Question

Topic: Self-Compacting Concrete

Submit a preliminary abstract, introduction and list of references

Answer 1

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Topic: Self Compacting Concrete- Abstract, Introduction and list of references

SELF COMPACTING CONCRETE – A REVOLUTIONARY BUILDING MATERIAL.

ABSRTACT:

Self-compacting concrete (SCC) is defined as concrete that can be placed normally andwill flow under its own weight while maintaining its homogeneity. Full compaction andstrength may therefore be achieved without the assistance of mechanical vibration. Itsdevelopment was based on the desire to improve the quality of concrete work andautomate construction. It was developed in 1988. Since then, various investigations have been carried out and mainly large construction companies have used the concrete in practical structures in Japan. Here in this report an attempt has been made to study thecharacteristics of self-compacting concrete and the specialties in the mix design, whichhad given it the self-compacting capacity.

INTRODUCTION:

Self-compacting concrete refers to a special type of concrete that can be compacted toevery corner of the formwork, purely by means of its own self-weight and without theneed for vibrating or compaction. Scc is self-compacting itself alone due to its own self weight and it is characterized by high segregation resistance. The need for self compacting concrete is particularly because conventional concrete tends to present a problem with regard to inadequate consolidation in thin sections or areas of congestedreinforcements, which leads to a larger volume of entrapped air and compromises thestrength and durability of concrete.SCC was developed initially in Japan in the 1980s when contractors were experiencing asevere shortage of skilled manpower. Due to its inbuilt assurance of uniform placementand full compaction it is now becoming a revolution in concrete technology.

2. REQUIREMENTS OF SCC:

SCC mixes must meet three key properties:

1. Ability to flow into and completely fill intricate and complex forms under its ownweight (flow ability)2. Ability to pass through and bond to congested reinforcement under its own weight-(pass ability).3. High resistance to aggregate segregation-(segregation resistance).

SCC requires some special considerations in mix proportioning

1. It may be useful to keep in mind three important features of SCC over and above theusual factors, which influence the design of normal concrete.

2. The required flow ability achieved with the help of super plasticizer.

3. The cohesiveness or viscous ness of the mixture ensured by increased powder contentand reduced coarse aggregate content.

4. Stabilizing agents (viscosity modifying agents) are usually needed so that smallchanges in water content do not adversely affect the cohesiveness of SS

# REFERENCE:

EFNRC, specification and guidelines for self-compacting concrete, February 2002.Jagadesh vengala and R.V Ranganath (August 2004),Mixture Proportioning ProceduresFor Self Compacting Concrete, Indian Concrete Journal,.P.Kumar Metha (June 1997) Concrete Microstructure ,Properties And Materials,page no381 to 393.S. Nagataki (1995), Self Compacting Property Of Highly Flowable Concrete, AmericanConcrete Institute, sp 154 , page no. 301 to 304.