of these systems to meet the increased demands imposed on them We focus our research in this aspect on developing and implementing effective repair and strengthening methods using high performance advanced composite materials


Remote Detection of Damages in FRP-retrofitted Concrete Structures using Acoustic-Laser Vibrometry Prof Oral Buyukozturk Department of Civil and Environmental Engineering Infrastructure Science and Technology Group httpceemitedubuyukozturk httpwebmiteduistgroupistresearchindexhtml Damage in FRP- concrete Systems Fiber-reinforced polymer (FRP) composites are being used to retrofit or strengthen existing concrete structural members Nonetheless subsequent damage to the repaired systems can occur in form of interface debonding and concrete cracking underneath FRP layer These invisible damages are caused by environmental exposure recurring seismic event or insufficient workmanship during repair process It has been recently identified that a FRP-retrofitted concrete beams and columns could appear safe without showing any sign of substantial damage yet containing a severely deteriorated concrete and debonded FRP composites Therefore an efficient NDT technique is required for timely damage detectionhellip More at httpwebmiteduistgroupistresearchacoustic_ndthtml

Paper ldquoA Fracture-based model for FRP debonding in strengthened beamsrdquo by Gunes O Buyukozturk O and Karaca E (2009) Engineering Fracture Mechanics 76 (12) p 1897-1909 Paper at httpwebmiteduistgroupistdocuments2009_A20fracture-based_model_for_FRP_debonding_in_strengthened_beamspdf Prof Oral Buyukozturk Department of Civil and Environmental Engineering Infrastructure Science and Technology Group httpceemitedubuyukozturk httpwebmiteduistgroupistresearchindexhtml httpwebmiteduistgroupistresearchprojectshtm This paper presents an experimental and analytical research study aimed at understanding and modeling of debonding failures in fiber reinforced polymer (FRP) strengthened reinforced concrete (RC) beams The experimental program investigated debonding failure modes and mechanisms in beams strengthened in shear andor flexure and tested under monotonic loading A newly developed fracture mechanics based model considers the global energy balance of the system and predicts the FRP debonding failure load by characterizing the dominant mechanisms of energy dissipation during debonding Validation of the model is performed using experimental data from several independent research studies and a design procedure is outlined copy 2009 Elsevier Ltd

Paper ldquoFar-field Radar NDT Technique for Detecting GFRP Debonding from Concreterdquo O Buyukozturk and T-Y Yu (2009) Construction and Building Materials 23 1678-1689 Paper at httpwebmiteduistgroupistdocuments2009_FAR_NDT_TY_amp_OBpdf Prof Oral Buyukozturk Department of Civil and Environmental Engineering Infrastructure Science and Technology Group httpceemitedubuyukozturk httpwebmiteduistgroupistresearchindexhtml httpwebmiteduistgroupistresearchprojectshtm


A radar nondestructive testing (NDT) technique using an airborne horn antenna operating in the far-field condition is developed for detecting damages such as debonding and concrete cracking in glass fiber reinforced polymer (GFRP)-wrapped concrete columns The far-field airborne radar (FAR) NDT technique is advantageous for distant measurement in practical applications where contactnear-contact measurement becomes an issue In this technique the radar antenna operates in inverse synthetic aperture radar (ISAR) mode Laboratory measurements at the frequency range 8ndash18 GHz are made on artificially damaged GFRPndashconcrete specimens for a preliminary validation of this technique Collected frequencyndashangle measurements are further processed by the fast back-projection algorithm to render rangendashcross-range imagery for damage detection From the reported measurements and imaging results the proposed FAR NDT technique is conceptually validated the potential of this technique is shown in identifying defects and debonding in the GFRPndashconcrete interface regions of the concrete columns wrapped with these composite materials copy 2009 Elsevier Ltd

