Properties of Fresh Concrete | For Best Construction

in this post learn about properties of fresh concrete, this properties help us to understand good quality of concrete. this post is design for students, for exam point of view which helps to understand properties of fresh concrete also, we learn about factors affecting on workability , water content , mix proportion , size of aggregate, shape of aggregate , grading of aggregate , surface texture and Use of admixture.

Important properties of fresh concrete are as follows

Workability of Fresh Concrete

Workability of concrete –

On thematical water cement ratio calculate Faso the concentration discuss in provirus. chapter is not going to give an ideal situation For max Strength 100% compaction of Is on imp. parameter For cantibrte for max strength lack of compaction will result in air voids whose damage in effect on strength & durability is equally or move predominal presence of capillary cavities .

To enable the concrete to be fully competed with given efforts .normally higher cement water ratio than that calculated by therotical  consideration

that is to say the Fauction of water also to lubricate the Concrete so that concrete can be compacted with specific efforts Coming at the compacting with amount of essents forth. Coming to finish it sufficiently easily the presence of creation quantity of Water.

The quality of concrete stratify the above requirement is term as workable concrete. The word   workability “workable Concrete” significance much wider and deeper meaning that other terminology “Consistence” obtain used rear workability consistency is a general term to indicate the degree of fluidity of degree of mobility the Concrete which has high consistency and which is more mobile need not to be have right workability for concrete design technologist compressive knowledge workability.

What is the most important property of fresh concrete?

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Factor Affecting workability

Following are the factor helping the concrete to be more grease and ease in compaction.

Water content for Fresh Concrete

1. Water content in the concrete has significance influence on the workability.
2. Higher the water content per cubic meter of concrete, higher will be the fluidity of concrete, which is one of the important factor affecting the workability.
3. Water is required to chemically react with cement and to give the workability to concrete so that it can be placed and compacted to the desired shape.
4. Generally, water required to be added for cement hydration is very less as compared to water required for workability.
5. But it should be noted that from the point of desirability, the increase in water content is the last alternative to be taken for improving the workability.
6. More water can be added, provide that the higher quantity of cement is also added to maintain the required water content ratio so that the strength and durability will remind the same.

Mix Proportion for Fresh Concrete

1. The aggregate occupancy approximately 70 to 75 percent of the total volume of concrete and economic demand that the volume of aggregate should be as larger as possible
2. The higher the aggregate / cement ratio the learner is the concrete .
3. In lean concrete least or less quantity of poste is available For providing lubrication.
4. per unit surface area of aggregate and hence the rigidity of aggregate is retained.

Size of aggregate for Fresh Concrete

1. The bigger size of the aggregate. 
2. For the same volume of aggregate in concrete the use of course aggregate of larger size or rounded aggregate gives higher  workability because of reaction in total surface area and particle in interference.
3. To reduce internal friction, For a given quantity of water and poste bigger site Of aggregate will live higher workability.
4. The use of finals and increase the surface area there by increasing the demand of water for the same workability resulting in the decreases workability.

Shape Of aggregate for Fresh Concrete

1. Angular, elongated or flaky aggregates makes the concrete very harsh than the rounded or cubical shaped aggregates.
2. This is because that for the given volume or weight it will have less surface area and less voids than angular or flaky aggregates.
3. Also being round in shape the frictional resistance will also reduce.
4. This explains the reason why river sand and gravels provide greater workability to concrete than crushed sand and aggregates.

Surface texture for Fresh Concrete

1. The rough textured aggregates gives the more surface area than the smooth rounded aggregate of same volume.
2. Therefore, as discussed earlier the rough textured aggregates will show poor workability.
3. The reduction in the frictional resistance offered by smooth aggregates between the particles or formwork results in the higher workability.

Grading of aggregates

1. Grading of aggregate will have the maximum influence on the workability.
2. The proportion of fine to coarse aggregate should be so chosen as neither to increase the total surface area (by excess of fine aggregate) nor to increase the particle interference (due to deficiency in fine aggregate).
3. Aweil graded aggregate is the one which has least amount of voids in a given volume. When the total voids are less, more paste is available to give better lubrication to concrete.
4. With excess amount of paste, the mix becomes cohesive and fatty which prevents segregation of particles.
5. Also there will be reduction in interparticle frictional resistance which leads to the higher workability.
6. Therefore better the grading of aggregate, the less is void content and higher the workability.

Use of admixture

1. Use of admixture or cement replacement will affect the workability considerably.
2. The plasticizers and superplasticizers greatly improves the workability of concrete.
3. Use of air-entraining agent reduces the internal friction between the particles.
4. It can be viewed that the air bubbles formed due to use of air-entraining agent act as a sort of ball bearing between the particles, reducing the inter particle frictional resistance and gives mobility to the particles.
5. Fine pozzolanic materials offers better lubricating effects for giving better workability.

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Important links

1. Why AAC Blocks are a Smart Choice for Construction
2. 15+ types of admixtures used in concrete
3. cement and types of cement