NANOTECHNOLOGY APPLIED IN THE DESIGN OF THE NEXT ...
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The pavement surface should be designed to provide high friction, smooth surface, low noise and adequate surface drainage. PCC pavements has two primary functional “failures”: inadequate skid resistance and excessive tire-pavement noise generation. Friction is affected by both the microtexture, and by the macrotexture. Noise emission is affected mainly by macrotexture. Previous research on friction and sound production of concrete pavement mostly emphasized creating different surface textures through macrotexture modifications. In this research the focus is to investigate how friction and sound absorption can be improved by modifying the concrete microtexture through nanotechnology and varying surface characteristics through macrotexture modifications. Develop a new surface concrete pavement with increased friction and noise absorption (less overall noise production). Develop and propose a new concrete texture with increased durability. To date, several mixes have been evaluated in the laboratory. The mix design was assembled based on the CSA A23.1- 09/A23.2-09 standard using the following parameters: • Slump: 75 mm to 100 mm; air content: 5% to 8% (tolerance: ±1.5%); specified compressive strength at 28 days: 35 MPa; class of exposure: C – 2, nominal maximum size of aggregate: 20 mm, Concretes mixes include the following materials: • Normal Portland cement (Type GU); aggregates (coarse and fine); High-range water reducing (HRWRA) and air-entraining admixture (AEA) and nanosilica (defined in proportion to the cement weight). The main tests performed to date are the following: Scanning Electron Microscope (SEM) images of hardened concrete Adding a small amount of nanosilica to a concrete mix improves: The compressive strength, the friction response characterized by the British Pendulum Number, and the abrasion response. Nanosilica also acts as a supplementary cementing material in the mix, improving the concrete’s microstructure. Improvements in the paste density and in the aggregate-paste bond, and a reduction of ettringuite formation in voids are detected by SEM images. NANOTECHNOLOGY APPLIED IN THE DESIGN OF THE NEXT GENERATION OF CONCRETE PAVEMENTS SURFACE Marcelo Gonzalez 1 and Susan L. Tighe 2 1: PhD Candidate. 2: PhD, P.Eng. Professor and Canada Research Chair, Norman W. McLeod Professor, Director of CPATT Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, Ontario, Canada INTRODUCTION OBJECTIVES RESULTS AND DISCUSSION RESULTS AND DISCUSSION ACKNOWLEDGEMENTS The authors acknowledge the support and contribution of the Cement Association of Canada, particularly Rico Fung who is the Director of Markets and Technical Affairs in Ontario. In addition, the authors are grateful to BASF Canada for the supply of chemical admixtures used in the present study. The authors are also thankful to the following additional institutions: Natural Sciences and Engineering Research Council of Canada (NSERC), Chilean Government - Program International Scholarship (CONICYT), Ministry of Transportation Ontario (MTO), and Waterloo Institute of Nanotechnology (WIN). Macrotexture Microtexture RESEARCH METHODOLOGY CONCLUSIONS TO DATE • TEM and chemical analysis of nanosilica • Slump, air content and density • Compressive strength • Friction response characterized by the British Pendulum Number • Abrasion response using the rotating-cutter drill press • SEM of hardened concrete TEM and chemical analysis of nanosilica Slump, air content and density Compressive strength Friction using the British Pendulum Number (BPN) Abrasion response using the rotating-cutter drill press O Si Na 69.6 28.4 2.01 53.9 45.2 0.86 71.1 28.4 0.59 Atomic percentage (%) of each element Chemical analysis using EDAX Mix Nanosilica (% ) Slump (mm) Air Content (% ) Density (Kg/m 3 ) AEA (l/m 3 ) HRWR (l/m 3 ) Mix 1 (CC 1 ) 0 95 4 2436 0.28 3.78 Mix 2 (NSC 2 1) 0.5 95 5.5 2379 0.60 4.78 Mix 3 (NSC 2) 1 95 5.9 2379 0.72 5.17 Mix 4 (NSC 3) 1.5 90 5.4 2387 0.96 6.57 1 CC: Control concrete, 2 NSC: Nano silica concrete W/C = 0.31 Mix Nanosilica (% ) Slump (mm) Air Content (% ) Density (Kg/m 3 ) AEA (l/m 3 ) HRWR (l/m 3 ) Mix 1 (CC 1 ) 0 82 7 2365 0.19 3.10 Mix 2 (NSC 2 1) 0.5 90 5.9 2379 0.19 3.29 Mix 3 (NSC 2) 1 85 5.2 2379 0.21 3.68 Mix 4 (NSC 3) 1.5 75 5 2401 0.24 4.26 Mix 5 (NSC 4) 2 90 6.5 2365 0.29 4.26 1 CC: Control concrete, 2 NSC: Nano silica concrete W/C = 0.39 0 10 20 30 40 50 60 70 80 0.0 0.5 1.0 1.5 Compressive Strength (MPa) % Nanosilica 7 Days 28 Days 0 10 20 30 40 50 60 70 80 0.0 0.5 1.0 1.5 2.0 Compressive Strength (MPa) % Nanosilica 7 Days 28 Days (W/C = 0.31) (W/C = 0.39) 0 10 20 30 40 50 60 70 0 0.5 1 1.5 BPN % Nanosilica 7 Days 28 Days 0 10 20 30 40 50 60 70 0.0 0.5 1.0 1.5 2.0 BPN % Nanosilica 7 Days 28 Days (W/C = 0.31) (W/C = 0.39) Broom Smooth 0 1 2 3 4 5 6 7 8 9 10 0.0% 0.5% 1.0% 1.5% 2.0% Loss of weight (gr) % Nanosilica 7 days - broom 28 days - broom 7 days - smooth 28 days - smooth Linear (7 days - broom) Linear (28 days - broom) Linear (7 days - smooth) Linear (28 days - smooth) (W/C = 0.39) a) 0.0% NS – 10 µm b) 2.0% NS – 10 µm c) 0.0% NS – 1 µm e) 0.0% NS – 100 nm d) 2.0% NS – 1 µm f) 2.0% NS – 100 nm
Transcript of NANOTECHNOLOGY APPLIED IN THE DESIGN OF THE NEXT ...
