Use and benefits of self compacting concrete

Self-consolidating concrete alias self-compacting concrete (SCC) is a concrete mixture that can flow into very complex forms with various reinforcing bars (rebar congestion) and leaves no voids.

It can be arranged with its own weight devoid of any mechanical vibration. SCC retains all the conventional mechanical and durability characteristics of concrete.

With extremely fluid nature of SCC, it becomes possible to arrange it in complicated conditions and in sections with congested reinforcement. It can also reduce hearing-related damages on the worksite due to vibration of concrete. In SSC, the required time is curtailed significantly for arranging bigger sections.

In some cases, the superplasticizers and viscosity modifier are provided to the mix to minimize bleeding and segregation.

A well designed SCC mix never segregates because it contains extreme deformability and outstanding stability characteristics.

Self-Compacting Concrete Properties: Self-compacting concrete has good resistance capacity against segregation as it applies mineral fillers or fines as well as special admixtures. Self-consolidating concrete is essential to flow and fill special forms under its own weight. It is flown adequately to travel over extremely reinforced areas, and should have capability to circumvent segregation of aggregate.

Self-compacting concrete contains an equivalent water cement or cement binder ratio that provides normally a slightly higher strength with regards to conventional vibrated concrete and because of non-existence of vibration, a better interface among the aggregate and hardened paste is created.

The concrete mix of SCC should be arranged at a comparatively greater velocity as compared to regular concrete. Self-compacting concrete is placed from heights longer than 5 meters exclusive of aggregate segregation. It is also useful for areas having normal and congested reinforcement, with aggregates as large as 2 inches.

Self-Compacting Concrete Uses - Self-compacting concrete is mostly utilized in bridges and even on pre-cast sections. This type of concrete is suitable for the following:

• Drilled shafts
• Columns
• Earth retaining systems
• Areas with high concentration of rebar and pipes/conduits

To know about the benefits of self consolidating concrete, go through the following link thebalance.com



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Published By
Rajib Dey
www.constructioncost.co
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Basic differences between Mortar and Concrete

Concrete and mortar are two most vital building elements for any construction work. But both the materials are different in nature. Go through the following article to know the fundamental discrepancies among concrete and mortar.

Concrete:

Concrete is a composite material produced from a mixture of sand, cement, aggregates and water in required proportions.

Concrete refers to a composite material that is formed with some basic elements like water, aggregate (rock, sand, or gravel) and amalgamated with a fluid cement that hardens in due course.

If aggregate is combined jointly with dry Portland cement and water, it produces a fluid mass that can be smoothly molded into shape. A chemical reaction happens between cement, water and other ingredients to develop a hard matrix that joins the materials together into a strong stone-like material.[2] Sometimes, additives like pozzolans or superplasticizers are provided in the mixture to make the physical properties of the wet mix or the finished material superior.

Mortar:

Mortar is developed by mixing cement, sand and water and applied to tie building blocks like stones, bricks, and concrete masonry units jointly as well as fill and close the uneven gaps among them.

VARIANCE AMONG MORTAR AND CONCRETE:

1. Concrete is developed by mixing cement, sand, aggregates and water, whereas the mortar is formed by mixing cement, sand and water.

2. Concrete is more durable as compared to mortar.

3. The water-cement ratio is greater in mortar. The water is utilized to hydrate the cement and retain the mix collectively. But the objective of concrete is to maintain the water-cement ratio as low as possible.

4. After mixing, Mortar becomes much condensed substance as compared to concrete. Mortar acts like a glue to fix the bricks together. Because of superior strength and longevity concrete is mostly recommended for all types of construction works like buildings, bridges, roads etc.

5. Concrete sustains for a long time but mortar should be substituted by every 20 – 30 years.

Article Source : www.dailycivil.com

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Published By

Rajib Dey

www.constructioncost.co

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Mix Design On The Basis Of Dry Condition

Ascertain or Identify Slump Value

The initial step is to identify the lowest and highest limit for slump of concrete that has been utilized. Often the designer identify slump for concrete mix, this is correctly based on some conditions, otherwise if the value of slump is not indicated Table 1 is applied to find out the lowest and highest slump value on the basis of the type of structure.

Note: The value of (Table 1) is dependent on applying vibrator for compaction of concrete, if there is other method for compaction like a tamping by rods or other method add (2 cm) for every selected value from table 1.

Step 2: Ascertain or State Maximum Aggregate Size

Highest Aggregate Size is considered as the most vital data to be ascertained or identified for their mix design. This value is acquired from sieving analysis test result of coarse aggregate. Coarse aggregate must be examined prior to utilize in concrete mixture preparation. This value is accessible even for comprehensive mix design process.

Value of Maximum Aggregate Size must be examined with the following three equations:

(a): Highest Aggregate Size must be identical or lesser than 1/5 (lowest distance among form work side).

(b): Highest Aggregate Size must be identical or lesser than 1/3 (thickness of concrete member).

(c): Highest Aggregate Size must be identical or lesser than 3/4 (slightest distance among reinforcement).

Note: Point (c) is very vital in checking process as if the aggregate size exceeds the spacing of reinforcement while casting, concrete fails to pass the rebar cage. It signifies that passing ability of concrete is considerably reduced.

To read the complete article, visit ge4c.com

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Published By

Rajib Dey

www.constructioncost.co

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