MÔN học vật LIỆU xây DỰNG mới NOVEL BUIDING MATERIALS

Silica Fume• Production of Silica Fume; • Physical and Chemical Characteristics of Silica Fume; • Physical and Chemical Mechanisms in the Cement– Silica Fume System; •• • Properties of F

Môn học: VẬT LIỆU XÂY DỰNG MỚI

NOVEL BUILDING MATERIALS

The University of Transport and Comunication

Civil Engineering Institute

Building Materials Section

Presented by: Dr Thanh Sang NGUYEN

Mobile: 0983316711 Mobile: 0983316711; ; Email

Email: sanguct@gmail.com : sanguct@gmail.com

NỘI DUNG - CONTENT

 (Introduction)

 (HPC – High Performance Concrete)

 (High Performace Asphalt Pavement)

 (Advanced Steel for use in civil engineering)

 (Fibre-Reinforced Composit-FRP)

Tham khảo - References (1)

 S.P Shah and S.H Ahmad, High Performance Concretes and

 S.P Shah and S.H Ahmad, High Performance Concretes and Applications, USA, 1994;

 C.W Wu, John W.Bull, Durability of Materials and Structure in Building and Civil Engineering, 2006

 V.M Malhtra, High performance, high-volume fly ash concrete

- USA, 2008

 Many Papers, Thesis from 2000 to now.

Tham khảo - References (2)

Vietnamese:

GTVT 2010;

lượng cao, Nhà xuất GTVT, 2010;

Giới thiệu chung - Introduction

Người cổ đã biết dùng vật liệu đá cho mục đích bảo vệ:

 Bằng chứng là “Olduvai Gorge” ở Trung tâm châu PhiVào khoảng 2.000.000 trước công nguyên (BCE)

"The Cradle of Mankind”

Giới thiệu (tiếp)

Dọc bờ sông Nile (cư dân Acập), sông Tigis (cư dân Hy lạp cổ), sông Ấn (cư dân Harappan), sông Vàng hay sông Hoàng

Hà (cư dân Trung Quốc cổ) đã xây nhà bằng gạch đất phơi nắng làm từ bùn và rơm rạ

Giới thiệu

Xây dựng ở thời kỳ La mã cổ đại (Romans): Thời kỳ là hoàng kim của xây dựng đã dùng: đá và khối xây, bê tông, gỗ và

kim loại:

vữa vôi dùng để xây các khối xây;

để tăng cường độ cho vữa và bê tông;

niệm về giàn, các giàn bằng đồng sử dụng tăng độ bền

và tuổi thọ

Giới thiệu

Thời kỳ tiền công nghiệp Hóa (18 th -19 th Century): Gạch đã

được sản xuất tại nhà máy, kính được sử dụng với khung kim loại:

một vài loại vôi có thể rắn trong nước Năm 1956, JonhSmeaton đã khám phá ra chất kết dính từ đá vôi cóthành phần đất sét có rắn chắc được trong nước

Parker và James Frost ở Anh đã nghiên cứu ra xi măng

từ năm 1756-1830 Năm 1824, Joseph Aspdin, gọi là ximăng Portland vì ông thấy có màu giống đá vôi ở đảo

Giới thiệu

Thời kỳ tiền công nghiệp Hóa (18 th -19 th Century):

1849 vă nhận bằng sâng chế năm 1867 Đê khuyếnkhích sử dụng đường sắt, ông dẫn, vòm mâi, cầu Vẵng cũng nhận bằng sâng chế về kết cấu dầm vă cột

được tiến hănh ở Mỹ (Ernest L Rasome), G.A Wayss ởĐức

Giới thiệu

Xây dựng thế kỷ thứ 20: Xây

dựng từ cuối thể kỷ thứ

19-đầu thế kỷ 20 các dạng kết

cấu nâng cao chiếm ưu thế.