The pavement surface should be designed to provide high friction, smooth surface, low noise and adequate surface drainage.
PCC pavements has two primary functional “failures”: inadequate skid resistance and excessive tire-pavement noise generation.
Friction is affected by both the microtexture, and by the macrotexture. Noise emission is affected mainly by macrotexture.
Previous research on friction and sound production of concrete pavement mostly emphasized creating different surface textures through macrotexture modifications.
In this research the focus is to investigate how friction and sound absorption can be improved by modifying the concrete microtexture through nanotechnology and varying surface characteristics through macrotexture modifications.
Develop a new surface concrete pavement with increased friction and noise absorption (less overall noise production).
Develop and propose a new concrete texture with increased durability.
To date, several mixes have been evaluated in the laboratory. The mix design was assembled based on the CSA A23.1-09/A23.2-09 standard using the following parameters:
• Slump: 75 mm to 100 mm; air content: 5% to 8% (tolerance: ±1.5%); specified compressive strength at 28 days: 35 MPa; class of exposure: C – 2, nominal maximum size of aggregate: 20 mm,
Concretes mixes include the following materials:
• Normal Portland cement (Type GU); aggregates (coarse and fine); High-range water reducing (HRWRA) and air-entraining admixture (AEA) and nanosilica (defined in proportion to the cement weight).
The main tests performed to date are the following:
Scanning Electron Microscope (SEM) images of hardened concrete
Adding a small amount of nanosilica to a concrete mix improves:
The compressive strength, the friction response characterized by the British Pendulum Number, and the abrasion response.
Nanosilica also acts as a supplementary cementing material in the mix, improving the concrete’s microstructure.
Improvements in the paste density and in the aggregate-paste bond, and a reduction of ettringuite formation in voids are detected by SEM images.
NANOTECHNOLOGY APPLIED IN THE DESIGN OF THE NEXT GENERATION OF CONCRETE PAVEMENTS SURFACE Marcelo Gonzalez1 and Susan L. Tighe2
1: PhD Candidate. 2: PhD, P.Eng. Professor and Canada Research Chair, Norman W. McLeod Professor, Director of CPATT Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, Ontario, Canada
INTRODUCTION OBJECTIVES RESULTS AND DISCUSSION RESULTS AND DISCUSSION
ACKNOWLEDGEMENTS The authors acknowledge the support and contribution of the Cement Association of Canada, particularly Rico Fung who is the Director of Markets and Technical Affairs in Ontario. In addition, the authors are grateful to BASF Canada for the supply
of chemical admixtures used in the present study. The authors are also thankful to the following additional institutions: Natural Sciences and Engineering Research Council of Canada (NSERC), Chilean Government - Program International Scholarship (CONICYT), Ministry of Transportation Ontario (MTO), and Waterloo Institute of Nanotechnology (WIN).
Macrotexture
Microtexture
RESEARCH METHODOLOGY
CONCLUSIONS TO DATE
• TEM and chemical analysis of nanosilica
• Slump, air content and density
• Compressive strength
• Friction response characterized by the British Pendulum Number
• Abrasion response using the rotating-cutter drill press
• SEM of hardened concrete
TEM and chemical analysis of nanosilica
Slump, air content and density
Compressive strength
Friction using the British Pendulum Number (BPN)
Abrasion response using the rotating-cutter drill press
O Si Na69.6 28.4 2.0153.9 45.2 0.8671.1 28.4 0.59
Atomic percentage (%) of each elementChemical analysis using EDAX
MixNanosilica
(% )Slump (mm)
Air Content (% )
Density (Kg/m3)
AEA (l/m3)
HRWR (l/m3)
Mix 1 (CC1) 0 95 4 2436 0.28 3.78
Mix 2 (NSC2 1) 0.5 95 5.5 2379 0.60 4.78Mix 3 (NSC 2) 1 95 5.9 2379 0.72 5.17Mix 4 (NSC 3) 1.5 90 5.4 2387 0.96 6.571CC: Control concrete, 2NSC: Nano silica concrete
W/C = 0.31
MixNanosilica
(% )Slump (mm)
Air Content (% )
Density (Kg/m3)
AEA (l/m3)
HRWR (l/m3)
Mix 1 (CC1) 0 82 7 2365 0.19 3.10
Mix 2 (NSC2 1) 0.5 90 5.9 2379 0.19 3.29Mix 3 (NSC 2) 1 85 5.2 2379 0.21 3.68Mix 4 (NSC 3) 1.5 75 5 2401 0.24 4.26Mix 5 (NSC 4) 2 90 6.5 2365 0.29 4.261CC: Control concrete, 2NSC: Nano silica concrete
W/C = 0.39
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