Self Compacting Concrete Vs Conventional Concrete

This post differentiates between Self compacting concrete and Conventional Concrete.  What is SCC and what are its Advantages over Conventional Concrete??

Why it’s good to use SCC and where?? You will find out all these answers in this article, to know more continue reading…….

 Introduction

Concrete is the one of most important part of construction or even civil engineering. Concrete is of different types, each having its own properties and advantages as per its functions. Here we will discuss two of them Self Compacting Concrete and other one is the Conventional Concrete. Both of them are suitable for different conditions which will be described ahead.

Self Compacting Concrete

Self Compacting Concrete becomes an alternative replacing the conventional slump concrete because of many conditions in present construction field. Major factors leading to increasing use of SCC will be Cost Saving and Performance enhancement of project.

“Self Compacting Concrete” or “Self Consolidating Concrete” is highly flow-able, non-segregating concrete that can spread into place, fill formwork and flow through densely reinforced complex structural elements under its own weight and adequately fill all the air voids with the help of segregation without needing mechanical consolidation or vibration process.  

SCC is the concrete having properties that differ considerably from conventional slump concrete. There is a little confusion under which Highly Flowing Concrete (HFC) and Self Compacting Concrete (SCC) are categorized as same things. But actually both of the terms has a lot of difference. Flowing concrete is the concrete having slumps greater than 190 mm 
(7 ½ inch.) while maintaining cohesive nature also. This means that this kind of concrete is capable to attain a leveled surface with little effort by the placer, but so leveled surface also requires vibration for removal of air voids so produced. Whereas SCC doesn’t requires vibration for the purpose of the void removing. This means that SCC is always highly flowing concrete (as an property) but Highly Flowing Concrete (HFC) may not qualify as SCC.

How SCC is Different from Conventional Slump Concrete??

 

SCC must be highly workable so that it can move under the force of gravity without vibration, during mixing, transportation, handling, and placement. It is so highly flow able that the conventional slump test cannot distinguish between different levels of SCC flow ability (all would be 280 mm + in sump). However SCC must also be viscous enough so that the mortar suspends and carries the coarse aggregates also with it. It would be able to maintaining homogenous and stable mixture, resistant to segregation, excessive air migration. It must have dynamic stability during mixing, transportation, handling and placement. While Conventional Slump Test is carried out on Conventional Slump concrete then the samples brought to 280 mm does not have stability.    

Reasons for Increasing Usage of SCC

 

The contractors and owners are highly pressured to produce better quality construction at lower costs of labor, material and equipments. The economic benefits of the less intensive construction environment results in labor saving, time saving and greater flexibility of design. SCC provides followings :-

• Reduces in place cost.
• Improved work environment and safety.
• Improved aesthetics.

Limitations of SCC

• APPLICATION- it must be used properly while using in a flat work, because it has limited bleeding characteristics which may cause shrinkage, cracking.
• PRODUCTION AND QUALITY CONTROL- it needs a higher level of production and quality control as compared to conventional slump concrete.

Parameters of Successful SCC

• Coarse aggregate content must be 28% to 38% of concrete volume.
• Paste Friction must be 35% to 37% of the mix.
• Fine aggregate must be 45% to 55% of the Concrete volume.
• Water content must be controlled properly as per admixtures.
• Air content must be as needed for the durability because air can improve the viscosity of mix and increase its volume.

At last we can say that SCC is the one most useful type of concrete specially when we are in time consuming conditions. There are many of industry organizations working on specifications, test methods and practices of SCC. As new information will be available, updates will be added to this article. 

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