Các dạng kết cấu này thường

sử dụng hoặc bê tông hoặc là

Giới thiệu

Xây dựng ngày nay – thời kỳ của Vật liệu tính năng cao : Từ năm 1980 thiết kế và xây dựng dùng ngày càng nhiều vật liệu tính năng cao và vật liệu để phát triển bền vững:

đường ôtô đã tài trợ cho dự án HPC năm 1987 vàChính quyền đường liên Bang (FHWA) cũng có cácchương trình quốc gia về bê tông chất lượng cao trongxây dựng cầu, cốt thép chất lượng cao (HPS) cho xâydựng cầu Thép chất lượng cao HPS-70W (Wearthing)

đã được dùng sớm từ năm 1996

Composite pôlyme gia cường (FRP) sợi ngày càngđược sử dụng phổ biến bởi những tính năng cơ họcđộc đáo và chống ăn mòn;

cấu lên 50-100 năm và làm giảm chi phí vòng đời củakết cấu

Cầu Confederation dài 12,9km, Canada (1997):

Cầu dầm hộp DUL dài nhất thế giới được xây dựng ở nước biển, 45 nhịp chính, chiều dài

Các tiêu chuẩn

Vật liệu tính năng cao phát triển theo xu hướng: Vật liệu sửa chữa hoặc vật liệu hoàn toàn mới Các tiêu chu#n, hướng dẫn thử nghiệm vật liệu tính năng cao ra đời:

concrete, T21, ASTM30.30.01 0

Serious Problem!!!

Greenhouse Gases? and Climate Catastrophe !!!

 A greenhouse gas (sometimes abbreviated GHG) is a gas in

an atmosphere that absorbs and emits radiation within the thermal infrared range This process is the fundamental cause of the greenhouse effect The primary greenhouse gases

in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects Greenhouse gases greatly affect the temperature of the Earth; without them, Earth's surface would average about 33 °C (59 °F) colder than

at present.

Back to the start

BÊ TÔNG CƯỜNG ĐỘ CAO,

BÊ TÔNG CHẤT LƯỢNG CAO

TS Nguyễn Thanh Sang

Industrial Waste, Agricultural Wasste

and Application.

Mineral

Admixtures

In Concrete

• Industrial, Argricultural Waste

• Fly Ash and Application

• Silicafume and Application

• Slag Cement and Application

• Metakaolin and Application

• Rice Husk Ash and Application

Industrial, Agricultural Waste

• Industrial waste is a type of waste produced by

industrial activity, such as that of factories, mills and mines

It has existed since the outset of the industrial revolution.

Much industrial waste is neither hazardous nor toxic, such aswaste fibre produced by agriculture and logging

• Agricultural waste which includes both natural (organic)and non-natural wastes, is a general term used to describewaste produced on a farm through various farming activities

• In the 21st century, one of the main challenges confronting theconcrete industry is to meet the enormous infrastructure andhousing needs of a rapidly inductrializing and urbanizing world

At the same time, there are concerns for high-energyrequirements and greenhouse gas (GHG) emissions associatedwith the manufacturing of portland cement Other concernsinclude inadequate durability of reinforced portland-cementconcrete structures There is also a growing public interest inecological and economic disposal of milions tonnes of industrialby-product that can be safely incorporated as cementitiousmaterials in concrete

Introduction - FLY ASH

• Fly ash, generated during the combustion of coal for energy production, is an industrial by-product which is recognized as an environmental pollutant Because of the environmental problems presented by the fly ash, considerable research has been undertaken on the subject worldwide.

• The term “Fly ash” is often used to describe any fine paniculate material precipitated from the stack gases of industrial furnaces burning solid fuels The amount of fly ash collected from furnaces on a single site can vary from less than one ton per day to several tons per minute.

Associate with Fly ash

Since wide scale coal firing for power generation began in the 1920s, many millions of tons of ash and related by-products have been generated The current annual production of coal ash world- wide is estimated around 600 million tones, with fly ash constituting about

500 million tones at 75–80% of the total ash produced [1] Thus, the amount of coal waste (fly ash), released by factories and thermal power plants has been increasing throughout the world, and the disposal of the large amount of fly ash has become a serious environmental problem The present day utilization of ash on worldwide basis varied widely from a minimum of 3% to a maximum of 57%, yet the world average only amounts to 16% of the total ash [1] A substantial amount of ash is still disposed of in landfills and/or lagoons at a significant cost to the utilizing companies and thus to the consumers.