DEVELOPMENT OF THE CONCEPT OF DEFECT CRITICALITY 2008 Prof Oral Buyukozturk Department of Civil and Environmental Engineering Infrastructure Science and Technology Group httpceemitedubuyukozturk Extensive research has been conducted on the behavior of reinforced concrete columns with perfectly bonded fiber reinforced polymer (FRP) but little attention has been paid to the effect of possible initial defects on the structural performance of FRP-confined (or wrapped) concrete columns This project explores the effect of defect size on the integrity of FRP-confined concrete which governs the strength and deformability of the structural element The effect of initial defects on FRP-retrofitted concrete columns appears more complicated than that on FRP-retrofitted concrete beams In the FRP-retrofitted concrete beam propagation of a crack from an initial defect (pre-crack) at the interface may start as a local failure and be followed by a rapid global failure In a FRP-confined concrete column the propagation of the initial defect may not lead to global failure In general such a phenomenon alters the confining pressure provided by the FRP leading to stress redistribution and weakening of the structure Deformation behavior and final failure may greatly depend on defect criticality The objective of this research is to develop an in-depth mechanistic understanding of initial defect-induced fracture-through proper quantification-and to establish a link between local fracture and global failure in FRP-confined concrete This work will inform future design guideline development and life-cycle predictive capability

INTEGRITY OF PRECRACKED REINFORCED CONCRETE RETROFITTED WITH COMPOSITE LAMINATES Prof Oral Buyukozturk Department of Civil and Environmental Engineering httpceemitedubuyukozturk The objective of this proposed research is to provide a scientific basis for the underlying mechanisms of fracture and delamination of precracked reinforced concrete retrofitted using fiber-reinforced plastic (FRP) composite laminates and to develop design guidelines for efficient applications and safe engineering designs of these systems Laminated beams have been observed to fail through several mechanisms including yielding of the laminate crushing of the concrete and brittle fracture through delamination of the composite from the concrete Available experience has shown that fracture through delamination can occur at stress below material limits and under loads within normal service The emphasis of this study will be on delamination and its causes specifically in the presence of combined flexural and shear cracks in the retrofitted concrete beamhellip


More at httpglobalmiteduprojectsprojectintegrity-of-precracked-reinforced-concrete-retrofitted-with-composite-lami

MATERIAL PROPERTY CHARACTERIZATION OF CONCRETE EPOXY SYSTEM 2008 Prof Oral Buyukozturk Department of Civil and Environmental Engineering httpceemitedubuyukozturk Prof Markus J Buehler Department of Civil and Environmental Engineering httpceemitedubuehler Understanding the durability of concreteepoxy interfaces is becoming essential as the use of these systems in applications such as fiber reinforced polymer (FRP) strengthening and retrofitting of concrete structures is becoming increasingly popular Prior research in this area has indicated that moisture-affected debonding in an FRP-bonded concrete system is a complex phenomenon that may often involve a distinctive dry-to-wet debonding mode shift from material decohesion (concrete delamination) to interface separation (concreteepoxy interface) in which the concreteepoxy interface becomes the critical region of failure Such premature failures may occur regardless of the durability of individual constituent materials Thus the durability of FRP-bonded concrete is governed by the microstructure of the concreteepoxy interface as affected by moisture ingress In this project fracture toughness of concreteepoxy interfaces as affected by combinations of various degrees of moisture ingress and temperature levels is quantified For this purpose sandwich beam specimens containing concreteepoxy interfaces are tested and analyzed using the concepts of fracture mechanics

ATOMISTIC SIMULATION OF INTERFACE FRACTURE IN BILAYER MATERIAL SYSTEMS 2008 Prof Oral Buyukozturk Department of Civil and Environmental Engineering httpceemitedubuyukozturk Prof Markus J Buehler Department of Civil and Environmental Engineering httpceemitedubuehler Structural innovations often use multilayer material systems consisting of substrates and interfaces Interface performance and related failures in such layered systems can play a critical role in overall safety-especially when initial defects are present at the interfaces or in the substrates Fracture of the substrate materials or interfaces under various mechanical and environmental effects essentially involves atomistic deformation and breaking of chemical bonds between molecules Molecular dynamics (MD) simulation allows researchers and engineers to study the fracture process in multilayered material systems at the microscopic level The objective of this research is to use MD simulation to understand interface fracture behavior in bilayer material systems (ie crack initiation and propagation direction) and the effects of material and interface properties Motivated by the safety assessment of complex structural systems involving layers of different polymeric and concrete material properties this study is conducted in collaboration with Assistant Professor Markus J Buehler of the Laboratory of Atomistic and Molecular Mechanics Department of Civil and Environmental Engineering

