Portland Cement Concrete Figure 2-9
Topics—Hydraulic Cements—Ch. 2 (PCA) • • • • • • • •
Portland Cement Concrete Chapter 2—Hydraulic Cements CEE 363 Construction Materials
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Introduction Types of cements Physical properties of cements Production of cements Cement supply Location of Washington State cement plants Transportation and packaging of cement Storage of cement
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Figure 2-9
Figure 2-2 The naming of portland cement
Joseph Aspdin patented portland cement in 1824. He noted that it resembled the rock on the Isle of Portland.
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Types of Cements
Types of Cements
• Type I: General purpose cement. • Type II: Protects PCC against moderate sulfate attack. Generates less heat than Type I. Some cement manufacturers can meet both the Type I and II requirements with one cement. • Type III: Provides high strength PCC with a shorter cure period. Similar to Type I but the clinker is ground finer—thus allowing more rapid hydration.
• Type IV: Produces less heat during hydration but slower strength gain. Sometimes used with mass concrete. • Type V: Used for PCC exposed to severe sulfate action from soils or groundwater. • Blended Cements: Refer to Chapter 2. • Special Cements: A wide variety of cements are available for specific applications—refer to Table 2-4, Chapter 2. 6
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Figure 2-31
Figure 2-27
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Physical properties of cements
Physical properties of cements
Physical properties include: • • • •
Particle size and fineness Soundness Consistency Setting time
• Particle size and fineness – Average particle size of cement is 15 μm. – Fineness is the overall particle size distribution—this affects the rate of hydration.
• Loss on ignition • Specific gravity • Bulk density
• Soundness – Ability of hardened paste to retain its volume.
– Initial set – Final set
• Setting time – Initial set: Time from adding water until paste ceases to be fluid. – Final set: Time required for paste to acquire a certain hardness.
• False set and flash set • Compressive strength • Heat of hydration 9
10
Hydraulic Cements—Production
Figure 2-38
World cement production for 2003—top 10 producing countries
Country
Production (millions metric tons)
1. 2. 3. 4.
China 750 India 110 US including Puerto Rico 93 Japan 72
5. 6. 7. 8. 9.
Korea Brazil Italy Russia Spain
56 40 40 40 40
10. Thailand
35
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2
Hydraulic Cements—Production •
US production in 2003: – – –
• •
Hydraulic Cements—Production •
87 million metric tons of portland cement 4.5 million tons of masonry cement Produced at 118 plants in 37 states and Puerto Rico by 39 companies.
Annual imports of hydraulic cement: 21 million tons Total cement use in US: 112 million tons/year (imports about 20% of consumption)
13
Import sources: – – – – –
•
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Cement Shortages in the US--2004
19% Canada 18% Thailand 12% China 7% Venezuela 44% Others (32 other countries)
US cement applications: – – – –
75% to ready-mixed concrete producers 13% to concrete product manufacturers 6% to contractors (mostly road paving) 6% others
Cement Shortages in the US--2004
• US cement supply is currently short of demand—why? – Strong construction markets – Long lead times needed to bring new cement plants online (permitting process) and lots of capital. – Freight • Limited availability of transport ships for importing more cement • Shipping rates increased significantly during 2004 15
16
Local Cement Production--South Seattle Industrial Area
Local Cement Production • In Seattle, portland cement is produced by – Ash Grove Cement – Lafarge Cement (formerly Holnam Cement and before that Idea Cement)
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Location of Ash Grove and Lafarge Plants in Seattle
Ash Grove and Lafarge Plants in Seattle—Use of Scrap Tires as Fuel • Both cement plants in Seattle use scrap tires as a portion of the fuel for their kilns. • National-wide about 290 million scrap tires are generated each year with about 233 million being consumed (or about 80%). • Cement plants are estimated to consume about 53 million tires per year (or 18% of total scrap tires generated). • Benefits to cement manufacturers
West Seattle Bridge
Ash Grove Plant Site Lafarge Plant Site
– Reduces energy costs – Less nitrogen oxide emissions compared to other fuels – Tire-derived fuel (TDF) is becoming a “standard practice.” Refer to ASTM D6700.
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Transportation and Packaging of cement
Storage of cement
• Most cement is shipped via rail, truck, barge, or ship • Bags are 42 kg (92.6 lb) with a volume of 28 liters.
• If kept dry, can be stored indefinitely. The trick is to keep it dry!
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References
References
• Powers, T. and Brownyard, T. (1948), “Studies of the Physical Properties of Hardened Portland Cement Paste,” Bulletin 22, Portland Cement Association, reprint from the Journal of the American Concrete Institute, Detroit, Michigan, March 1948.
• RMA (2003), “US Scrap Tire Markets,” 2003 Edition, Rubber Manufacturers Association, Washington, DC, July 2004. • ICC (2000), “International Building Code,” International Code Council, Falls Church, Virginia, March 2000.
• Hosmatka, S., Kerkoff, B., and Panarese, W. (2003), “Design and Control of Concrete Mixtures,” 14th Edition, Portland Cement Association, Skokie, Illinois.
• ACI (2003), “Mass Concrete,” ACI 207.1R-96, ACI Manual of Concrete Practice—Part 1—2003, American Concrete Institute, Farmington Hills, MI.
• USGS (2004), “Mineral Commodity Summaries,” US Geological Survey, January 2004.