Fly Ash

Fly Ash

High

High Volume Volume Fly Ash Concrete

ACI211.4 ACI211.4 2008 2008

ACI363 ACI363 2010 2010

Some action relative to Concrete

• For Sustainability

Evolution Concrete Technology

Corrossion Mitigation

Silica Fume

• Production of Silica Fume;

• Physical and Chemical Characteristics of Silica Fume;

• Physical and Chemical Mechanisms in the Cement–

Silica Fume System;

••

• Properties of Fresh Concrete;

• Properties of Hardened Concrete

• Durability Aspects

UsingSilica fume

in CONCRETE

Espectial inEspectial in

HPC

Silica Fume

• Production of Silica Fume;

– Silica fume is a by-product of the manufacture of silicon or ofvarious silicon alloys produced in submerged electric-arcfurnaces The type of alloy produced and the composition ofquartz and coal, the two major components used in thesubmerged-electric arc furnace, greatly influence the

submerged-electric arc furnace, greatly influence thechemical composition of silica fume (Malhotra et al., 1987).Most of the published data on the use of silica fume incement and concrete are related to silica fume collectedduring the production of a silicon alloy containing at least

75% silicon

Silica Fume

• Forms of silica Fume

– As-produced silica fume is silica fume collected in dedusting systems known as bag houses In this form, the material is

very fine and has a bulk density of about 200 to 300 kg/m3 , compared with 1500 kg/m3 for Portland cement (Malhotra

et al., 1987);

– Compacted (densified) silica fume: has a bulk density ranging from 500 to 700 kg/m3 and is considerably easier to handle than as-produced silica fume.;

– Water-based silica fume slurry: overcomes the handling and transporting problems associated with as-produced silica fume; the slurry contains about 40 to 60% solid

Silica Fume

• Color: Most silica fumes range from light to dark gray in color.

Because SiO2 is colorless, the color is determined by the nonsilica

general, the higher the carbon content, the darker the color of the silica fume The carbon content of silica fume is affected by many factors relating to the manufacturing process such as: wood chip composition, wood chip use versus coal use, furnace temperature, furnace exhaust temperature, and the type of product (metal alloy) being produced The degree of compaction may also affect the color.

• Density : Most silica fumes range from light to dark gray in color;

• Fineness : Surface area of approximately 20,000 m 2 /kg when measured

by the nitrogen-adsorption method; The mean particle diameter is 0.1

µm, compared with 10 µm for particles of cement.

Silica Fume (cont.)

ASTM C1240 and BS.EN 13263-1

Silica Fume (cont.)Physical Characteristics of Silica Fume

Silica Fume (cont.)Chemical Characteristics of Silica Fume

SF - Properties of Fresh Concrete

• Color: In general, the color of silica-fume concrete is darkerthan that of conventional concrete

• Water Demand: high specific area of the silica-fume particlestends to increase water demand;

• Bleeding: generally lower than that of plain Portlandcement concrete;

• Workability: Silica-fume concrete also tends to lose slumprapidly;

• Shrinkage Cracking: containing silica fume show little or nobleeding, thus allowing very little water to rise to the surface,the risk of cracking is high in fresh concrete

• Setting Time:

SF - Properties of Hardened Concrete

• Compressive Strength: contribute significantly to thecompressive strength development of concrete;

• Young’s Modulus of Elasticity: no significant difference;

• Creep: After one year, the creep strains of the reference, 7%silica fume, and 12% silica fume concretes were 1505 × 10–6 ,

713 ×10–6 , and 836 × 10–6 , respectively For concrete with 7%

713 ×10 , and 836 × 10 , respectively For concrete with 7%silica fume and 40% slag, the creep strain measured was thelowest at 641 × 10–6 ;