ATOMISTIC SIMULATION OF CHLORIDE ION BINDING ON THE SURFACE OF CALCIUM-SILICATE-HYDRATE (C-S-H) 2009


Prof Bilge Yildiz Assistant Professor of Nuclear Science and Engineering Laboratory for Electrochemical Interfaces (Yildiz Research Group) httpwebmitedunsepeoplefacultyyildizhtml httpwebmiteduyildizgroupcshhtml hellipSpecifically our objective is to understand and control the transport and binding of chloride ion onto cement surface Chloride ion can induce localized corrosion on the alloys suggested as an inner barrier for nuclear waste confinement We are investigating the ability of cementitious materials to bind and stop the transport of chloride ion from the geological repository water onto the metal cask of the nuclear waste In our approach we will integrate a hierarchy of simulation methods to bridge length and time scales starting from the atomistic scale in order to predict the long term behavior of cement surface in this context More at httpwebmiteduyildizgroupcshhtml

RELATED NEWS

NEW METHODS ARE CHANGING OLD MATERIALS Computational approach to materials science could bring new properties even to familiar substances such as concrete and steel David L Chandler MIT News Office October 28 2009 httpwebmitedunewsoffice2009computational-materialshtml A company that makes steel for bearings used in heavy trucks had a big problem The trucks travel through harsh perilous environments such as Siberia and an unexpected bearing failure on a remote stretch could literally put the drivers life in danger Knowing how long the steel would hold up under those conditions was beyond their ability to predict experimentally so they turned to specialists at MIT Under applied weight steel deforms over time at an ever-increasing rate The exponent in the equations governing that process should be three according to scientific theory while experiments conducted over many decades always found it was really four or five says MIT materials scientist Krystyn Van Vliet Nobody could demonstrate the reason for this discrepancy mdash until now using new computational techniques Computers were able to solve the mystery by controlling all the variables and exploring every possible variation Van Vliet says The analysis had to be done at the level of the individual atoms in the material mdash exactly how carbon atoms are spaced among iron atoms in the material and how hydrogen atoms penetrate into that structure as the material degrades mdash in order to understand the behavior of the bulk material In laboratory experiments it would have been impossible to do in anyones lifetime she says Now using the analytical tools developed at MIT the company has embarked on a major program to analyze the materials degradation and find ways to improve it Thats just one example of how the field of materials science has profoundly changed in recent years From largely trial-and-error laboratory experiments the field has graduated to computational methods that use first principles of physics and chemistry to evaluate thousands of different variations in material composition The new approach called computational materials science is a powerful way of discovering new materials with desired properties mdash such as improved charge and discharge speeds for battery

