Group # 1

2013-BT-Civil-01 Muhammad Aamir2013-BT-Civil-25 Suphvan Azhar

High performance concrete

Contents• Introduction• Definition• History• Properties• Why HPC is important?• HPC used in structures• Setting time• Durability characteristics• When to use HPC?• Benefits• Types of HPC• Limitations• Conclusions• Question Answer Session

Introduction

 High performance concrete is a concrete mixture, which possess high durability and high strength when compared to conventional concrete. This concrete contains one or more of cementious materials such as fly ash, Silica fume or ground granulated blast furnace slag and usually a super plasticizer. . The use of some mineral and chemical admixtures like Silica fume and Super plasticizer enhance the strength, durability and workability qualities to a very high extent.

Definition

• Any concrete which satisfies certain criteria proposed to overcome limitations of conventional concrete may be called as high performance concrete .

• It may include concrete which provides either substantially improved resistance to environmental influences OR substantially increased structural capacity while maintaining adequate durability.

HPC

Concrete may be regarded as high performancefor several reasons

• High strength

• High workability

• High durability

• Also improve visual appearance

History of concrete

• During Roman empire Roman concrete was made from quicklime, ash and an aggregate of pumice. It quickly hardened into a rigid mass, free from many of the internal thrusts and strains which trouble the builders of similar structures in stone or brick. Modern tests show Roman concrete to be as strong as modern Portland cement concrete.

properties

• Ease of placement• Compaction without segregation• Early age strength• Long term mechanical properties• Permeability• Density• Toughness• Volume stability• Long life in severe environments

Why is Hpc important? Concrete is the most widely used building material.

any improvement in the design of this material e.g. cost, durability, or strength ripples through the economy. HPC is a specialized series of concretes designed to provide several benefits in construction of concrete structure.

Hpc used in structures

Setting time

                Setting time can vary depending on the application and the presence of set modifying admixtures and percentage of the paste composed of Portland cement. The use of large quantities of water reducing admixtures can significantly extend setting time

Durability characteristicsThe most important property which distinguish HPC from conventional concrete. This is due to the refinement of pore structure of microstructure of the cement concrete to achieve a very compact material with very low permeability to ingress of water, air, oxygen, chlorides, sulphates and other deleterious agents.

WHEN TO USE HPC

                     High Performance Concrete can be used in severe exposure conditions where there is a danger to concrete by chlorides or sulphates or other aggressive agents as they ensure very low permeability.

Performance benefits Cost& other benefits

• Ease of placement and consolidation without affecting strength

• Long term mechanical properties

• Early high strength• Toughness• Volume stability• Longer life in severe

environments

• Less material• Fewer beams• Reduced maintenance• Extended life cycle

Types of hpc

1. Toproc CR – Chemical Resistant concrete

2. Toproc ED – Early Drying concrete

3. Toproc UW – Ultra Water resistant concrete

4. Toproc HR – Heat Resistant concrete

5. Toproc SY – Impact and abrasion resistance

LIMITATIONS 

• Concrete can be damaged at very high temperature.• High Performance Concrete has to be manufactured

much more carefully than normal concrete.• An extended quality control is required• In concrete plant and at delivery site, additional tests

are required. This increases the cost• Some special constituents are required which may

not be available in the ready mix concrete plants.

Conclusion

• HPC become a crucial element of the viability of tall buildings in the region

• High strength to reduce the size of sections

• High durability makes it much important

• It enhance visual effect

• It can bear severe environments

THANKS FOR YOUR ATTENTION