• Permeability: This decrease is much higher in concretesincorporating silica fume, due to its high pozzolanicity Planteand Bilodeau (1989) reported that the addition of 8% silicafume significantly reduced the penetration of chloride ions intoconcrete

• Role of Silica Fume in Reducing Expansion Due to Alkali–SilicaReaction:

Silica Fume in Concrete

Obtaining Silica

Silica Fume ConcreteFume Concrete

Slag Cement- Granulated Blast Furnace Slag

• Ground, Granulated, or Pelletized Blast-Furnace Slag:

Blast-furnace slag is a byproduct of iron manufacture When

it is rapidly quenched with water to a glassy state andfinely ground,it develops the property of latent hydraulicity

+ Should use Ground Granulated Blast Furnace Slag (GGBFS) in

concrete.

Because: GGBS concrete is characterized by high strength,

lower heat of hydration, and resistance to chemical corrosion

Prodution of Pig Iron and Blast- Slag

GGSFB - Properties of Fresh Concrete

• Mixture Proportions: the usual proportions vary from 25 to 50%

by weight of cement on a cement-replacement basis;

• Time of Setting: The incorporation of slag as a replacement forPortland cement in concrete normally results in increasedsetting time.

• Bleeding: a given mass of slag has a higher surface area than

• Bleeding: a given mass of slag has a higher surface area thanthe corresponding mass of Portland cement bleeding of slagconcrete will be lower than that of the corresponding controlconcrete

• Dosage of Air-Entraining Admixtures: The dosage requirement

of an air-entraining admixture to entrain a given volume of air

in slag concrete increases with increasing amounts of slag

GGSFB - Properties of Hardened Concrete

• Color: generally lighter;

• Curing: To ensure proper strength and durability of concretesincorporating high percentages of slag (>30%), it isimportant that they be given more curing than concreteswithout slag;

• Compressive Strength:The compressive strength development

• Compressive Strength:The compressive strength development

of slag concrete depends primarily on the type, fineness,activity index, and proportions of slag used in concretemixtures;

• Flexural Strength: increased because of the shape and surfacetexture;

Durability of Concrete Incorporating

Untilization

OF BFS and

its Engineering

Advantages

Utilization of Blast Funace Slag and Steel Slag

Highly Reactive Metakaolin

• Highly reactive metakaolin has recently become available as avery active pozzolanic material for use in concrete Unlike flyash, slag, or silica fume, this material is not a byproduct but ismanufactured from a high-purity kaolin clay by calcination attemperatures in the region of 700 to 800°C (Caldarone et al.,

1994) The material, ground to an average particle size of 1 to 2

µm, is white in color In 1994, a plant was commissioned inAtlanta to produce the material on a commercial scale

Hightly Reactive Metacaolin

• Chemical and Mineralogical Composition:

Unlike silica fume, which contains more than 85% SiO2 ,

highly reactive metakaolin contains equal proportions of SiO2and Al2O3 by mass Typical oxide analysis:

HRM - Properties of Fresh Concrete

HRM - Properties of Hardened Concrete

• Drying Shrinkage: The metakaolin concrete had a lower dryingshrinkage strain compared with that of the control and silica-fume concrete After 112 days of drying at a relative humidity

of 50%, the metakaolin concrete had a drying shrinkage strain

of 427 × 10–6 compared with 596 × 10–6 for the controlconcrete

HRM - Properties Durability Aspects

• Air-entrained concrete incorporating 10% metakaolin bymass of cement has high resistance to the penetration ofchloride ions and excellent durability in regard to repeatedcycles of freezing and thawing

RICE HUSK ASH - RHA

• Some vegetable wastes contain relatively large amounts

of silica One of the most promising examples is rice husk Since rice is a major crop among many of the developing countries, it is available in large quantities.

• Rice husk is an agricultural residue obtained from the

• Rice husk is an agricultural residue obtained from the outer covering of rice grains during milling process Current rice production in the world is more than

700 million tons Rice husk constitutes about 20% of the weight of rice It contains about 50% cellulose, 25– 30% lignin, and 15–20% of silica.