MIT Industrial Liaison Program January 2010 | 0

materials mdash and of understanding and fine-tuning the properties of well-known long-used materials such as steel alloys ceramics and cement composites whose fundamental properties are still surprisingly little understood Although the approach has evolved over many years its potential has been recognized only relatively recently says Sidney Yip MIT professor emeritus of nuclear science and engineering and materials science and engineering who retired from teaching duties this summer after 44 years By and large the role of computers in materials science is still in the process of gaining acceptance he says Its a change of paradigm that seems to be occurring at an accelerating rate Duane Johnson a professor of materials science and engineering at the University of Illinois and a leading researcher in the field agrees that this is a major change Today as is reflected in many journal publications computational materials science is a key and often equal partner in characterization of materials often more than just to support experimental observation he says In fact computationally complex methods provide predictions that are becoming more and more reliable helping direct experiments and improve materials technologies design That change is so profound that one of the fields leading researchers MITs Gerbrand Ceder has called for a massive project somewhat analogous to the Human Genome Project to create an exhaustive database of all possible inorganic compounds (those that dont include carbon) and their properties He calls it the Materials Genome Project Computational materials science emerged a while ago and is in full bloom now says Ceder the R P Simmons Professor of Materials Science and Engineering Now his department has five or six people doing computer modeling full time he says and three people who do modeling based on first principles of physics I dont think people would have anticipated that even a few years ago he says Working in a virtual world Using the new computational methods we can use modeling almost as a microscope into the nature of materials Ceder says If you can realistically simulate the materials its a virtual world you can do controlled experiments which are difficult to do in the real world It rapidly allows you to understand things Though its been building for many years however the new approach has not yet yielded many dramatic results Yip says I think the word is potential There are not that many obvious successes so far But there are major efforts under way to bring about those successes MIT recently announced a new interdisciplinary project the Concrete Sustainability Hub (CSH) to study the fundamental properties of concrete and find ways of improving them and of reducing concretes massive carbon footprint Amazingly though the material has been in widespread use since the Roman Empire the basic structure of concrete is still not well understood Nobody knows what its fundamental structure is at the molecular level Yip says though recent work at MIT has provided significant new insights into that structure The aim of the CSH is to produce new versions of the material either with improved properties such as faster setting or greater durability or with a significant reduction in the carbon dioxide emitted by cement manufacturing The five-year project partly funded by the Portland Cement Association the industrys trade group is being led by Franz-Josef Ulm the Macomber Professor in the Department of Civil and Environmental Engineering The team working on cement science


includes several computational materials modelers including Roland Pellenq Markus Buehler Nicola Marzari Jeff Grossman and Bilge Yildiz as well as Van Vliet and Yip Understanding the detailed properties of materials still requires laboratory experiments mdash no computer models are perfect and they may never be But the guidance provided by the modeling allows the laboratory work to be done much more efficiently Ceder explains Now when you go into the lab you know what you should be doing he says Its not a random experiment anymore Inorganic oxides and concrete are not the only traditional materials coming under new scrutiny Steel alloys crucial to so much of modern life are also not well understood Yip explains that new more radiation-resistant steel alloys will be essential for the proposed new generation of nuclear power plants seen by many as an important low-carbon energy source to replace plants that consume fossil fuels Predicting steels behavior Its a great challenge Yip says If we want to extend plant lifetimes from 30 years up to 60 or 80 years we have to make sure the material can withstand the radiation damage Many people are working on that For example early computational results by Assistant Professor of Materials Science and Engineering Michael Demkowicz are pointing to several possible approaches to damage-resistant microstructures Already this approach has led to some significant progress in steel formulations says Van Vliet the Thomas Lord Associate Professor of Materials Science and Engineering For example one company was finding that steel was failing prematurely and they knew they couldnt make it better just by processing They knew it was failing in certain ways and that it could fail sooner via absorption of hydrogen from water and oil Hydrogen embrittlement is an issue for many infrastructure applications from bridges to nuclear power plants Van Vliet says and the simulations allowed the company to better understand that process Its very predictive she says allowing solutions to be developed for specific situations Other materials that are slowly yielding their secrets to the new computational techniques include the coatings applied to many common mechanical devices For example Carter says turbine blades used in jet engines may have coatings to protect them from high temperatures A bad thing would be for these blades to lose that coating he says We have used computer simulations to analyze the boundary between the coating and the material in order to understand better how the two might become separated Computational methods are also proving useful in explaining how materials change over time mdash by say undergoing gradual corrosion And in the ever-more-important field of battery research these simulations can show how the components of a lithium-ion battery for example are altered by repeated cycles of charging and discharging It gives us new insight into the behavior of these batteries Carter says We can relate the microstructure to the overall behavior of the battery The whole field is evolving and that is changing the way research is carried out and therefore the way the field is taught says Professor of Materials Science and Engineering W Craig Carter Over the next decade how you decide to teach materials science will depend on the evolution of the computer model he says MIT has played a significant role in the growth of this new approach says the University of Illinois Johnson Certainly MIT has been a leader in promoting the area of computational materials from the beginning They have maintained a strong group of quality researchers in


