Silica-Fume Concrete: A Solution to Steel Reinforcement - Norchem
Silica Fume in Concrete
description
Transcript of Silica Fume in Concrete
![Page 1: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/1.jpg)
Silica Fume in
Concrete
![Page 2: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/2.jpg)
Cooperative Agreement
![Page 3: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/3.jpg)
Main Outline
Understanding Silica Fume Using Silica Fume in Concrete Obtaining Silica-Fume Concrete Working With Silica-Fume Concrete Silica-Fume Concrete Projects
![Page 4: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/4.jpg)
Chapter 1. Understanding Silica Fume
Silica Fume Definitions
Silica Fume Production
Silica Fume Products
Silica Fume Reactions
Main
Outline
![Page 5: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/5.jpg)
Enhancing Mechanical PropertiesImproving Durability
Enhancing ConstructabilityProducing High-Performance
Concrete Bridges
Chapter 2. Using Silica Fume in Concrete
Main
Outline
![Page 6: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/6.jpg)
Specifying Silica Fume and SFC
Proportioning SFC
Producing SFCMain
Outline
Chapter 3. Obtaining Silica-Fume Concrete
![Page 7: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/7.jpg)
Chapter 4. Working with Silica-Fume Concrete
Conducting a Test Placement Transporting, Placing and Consolidating
Finishing Flatwork Finishing Bridge Decks
Preventing Plastic-Shrinkage Cracking Curing
Main
Outline
![Page 8: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/8.jpg)
Main
Outline
Chapter 5. Silica-Fume Concrete Projects
Bridge Decks Parking Structure
High-Rise Columns HPC Bridge
Shotcrete Rehabilitation HPC Constructability
![Page 10: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/10.jpg)
Chapter 1. Understanding Silica Fume
Silica Fume Definitions Silica Fume Production Silica Fume Products Silica Fume Reactions
![Page 11: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/11.jpg)
Silica Fume Definitions
Chapter
Outline
![Page 12: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/12.jpg)
Silica Fume ...
Very fine noncrystalline silica produced in electric arc furnaces as a byproduct of the production of elemental silicon or alloys containing silicon; also known as condensed silica fume or microsilica.
-- ACI 116R
![Page 13: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/13.jpg)
Smoke by-product from furnaces used in the production of ferrosilicon and silicon metals
Amorphous silica with high SiO2 content, extremely small particle size, and large surface area
Highly reactive pozzolan used to improve mortar and concrete
Silica Fume Summary
![Page 14: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/14.jpg)
Silica Fume (AKA)
Condensed silica fume Microsilica
“Micropoz” (trademark) Silica dust
Volatilized silica
![Page 15: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/15.jpg)
Silica Fume is NOT:
Precipitated silica Fumed silica
Gel silica Colloidal silica
Silica flour
![Page 16: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/16.jpg)
Silica Fume Health Issues
The committee is not aware of any reported health-related problems
associated with the use of silica fume in concrete.
--ACI 234R
![Page 17: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/17.jpg)
Silica fume may contain trace amounts of crystalline quartz -- requires warnings on bags
Treat as respirable dust Refer to materials safety data sheets
(MSDS) for safety measures
Silica Fume Health Issues
![Page 18: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/18.jpg)
Silica Fume Production
Chapter
Outline
![Page 19: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/19.jpg)
![Page 20: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/20.jpg)
Silica Fume Production
![Page 21: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/21.jpg)
Coal and quartz
Wood chips
![Page 22: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/22.jpg)
Quartz gravel
![Page 23: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/23.jpg)
![Page 24: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/24.jpg)
![Page 25: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/25.jpg)
![Page 26: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/26.jpg)
![Page 27: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/27.jpg)
![Page 28: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/28.jpg)
![Page 29: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/29.jpg)
Metals That Produce Silica Fume
Silicon metal - typically greater than 97% silicon
Ferrosilicon alloys -ranging from 40 to 90% silicon alloyed with iron
![Page 30: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/30.jpg)
Silica Fume Products
Chapter
Outline
![Page 31: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/31.jpg)
Silica Fume Product Forms
As-produced powder Water-based slurry Densified Blended silica-fume cement Pelletized
![Page 32: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/32.jpg)
![Page 33: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/33.jpg)
Product Characteristics --As-Produced Silica Fume
As produced directly from bag house Extremely fine and dusty Difficult to handle pneumatically -- sticky Self agglomerating with a tendency to
create small weak lumps Low density yields small loads (8 - 10 tons)
(7 - 9 Mg) in bulk tankers
![Page 34: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/34.jpg)
![Page 35: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/35.jpg)
Product Characteristics --Silica-Fume Slurry
50 - 52% solids (as-produced silica fume dispersed in water)
Storage tanks require agitation and protection from freezing
Transported in bulk tankers 4,000 gallons (12 tons of silica fume) (15 kL, 10 Mg)
![Page 36: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/36.jpg)
![Page 37: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/37.jpg)
![Page 38: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/38.jpg)
Product Characteristics --Densified Silica-Fume
Reversible agglomeration process Flows well pneumatically Bulk transportation is economical, 22
tons (20 Mg) on a bulk tanker Product density can be controlled for
handling conditions and applications
![Page 39: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/39.jpg)
![Page 40: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/40.jpg)
![Page 41: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/41.jpg)
![Page 42: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/42.jpg)
![Page 43: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/43.jpg)
Product Characteristics --Blended Silica-Fume Cement
Primarily used in Northeastern Canada, limited availability in US
Fixed silica fume content of 7.5% to 8.5% Produced from as-produced, densified, or
pelletized silica fume Portland cement-silica fume blend is primary
product. One blend of silica fume, fly ash, and portland cement now being marketed
![Page 44: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/44.jpg)
Product Characteristics --Pelletized Silica Fume
Dustless Non-reversible agglomeration Small pellets, typically 3/8 to 1 inch (10 to
25 mm) diameter Utilized in interground silica fume blended
cement
Not suitable for direct use in concrete!
