Civil Engineering - Concrete Technology - Discussion

5. 

For given water content, workability decreases if the concrete aggregates contain an excess of

[A]. thin particles
[B]. flat particles
[C]. elongated particles
[D]. flaky paticles
[E]. all the above.

Answer: Option E

Explanation:

No answer description available for this question.

Hari said: (Aug 8, 2013)  
All are the particles have insufficient capability to increase workability.

Nwaeze, Humphrey said: (Jan 18, 2014)  
The answer E because all of them are debris i.e unwanted particles, which absorb water thereby decreasing the water content.

Sanj said: (Apr 14, 2014)  
Rounded shape of the aggregate is best for high workability.

Jairaj said: (Apr 17, 2014)  
Rounded shape of the agrt are not suitable for any kind of concrete structure. Because there will not have grip between the concrete constituents.

Ruturaj Kurade said: (Jun 11, 2014)  
This type of particle is lead to reduce workability because surface area is more of these particle.

Srinu said: (Jul 5, 2014)  
Triangular shape of aggregate is best for high workability.

Ahir Ashok R said: (Jul 6, 2014)  
Rounded shape particles are the most suitable for the high workability.

Soni Kumari said: (Sep 10, 2014)  
Rounded shape particles are the most suitable for the high workability.

Shubham said: (Sep 14, 2014)  
Rounded shape particles are the most suitable for the high work-ability, but Triangular shape of aggregate is best for high strength b/c of good bonding between cement paste and aggregates.

Dini said: (Feb 11, 2015)  
How surface area is depended on work ability?

Devidas Bedre said: (Apr 23, 2015)  
This type of particle lead to reduce work ability because there is formation of voids between them therefore there will not have grip between the concrete constituents.

Pradeep said: (Apr 30, 2015)  
Angular shape particle is use in concrete because this shape is good for aggregate.

Mike said: (May 25, 2015)  
Because the surface is dependent on work ability.

Deepak said: (Jun 2, 2015)  
@ Dini.

I think more surface area absorb more water at given water content so reduces workability.

B Bikshapathi said: (Jun 16, 2015)  
I think angular aggregate are more useful for construction because it gives more work ability.

Tony said: (Aug 9, 2015)  
The more the surface are the more cement paste required for enveloping them. So as flaky, elongated particles have more surface area less cement available, less cohesion, more segregation.

Satani Mohit said: (Nov 6, 2015)  
I think elongated aggregate are more than useful for construction. Because is more than strength and work ability and structure life is many more years.

Pallabi Rath said: (Dec 16, 2015)  
Surface area as decreases strength decreases but work ability increases. So round gives more work ability but less strength and flaky elongated material gives less work ability and more strength.

Irfan said: (May 27, 2016)  
Yes @Deepak.

The more surface area absorbs more water at the given water content so, it reduces the workability.

Adil Hussain said: (Aug 6, 2016)  
Surface area is more for all types of aggregate in this. So the answer is E.

Suraj said: (Aug 10, 2016)  
Rounded shape particles are the suitable for the high workability.

Hitendra said: (Sep 12, 2016)  
The aggregate with rounded shape has the minimum percentage of voids ranging from 32 to 33%. It gives the minimum ratio of surface area to given volume and hence requires minimum water for lubrication. It gives good workability for the given amount of water and hence needs less cement for a given water cement ratio. The only disadvantages are that the interlocking between its particles is less and hence the development of bond is poor. This is why rounded aggregate is not suitable for high strength concrete and for pavements subjected to tension.

Vipin said: (Dec 26, 2016)  
As per IS - 383, The aggregate should be angular.

Naren said: (Jan 15, 2017)  
Workability decreases if the concrete aggregate contain above options bcoz, surface area is high.

Rounded and semi-rounded aggregates increases workability because for a given volume it has less surface and less void, so excess paste is available to give better lubricating effect and rounded aggregates has less friction resistance.

Important nature of workable concrete is its lubricating nature.

Chinny said: (Feb 11, 2017)  
I think the angular shaped aggregates are more used construction & it gives more strength, w workability.

Duraisamy said: (Apr 5, 2017)  
Water cement ratio indirect proportion to the size of practical and workability.

Ajay Desai said: (Nov 22, 2018)  
Rounded shape particles are the most suitable for the high work-ability, but angular shape of aggregate is best for high strength b/c of good bonding between cement paste and aggregates.

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