computational materials science and materials physics he says The MIT computational materials science faculty continue to be successful in using new and fundamental techniques And the science itself will continue to evolve dramatically Ceder believes as the computational techniques become ever more capable of automating the process of discovery and analysis Once you automate things the world changes he says But some things wont change Even as the well-controlled thought experiments offered by computational materials science will drive both the education and the experiments of the next generation of engineers the field of materials science will continue to rely on good old-fashioned trial-and-error lab work researchers say Many materials in widespread use like concrete steel and polymers are very complex organizations of many atoms which cannot possibly be simulated by computer says Carter Computational materials science appears to be generating successes in directing the nature of the experiments that should be done he says But then you still have to do the experiments to find out the real properties of the material being studied There are some properties that are almost impossible to model

MIT ENGINEERS FIND WAY TO SLOW CONCRETE CREEP TO A CRAWL Denise Brehm Civil and Environmental Engineering June 15 2009 httpwebmitedunewsoffice2009creep-0615html MIT civil engineers have for the first time identified what causes the most frequently used building material on earth -- concrete -- to gradually deform decreasing its durability and shortening the lifespan of infrastructures such as bridges and nuclear waste containment vessels In a paper published in the Proceedings of the National Academy of Sciences (PNAS) online Early Edition the week of June 15 researchers say that concrete creep (the technical term for the time-dependent deformation that occurs in concrete when it is subjected to load) is caused by the rearrangement of particles at the nano-scale Finally we can explain how creep occurs said Professor Franz-Josef Ulm [ httpceemiteduulm ] co-author of the PNAS paper We cant prevent creep from happening but if we slow the rate at which it occurs this will increase concretes durability and prolong the life of the structures Our research lays the foundation for rethinking concrete engineering from a nanoscopic perspective hellip More at httpwebmitedunewsoffice2009creep-0615html

ldquoGATHERING CONCRETE EVIDENCE MIT CLASS EXPLORES CONTROVERSIAL PYRAMID THEORY WITH SCALE MODELrdquo David Chandler MIT News Office April 2 2008 httpwebmitedunewsoffice2008pyramid-tt0402html Even though they are among the best-known structures on Earth the pyramids of Egypt may still hold surprises This spring an MIT class is testing a controversial theory that some of the giant blocks that make up the great pyramids of Giza may have been cast in place from concrete rather than quarried and moved into position


In order to help identify blocks that were cast rather than quarried students in the class Materials in Human Experience (class 3094) are assembling a small pyramid using a combination of both kinds of material They will then use techniques such as microscopic imagery and chemical analysis to look for signs that might provide ways of telling the difference on samples from the Great Pyramid itself While many people think of concrete as a recent material in fact the Romans used a version made from volcanic ash and lime extensively for most of their famous buildings including the Pantheon But although the idea that the Egyptians may have used a kind of concrete in building the pyramids was first suggested in the 1930s with a specific material that could have been used proposed in 1988 so far there has been no proof and the idea has remained mired in controversy In fact the very idea has been so controversial that you cant get research funding and its difficult to get a paper through peer review says Linn Hobbs [ httpdmsemitedufacultyfacultyhobbs ] professor of materials science and engineering and professor of nuclear science and engineering at MIT and coteacher of the pyramid-building classhellip More at httpwebmitedunewsoffice2008pyramid-tt0402html

