# Presentation: 524909

## Virtual Cement and Concrete Testing Laboratory (VCCTL) Consortium:Questions and Answers

- Dale P. Bentz
- Building and Fire Research Laboratory
- June 13, 2000

## Who will the participants be?

- NIST
- Building and Fire Research Laboratory
- Materials Science and Engineering Laboratory
- Information Technology Laboratory
- Industry
- CEMEX		- Dyckerhoff Zement
- Holnam		- Master Builders
- Lafarge		- W.R. Grace & Co.
- Others (ACI, other companies)

## What is the consortium developing?

- A virtual cement and concrete testing laboratory
- Internet-based and menu driven
- predicts properties based on detailed microstructure simulations of well-characterized starting materials
- ultimately tailored to each company’s research interests

## Properties Predicted by the VCCTL

*yield stress and viscosity of the fresh material*
- setting time
- volumes of hydration reactants and products as a function of hydration time
- chemical shrinkage
- adiabatic heat signature
- percolation properties
- ITZ microstructure
- diffusivities, thermal, and electrical conductivity
*elastic properties*
- compressive strength development
- susceptibility to common degradation mechanisms

## When and Where?

- When
- starting in FY 2001 (Jan. 2001 for company participation) and going for at least 3 years (and possibly much longer)
- Where
- NIST and the participating companies’ research centers (national and international)

## How will the consortium operate?

- Multiple mechanisms for technology transfer
- joint research
- guest researchers at NIST
- NIST researchers at industrial sites for installation/training/joint research
- VCCTL web site at NIST and company sites

## Why should a virtual laboratory for concrete testing be developed?

- Physical testing of concrete is expensive
- raw materials
- storage space (materials and curing)
- manpower for preparation and testing
- disposal costs
**time** : need to cure for at least 28 days in general before testing

## Why should a virtual laboratory for concrete testing be developed?

- Research and development currently hindered by:
- inadequate characterization of starting materials
- large number of variables
- long delay between specimen preparation and testing
- environmental and operator variability
- cost of research

## Why should a virtual laboratory for concrete testing be developed?

- Environmental issues
- reduced CO2 emissions
- “wasting” cement in low w/c ratio concretes
- introduction of new materials
- construction industry slow to accept new systems

## Current testing of concrete

- Obtain raw materials in sufficient quantities for concrete mixtures (hundreds of kg)
- characterize raw materials
- design concrete mixtures
- prepare concrete mixtures
- cure concrete mixtures (>= 28 days)
- test concrete mixtures
- dispose of tested materials
- revise mixtures proportions and repeat

## Virtual Testing of Concrete

- Obtain raw materials in sufficient quantity for characterization and making cement paste samples (hundreds of grams)
**characterize raw materials**
- design mixtures
- simulate microstructure development       and/or prepare cement paste specimens
- evaluate properties
- revise mixtures and repeat

## Current vs. Virtual Testing

- Current testing
- physical based
- manpower intensive
- materials intensive
- weeks/months
- high disposal costs

- Virtual testing
- computer based
- computation intensive
- small material needs
- days
- low disposal costs

**Other industries (pharmaceuticals, etc.) have **
**successfully gone this route.  Is now the time for the**
**cement & concrete industry to be proactive and **
**follow suit??**

## Typical Costs for Concrete Testing ($300/batch)

## Startup Costs for Virtual Lab

- PC system with VCCTL installed
- Pentium III 600 MHz, 512 Mbyte RAM
- $2500
- Participation in NIST/industry VCCTL
- $40 K/yr
**Industry researcher to work with the VCCTL consortium**

## Why should NIST coordinate this activity?

- “Best in the World” (#1) in the computational materials science of concrete
- strong synergism between experimental and modeling research programs
- past experience in developing successful Web-based applications
- one of our mandates is to assist industry
- (dozens of NIST/industry consortia exist)
- active in standards and international organizations (ASTM, ACI, RILEM, ISO)

## Why should NIST coordinate this activity?

- Objectivity (neutral party as coordinator)
- State-of-the-art equipment for experiments and computations (see handout)
- Human resources (Experts in):
- cement hydration and microstructure
- rheology
- transport and mechanical properties
- computer modeling
- particle and microstructure characterization
- visualization
- WWW development

## Benefits for Consortium Participation

- VCCTL onsite installation and training (onsite or at NIST)
- source code for the VCCTL
- access to extensive NIST facilities and personnel for joint research
- consultation on adapting VCCTL to company’s interest & needs
**participation in a focused project with a clear-cut objective that is directed by the interests and needs of the industry**

## Leveraging of Funds (Best Case)

## Leveraging of Funds (Worst Case)

## Possible Initial Consortium Topics

- Sulfate additions
- Influence of alkalis
- Strength and rheological property predictions for blended cement concretes
- Slag/kaolin additions to CEMHYD3D
- Influence of chemical admixtures
- Controlled PSD to optimize rheological and early-age properties of cement-based materials (cements blended with inert fillers)

## Where do we go from here?

- Obtain commitments in writing from industry participants
- Prioritize and detail research topics
- Develop and obtain approval for a **memorandum of understanding (MOU)** outlining consortium objectives, resources, and financial and intellectual exchange

## More Questions

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