What are the advantages of compacting the concrete?
The main advantages of self compacting concrete are:
- The permeability of the concrete structure is decreased.
- SCC enables freedom in designing concrete structures.
- The SCC construction is faster.
- The problems associated with vibration is eliminated.
- The concrete is placed with ease, which results in large cost saving.
What are the advantages of self consolidating concrete?
Self-leveling, self-consolidating concrete reduces the labor required to place and finish it. It eliminates mechanical vibration and reduces screeding, Eliminating vibration in precast production settings reduces noise. In an urban setting, decreased noise may even allow for longer construction hours.
Under what circumstances is self compacting concrete?
Self-compacting concrete (SCC) is a special type of concrete which can be placed and consolidated under its own weight without any vibration effort due to its excellent deformability, and which at the same time is cohesive enough to be handled without segregation or bleeding.
Is self compacting concrete expensive?
But its initial higher supply cost over conventional concrete, has hindered its application to general construction. Cost analysis showed that the cost of ingredients of specific self compacting concrete mix is 35.63% less than that of control concrete, both having compressive strength above 34 MPa.
What is the difference between self compacting concrete and normal concrete?
The compressive strength developed for SCC and normal concrete for same water-binder ratio are similar. The value of split tensile strength is higher in SCC compared to normal concrete. The modulus of elasticity of self compacting concrete is low compared when compared to normal concrete.
How do you build a self compacting concrete?
A simple tool has been designed for self compacting concrete (SCC) mix design with 29% of coarse aggregate, replacement of cement with Metakaolin and class F flyash, combinations of both and controlled SCC mix with 0.36 water/cementitious ratio(by weight) and 388 litre/m3 of cement paste volume.
How do you test for self compacting concrete?
Test methods to determine workability of Self Compacting Concrete are:
- Slump flow test. The slump flow test is used assess the horizontal free flow of self compacting concrete in the absence of obstructions.
- V Funnel Test. Ad.
- L Box Test.
- U Box Test.
- Fill Box Test.
What are the qualities of ingredients in self compacting concrete?
The three properties that characterise a concrete as self-compacting Concrete are Flowing ability—the ability to completely fill all areas and corners of the formwork into which it is placed Passing ability—the ability to pass through congested reinforcement without separation of the constituents or blocking Resistance …
Is code for self compacting concrete?
This paper deals with the Mix design of Self-Compacting concrete. The highlight of this paper is, simplest process of Mix design according to Indian Standard Code of Mix design (IS-10262) and It follows all the design conditions in line with Indian Standard Code of Reinforced Concrete Structure (IS:456).
Which admixtures are used in self compacting concrete?
Commonly used superplasticizers are sulfonated melamine formaldehyde condensate (SMF), sulfonated naphthalene formaldehyde condensates (SNF) and polycarboxylate ether-based superplasticizers (PCE). The setting accelerators and hardening accelerators are two main types of accelerators.
How do you test concrete flow?
Conducting the test Each layer is tamped 10 times with a tamping rod. Wait 30 seconds before lifting the cone. The cone is lifted, allowing the concrete to flow. The flow table is then lifted up 40mm and then dropped 15 times, causing the concrete to flow.
What is a good concrete slump?
Four-inch
What is a 5 slump in concrete?
The 4- to 5-inch slump for decorative concrete is a relatively stiff mixture, but not quite as stiff as the 2- to 3-inch slump seen here. A higher slumped concrete is more more fluid and will flow some distance on its own.
What is the average slump of concrete?
What is true slump test?
True slump refers to general drop of the concrete mass evenly all around without disintegration. It may undergo segregation and bleeding and thus is undesirable for the durability of concrete. Collapse slump indicates that concrete mix is too wet and the mix is regarded as harsh and lean.
What is the true slump value?
What is the ideal value of slump? Answer 1 In case of a dry sample, slump will be in the range of 25-50 mm that is 1-2 inches. But in case of a wet concrete, the slump may vary from 150-175 mm or say 6-7 inches.
What is a positive slump test?
Results. Positive sign is any kind of sciatic pain (radiating, sharp, shooting pain) or reproduction of other neurological symptoms. This indicates impingement of the sciatic nerve, dural lining, spinal cord, or nerve roots.
What’s a slump?
Slump is a slang term for a sharp decline in business activity, trade, or market values. Slump is a very flexible term in that it is used to describe both a short, sharp decline as well as a more gradual, prolonged period of low activity or value. In economic terms, slump usually refers to the beginning of a recession.
Why is concrete consistency important?
Why do a concrete slump test? Understanding the consistency of your concrete mix is useful for several reasons. Essentially, it allows you to preview what your concrete will be like before it sets, allowing you to make adjustments to the mix to create a better product with more favourable consistency.
How is concrete tested for strength?
Compressive strength of concrete Compressive strength is tested by breaking cylindrical concrete specimens in a special machine designed to measure this type of strength. It is measured in pounds per square inch (psi). Testing is done according to the ASTM (American Society for Testing & Materials) standard C39.
What is the meaning of consistency in concrete?
Consistency refers in a general way to fluidity or workability and can be defined by such terms as dry, plastic, fluid, or wet. Slump is a more specific term for one kind of measurement of concrete consistency.
What are the different slump for concrete?
Very dry mixes having slump 0 – 25 mm are typically used in constructing pavements or roads, low workability mixes having slump 10 – 40 mm are typically used for foundations with light reinforcement, medium workability mixes with slump 50 – 90 mm, are typically used for normal reinforced concrete placed with vibration.
What are the 4 types of slump?
What is slump & It’s types, Values for various construction work
- Collapse slump : In this case, fresh concrete collapses completely.
- Shear Slump: If one-half of the cone slides down in an inclined plane, it is called a shear slump.
- True Slump: Mix has high stiff consistency.
How much Slump do you need for a slab?
A good slump for most flatwork placed by hand: five inches. For slabs struck off with mechanical equipment: two to four inches.
What is the maximum concrete slump?
between 2 and 5 inches
Does higher PSI concrete crack less?
adding more cement increase the psi and its more resistance to bending by load factors, less cracking.
What PSI should my concrete driveway be?
3000 psi to 4000 psi