belkowitz presentation 4-13-10.pdf

7/30/2019 Belkowitz Presentation 4-13-10.pdf

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2010 Concrete Sustainability Conference 1 National Ready Mixed Concrete Association

AN INVESTIGATION OF NANO SILICA (SiO2) IN THE

Dr Daniel ArmentroutUniversity of Denver

Jon BelkowitzStevens Institute of Technology

,,


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Overview

Introduction

A Brief History of Concrete What Makes This Pro ect Uni ue? Comparing new vs old materials

What has been investigated

Materials and Experiments What worked

What didnt work

The Cement Hydration Process 5 Stages of the Heat of Hydration

Results and Analysis What Happened

Summary

Questions

References


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A Brief History of Concrete

Concrete Technology throughtime (Finding Solutions in theFace of Adversity)

Appian, Rome: Circa 125 BC

First Concrete Roadway,Ohio: 1893

Confederation Bridge,Canada: 1993

Problems in Need of Solutions Concrete/Cement Expensive

ASR , Min. Fly Ash Req. GAO 85 10R

Api an - Rome

Courtesy of Univ of Knowledge, 1938.

1stConcr ete Roadway Ohio 1893

Courtesy of Univ of Knowledge, 1938.

Engineering Responsibility

Preserving the Environment

Economic Vitality Durable/Sustainable

Roadways

Confederate Brid ge Canada 1993

Courtesy of w ww.ConfederateBridg e.com , 1995.


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What Makes this Project Unique?

Comparing old vs new materials Silica, a pozzolanic material

Introduced in the 1970s

,

Introduced in the new millennium

What has been investigated

A nano silica changing a microscopic crystal

structure which has macroscopic affects.


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Materials and Ex eriments

Constituents

Type I/II Portland Cement Polycarboxylate Comb

Polymer (HRWR)

Silica

x es gn No Aggregate w/c of 0.32

re m nary r a s

Contamination

Modifying the Standards


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Materials Silica Fume SF

This byproduct is the result of

the reduction of high-purity

arc furnace in the manufactureof silicon or ferrosilicon alloy.(PCA 60).

Surface area of SF ~ 20,000m2/kg

Cigarette smoke ~ 10,0002

Size ~ Average 1.0 m

ST DEV of 0.5 m Variability


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Materials Nano Silica

Less variability

Mix 8, Size ~ Average 35 nm

Range of sizes: 2 to 100 nm

Mix 50 Size ~ Avera e 5.5 nm

Range of sizes: 4 to 6 nm Mix 508: Combination of 8 and 50

Manufacturers Specification

Diameter > 40 nm, Filler

Diameter < 10 nm, Chemical

Micrograph of Nano Particles

From Brian H. Green at the Army Corp of Engineers


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Experimentsa r e scuss on on an ar s

Calorimetry Grace Adiacal, Semi-Adiabatic

Calorimetric Chamber

S ecimens: 76.2 mm diam. b152.4 mm (length)

Standard: ASTM C 31-09

X-Ray Diffraction Siemmins E500, X-Ray Diffractor

10 mm

Standard: N/A

Scanning Electron Microscopy Jeoul 5800 LV, Scanning

Specimens: 25 mm by 50 mm by10 mm

Standard: N/A Compressive Tests ,

Hydraulic Press

Specimen: 50 mm by 50 mm by50 mm

Standard: ASTM C 109-08


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Cement H dration Process Stage 1

Stage 2, 3, & 4

633 AHCHAC + 6

)(OH)(Ca3HSC)O(H6)S(C2 232323 ++

Stage 4, 5

Pozzolanic Reaction

232322 (OH)CaHSC)O(H4)S(C2 ++

23232 (OH)CaHSC(OH)CaS ++


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Results Calorimetry

SF MIX, POZZ REACTION AT 120 Hr


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Results XRD


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Results - SEM

Mix ST CM Mix SF


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Results SEM, Contd

Mix 8 Mix 50

Mix 508


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Results SEM, Contd

Mix 508 Mix 8


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Results Compressive

90.00

100.00

M

Pa)

60.00

70.00

80.00

veStrength

8

508

50

30.00

40.00

50.00

Compre

ssi

SFST CMT

20.00

0 5 10 15 20 25 30

Time (Days)

ST DEV for all mixes conformed to the ASTM C 109-08

Did not exceed 3.5 MPa (500PSI) between samples


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Summar

Thesis Goals

Cement Hydration Process

As the Size of the Nano Particle

Increases Increase in Temperature

Possibility of a Change in CSH

Increase in Compressive Strength,


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QUESTIONS


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References ASTM C 31-09. Standard Practice for Making and Curing Concrete Test Specimens inthe Field. ASTM International. 2009. - .

Cement Mortars. ASTM International. 2008.

Balaguru, P., and Chong, K. Nanotechnology and Concrete: Research Opportunities.

ACI SP-2008.

Bentz, D.P. Influence of silica fume on diffusivity in cement-based materials. II.

Multi-scale modeling of concrete diffusivity. National Institute of Standards and

Technology. July 2000. Berger, R. and McGregor, J. Influence of Admixtures on the Morphology of Calcium

Hydroxide Formed During Tricalcium Silicate Hydration. Cement and Concrete Research. 1972.

Bogue, Robert. Chemistry of Portland Cement. Reinhold. 1955.

Christensen P. Structural and Ingredient Analysis of Concrete Methods, Results,

and Experience. Nordisk Betong. 1984.

Gartner, E., Young, J. Damidot, D. and I Jawed. Hydration of Portland Cement.

Lafarge. 2000.

Green, B. Development of a High-Density Cementitious Rock-Matching Grout using

Nano-Particles. SP-2548. Nanotechnology of Concrete: Recent Developments and Future Perspectives. ACI. K. Sobolevand S.P. Shah. 2008. pp. 121 132.

Holland, T. Silica Fume Users Manual. Silica Fume Association. April 2005. p. 4.

Larsen, G. Microscopic Point Measuring: A Quantitative Petrographic Method ofDetermining the Ca(OH)2 Content of the Cement Paste in Concrete. Magazine of Concrete Research. 1961.

Mindess, Sydney, J. Young, and, D, Darwin. Concrete. 2nd Edition. Prentice Hall.

2003.

Neville, A. M. Properties of Concrete. 14th Edition. Prentice Hall. 2002.

Reed, Matt. Nano Silica Particle Size and Distribution. Eka Chemicals. EmailInterview. 22 June 2009.

Sobolev, K., I. Flores, R. Hermosillo, and L.M. Torres-Martinez. Nanomaterials and Nanotechnology for High-Performance Cement Composites. SP-2548. Nanotechnology of

Concrete: Recent Developments and Future Perspectives. ACI. K. Sobolev and S.P. Shah. 2008. pp. 93 120

Spinks, J.W.T., H. W. Baldwin, and T. Thorvaldson. Tracer Studies of diffusion in set

Portland Cement. Can. J. Technol. Vol. 30. 1952.

St John, Donald, Poole, A., and Ian Sims. Concrete Petrography. Elsevier. 1998.


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Acknowled ements

Whitney Bitter

Harry and Pearl Belkowitz

Dr Daniel Armentrout Dr Maciej Kumosa

Dr Paul Predecki

Brian Burks

James Middleton

Daniel St-Pierre

Matt McCombs Lafarge Asphalt Crew

Peggy Martinez

Kevin Sobczak

Renee Teixeira

The Folks at Chryso, Inc

The Folks at Cemex

The Folks at W.R. Grace

The Best Family

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