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Portland Cement Concrete Chapter 2—Hydraulic Cements CEE 363 Construction Materials
1
Introduction Types of cements Physical properties of cements Production of cements Cement supply Location of Washington State cement plants Transportation and packaging of cement Storage of cement
2
Figure 2-9
Figure 2-2 The naming of portland cement
Joseph Aspdin patented portland cement in 1824. He noted that it resembled the rock on the Isle of Portland.
3
5
4
Types of Cements
Types of Cements
• Type I: General purpose cement. • Type II: Protects PCC against moderate sulfate attack. Generates less heat than Type I. Some cement manufacturers can meet both the Type I and II requirements with one cement. • Type III: Provides high strength PCC with a shorter cure period. Similar to Type I but the clinker is ground finer—thus allowing more rapid hydration.
• Type IV: Produces less heat during hydration but slower strength gain. Sometimes used with mass concrete. • Type V: Used for PCC exposed to severe sulfate action from soils or groundwater. • Blended Cements: Refer to Chapter 2. • Special Cements: A wide variety of cements are available for specific applications—refer to Table 2-4, Chapter 2. 6
1
Figure 2-31
Figure 2-27
7
8
Physical properties of cements
Physical properties of cements
Physical properties include: • • • •
Particle size and fineness Soundness Consistency Setting time
• Particle size and fineness – Average particle size of cement is 15 μm. – Fineness is the overall particle size distribution—this affects the rate of hydration.
• Loss on ignition • Specific gravity • Bulk density
• Soundness – Ability of hardened paste to retain its volume.
– Initial set – Final set
• Setting time – Initial set: Time from adding water until paste ceases to be fluid. – Final set: Time required for paste to acquire a certain hardness.
• False set and flash set • Compressive strength • Heat of hydration 9
10
Hydraulic Cements—Production
Figure 2-38
World cement production for 2003—top 10 producing countries
Country
Production (millions metric tons)
1. 2. 3. 4.
China 750 India 110 US including Puerto Rico 93 Japan 72
5. 6. 7. 8. 9.
Korea Brazil Italy Russia Spain
56 40 40 40 40
10. Thailand
35
11
2
Hydraulic Cements—Production •
US production in 2003: – – –
• •
Hydraulic Cements—Production •
87 million metric tons of portland cement 4.5 million tons of masonry cement Produced at 118 plants in 37 states and Puerto Rico by 39 companies.
Annual imports of hydraulic cement: 21 million tons Total cement use in US: 112 million tons/year (imports about 20% of consumption)
13
Import sources: – – – – –
•
14
Cement Shortages in the US--2004
19% Canada 18% Thailand 12% China 7% Venezuela 44% Others (32 other countries)
US cement applications: – – – –
75% to ready-mixed concrete producers 13% to concrete product manufacturers 6% to contractors (mostly road paving) 6% others
Cement Shortages in the US--2004
• US cement supply is currently short of demand—why? – Strong construction markets – Long lead times needed to bring new cement plants online (permitting process) and lots of capital. – Freight • Limited availability of transport ships for importing more cement • Shipping rates increased significantly during 2004 15
16
Local Cement Production--South Seattle Industrial Area
Local Cement Production • In Seattle, portland cement is produced by – Ash Grove Cement – Lafarge Cement (formerly Holnam Cement and before that Idea Cement)
17
18
3
Location of Ash Grove and Lafarge Plants in Seattle
Ash Grove and Lafarge Plants in Seattle—Use of Scrap Tires as Fuel • Both cement plants in Seattle use scrap tires as a portion of the fuel for their kilns. • National-wide about 290 million scrap tires are generated each year with about 233 million being consumed (or about 80%). • Cement plants are estimated to consume about 53 million tires per year (or 18% of total scrap tires generated). • Benefits to cement manufacturers
West Seattle Bridge
Ash Grove Plant Site Lafarge Plant Site
– Reduces energy costs – Less nitrogen oxide emissions compared to other fuels – Tire-derived fuel (TDF) is becoming a “standard practice.” Refer to ASTM D6700.
19
20
Transportation and Packaging of cement
Storage of cement
• Most cement is shipped via rail, truck, barge, or ship • Bags are 42 kg (92.6 lb) with a volume of 28 liters.
• If kept dry, can be stored indefinitely. The trick is to keep it dry!
21
22
References
References
• Powers, T. and Brownyard, T. (1948), “Studies of the Physical Properties of Hardened Portland Cement Paste,” Bulletin 22, Portland Cement Association, reprint from the Journal of the American Concrete Institute, Detroit, Michigan, March 1948.
• RMA (2003), “US Scrap Tire Markets,” 2003 Edition, Rubber Manufacturers Association, Washington, DC, July 2004. • ICC (2000), “International Building Code,” International Code Council, Falls Church, Virginia, March 2000.
• Hosmatka, S., Kerkoff, B., and Panarese, W. (2003), “Design and Control of Concrete Mixtures,” 14th Edition, Portland Cement Association, Skokie, Illinois.
• ACI (2003), “Mass Concrete,” ACI 207.1R-96, ACI Manual of Concrete Practice—Part 1—2003, American Concrete Institute, Farmington Hills, MI.
• USGS (2004), “Mineral Commodity Summaries,” US Geological Survey, January 2004.
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