![Page 45: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/45.jpg)
Premium -- White Standard -- Grey
Silica Fume Colors
![Page 46: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/46.jpg)
Silica Fume Reactions
Chapter
Outline
![Page 47: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/47.jpg)
Silica Fume -- Chemical Properties
AmorphousSilicon dioxide > 85%
Trace elements depending upon type of fume
![Page 48: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/48.jpg)
Particle size (typical) < 4 x 10 -6 in.
Bulk density
(as-produced) 8 to 27 lb/ft3
(slurry) 11 to 12 lb/gal
(densified) 30 to 45 lb/ft3
Specific gravity 2.2
Surface area (BET) 60,000 to 150,000 ft2/lb
Silica Fume -- Physical Properties
![Page 49: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/49.jpg)
Particle size (typical) < 1 µ m
Bulk density
(as-produced) 130 to 430 kg/m3
(slurry) 1320 to 1440 kg/m3
(densified) 480 to 720 kg/m3
Specific gravity 2.2
Surface area (BET) 13,000 to
30,000 m2/kgSI
Silica Fume -- Physical Properties
![Page 50: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/50.jpg)
0.0
20.0
40.0
60.0
80.0
100.0
0.1 0.3 0.5 0.7 0.9Diameter, micrometers
Perc
ent p
assin
g Typical particle
size distribution
![Page 51: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/51.jpg)
![Page 52: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/52.jpg)
Comparison of Chemical and Physical Characteristics -- Silica
Fume, Fly Ash and Cement
Comparison of Chemical and Physical Characteristics -- Silica
Fume, Fly Ash and Cement
Silica FumeSilica Fume Fly AshFly Ash CementCement
SiO2 Content 85- 9785- 97 35 - 48 35 - 48 20 -25 20 -25
Surface Area m2/kg 17,000 - 30,00017,000 - 30,000 400 - 700 400 - 700 300 - 500 300 - 500
Pozzolanic Activity(with cement, %) 120 - 210120 - 210 85 - 110 85 - 110 n/a n/a
Pozzolanic Activity(with lime, psi) (MPa) 1,200 - 1,660 1,200 - 1,660 800 - 1,000 800 - 1,000 n/a n/a
(8.3 - 11.4)(8.3 - 11.4) (5.5 - 6.9) (5.5 - 6.9)
![Page 53: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/53.jpg)
How Does Silica Fume Work in Concrete?
Physical effectChemical effect
![Page 54: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/54.jpg)
Silica Fume: Physical Effect
The presence of any type of very small particles will improve
concrete properties. This effect is termed either “particle packing” or
“micro filling”.
![Page 55: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/55.jpg)
The carbon black and plain cement mixes showed comparable strengths at both 7 and 28 days, even though the carbon black mixes contained 10 percent less cement (by mass) ... physical mechanisms do play a significant role, particularly at early ages.
-- Detwiler and Mehta
ACI Materials Journal
Physical Effect
![Page 56: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/56.jpg)
![Page 57: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/57.jpg)
Silica Fume: Chemical Effect
Silica fume is simply a very effective pozzolanic material
![Page 58: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/58.jpg)
A siliceous or siliceous and aluminous material, which in itself possess little or no cementitious value but will, in finely divided form and in the presence of
moisture , chemically react with calcium hydroxide at ordinary temperatures to
form compounds possessing cementitious properties.
-- ACI 116R
What is a Pozzolan?
![Page 59: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/59.jpg)
portland cement + water=
calcium silicate hydrate+
calcium hydroxide
![Page 60: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/60.jpg)
pozzolan + calcium hydroxide+
water=
calcium silicate hydrate
![Page 61: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/61.jpg)
![Page 62: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/62.jpg)
The Transition Zone
The transition zone is a thin layer between the bulk hydrated cement
paste and the aggregate particles in concrete. This zone is the weakest
component in concrete, and it is also the most permeable area. Silica fume plays a significant role in the transition
zone through both its physical and chemical effects.
![Page 63: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/63.jpg)
![Page 64: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/64.jpg)
![Page 65: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/65.jpg)
![Page 66: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/66.jpg)
![Page 67: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/67.jpg)
![Page 68: Silica Fume in Concrete](https://reader034.fdocuments.in/reader034/viewer/2022050719/56814eaf550346895dbc58f4/html5/thumbnails/68.jpg)
End of Chapter 1
Main
Outline