CEMENTʼS BASIC MOLECULAR STRUCTURE FINALLY DECODED Robustness comes from messiness not a clean geometric arrangement Denise Brehm Civil and Environmental Engineering September 9 2009 httpwebmitedunewsoffice2009cement-0909html hellip The manufacture of cement is responsible for about 5 percent of all carbon dioxide emissions worldwide and new emission standards proposed by the US Environmental Protection Agency could push the cement industry to the developing world ldquoCement is so widely used as a building material that nobody is going to replace it anytime soon But it has a carbon dioxide problem so a basic understanding of this material could be very timelyrdquo said MIT Professor Sidney Yip [ httpwebmitedunsepeoplefacultyyiphtml ] co-author of a paper published online in the Proceedings of the National Academy of Sciences (PNAS) during the week of Sept 7 that announces the decoding of the three-dimensional structure of the basic unit of cement hydrate by a group of MIT researchers who have adopted the team name of Liquid Stone ldquoWe believe this work is a first step toward a consistent model of the molecular structure of cement hydrate and we hope the scientific community will work with itrdquo said Yip who is in MITrsquos Department of Nuclear Science and Engineering (NSE) ldquoIn every field there are breakthroughs that help the research frontier moving forward One example is Watson and Crickrsquos discovery of the basic structure of DNA That structural model put biology on very sound footingrdquo More at httpwebmitedunewsoffice2009cement-0909html


CEMENT AND CONCRETE RESEARCH INITIATIVES PROJECTS

CONCRETE SUSTAINABILITY HUB (CSH) 2009 Director Prof Franz-Josef Ulm httpceemiteduulm Co-Director Prof John A Ochsendorf httpceemiteduochsendorf Executive Director Hamish M Jennings httpceemitedujennings httpwebmiteducshub httpwebmiteducshubnewsnewshtml httpwebmiteducshubresearchprojectshtml More concrete is produced than any other synthetic material on Earth In the foreseeable future there is no other material that can replace concrete to meet our societies legitimate needs for housing shelter schools infrastructure etc Concrete is produced from abundant raw materials locally available almost everywhere on earth It is an inexpensive construction material with a relatively small environmental footprint but its attractive properties have lead to massive use that contributes approximately 5 of global CO2 production On the other hand emerging breakthroughs in concrete science and engineering hold the promise that concrete can be part of the solution of contributing to a sustainable development that encompasses economic growth social progress while minimizing the ecological footprint This requires a holistic approach in which progress in concrete science seamlessly feeds into innovative structural concrete engineering applications ranging from concrete pavement solutions to wall systems whose impact on sustainable development are evaluated with advanced environmental-econometric impact studies This is the focus of the Concrete Sustainability Hub (CSH) With this focus in mind an exceptional team of dedicated interdisciplinary faculty from three different schools within MIT School of Engineering School of Architecture and Planning and the Sloan School of Management are participating

Concrete Materials Science Platform One of the most critical issues for a sustainable development of concrete as the backbone material for infrastructure and housing is to address the CO2 footprint of concrete materials We propose a new way to address this issue one that is based on a shift of paradigm that will transform the way cement based materials are designed and characterized by industry for green concrete applications The basis of our paradigm-shifting R amp D is the first atomistic-scale computational model of this complex material from which we will predict new structures and improved properties that will revolutionize how cement is designed slash CO2 emissions and enable US leadership in future energy-related cement technologies To drive this idea from discovery to technology MIT scientists and engineers will leverage collaborations and industrial partnerships of the Concrete Sustainability Hub with Federal Laboratory experts and computational resources

Concrete Building Technology Platform To further drive discovery towards implementation we shall explore new materials-structural solutions for a large range of concrete engineering applications such as concrete pavements wall systems etc The focus of the concrete building technology unit is the development of aggregate models for such systems that are able to translate progress on the concrete science front (materials properties reduced environmental footprint) into added value performance criteria which include structural and life-span performance life-cycle analysis and CO2 balance investigations


























RELATED NEWS






































RELATED NEWS













brief overview of research: cement and...

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