Regarding Slump checking.

[VIDHYA SAGAR]

Our design mix slump is 120 +/- 25mm.

Our client asking to show the slump at Pumping point.

We are pumping the concrete to 15th floor.

If i am showing slump at pumping point, I am getting around 50 to 60 mm only at pouring area due to pipe friction etc.

It is very difficult for workers to pull the concrete and for this we are facing honeycomb problem also.

If i am keeping slump as collapse at pumping point, then i can get around 120 mm slump at pouring point.

Client is arguing that the design mix to be changed other wise, to keep slump 120 +/- 25 at pumping point.

I explained that, while doing Trial mix, we are noticed as collapse at initial observation and the slump 120 +/- after 2 hours only.

My question is where we need to show the slump reading?

It should be at pumping point or pouring point?

Any IS Clarification please.

Thanks.

Vidhyasagar.

 

[Dnyan Deshmukh]

I think your client Engineer must be a fresher or does not understand anything about concreting or may had experience of ageing type (just working from long period and does not have any knowledge).

Your client engineer may not be a engineer but yes he might be a Supervisor, who does not understand friction losses or might not be even aware of anything in construction industry as few peoples are lucky who rises to top without actually working or having knowledge about somethings.

the requirement of the slump or workability is given for placing of concrete in place base on the structure shape, rebar details and ease of doing it.

It is not something which need to satisfy someones eye who is standing on ground at pumping location and expecting the value should be same at ground as it is written in design.

First of all, kindly do understand the need of client, what he is trying to specify you;

if you find the client is fool and demanding something which is beyond scope of normal concrete for which you quoted.

Do a new trials with high range water reducer admixture PC based, and submit the report along with increase in cost per cum for doing that type of concrete.

This is the simplest solution to satisfy the someone who is acting as a smart and also to get rid of issues which are getting created unnecessarily.

Increase in cost due to foolishness of someone will make him highlighted in his organisation and you know further what happens.

You can show this answer to your client to make him realization of ground reality.

Engineers do work like fool when they does not understand anything about things which they handle, when i was fresher, even though i was working in contracting company, i too use to ask silly questions and screwing my seniors saying something is wrong and we need to stop the work.

Unless and until we start observing things, how they happen or why there are criteria, we never going to learn any thing and our knowledge will always be like a fool who does not know the ground reality.

 

[VIDHYA SAGAR]

Thanks for your reply.

As a client they are asking for IS codes references for every thing like the above issues also.

Simply telling that "show me in IS Code",,,

Argument is not solution and it leads to ego issues.

Wrote mail to QC Manager to solve such issues...

Sorry for disturbed you in this regard.

 

[Dnyan Deshmukh]

Thanks for your reply.

As a client they are asking for IS codes references for every thing like the above issues also.

Simply telling that "show me in IS Code",,,

Argument is not solution and it leads to ego issues.

Wrote mail to QC Manager to solve such issues...

Sorry for disturbed you in this regard.

You can also ask client to show me what you specified in your specifications.

Client company always do specify the requirements or in case if they do not have any specifications then contractors can carryout work as per IS Codes specifications.

Your client might had understood the concept of workability.

Kindly show him the defination of workablility to make him understand wht it is.

 

[protin]

Ease of doing work while maintaining optimum water cement ratio and slump value should be kept in mind and certain permissible limit should be allowed so as to make the Pouring of concrete easy without losing its designated compressive Strength. But maintain optimum slump if you are using vibrator.

 

[ARAVINTHRAJ]

thank you for your details ,
kindly send thumb rules

 

[Srinivasan]

There is no thumbrule for slump.why engineers talk about the thumb rule.i can't understand.if I translate thumb rule in Hindi it says angutta chap
I think engineers are professional
Balance up to u

 

[ARAVINTHRAJ]

Friend I'm talk to general thumrule all activity .that not mention for slump

 

[Srinivasan]

Kindly refer the forum in depth and understand.all thumb rule is available in the forum

 

[Akash 2]

Sir I am facing same problem. Our Batch 120m away from construction building.. while I am slump testing on pouring point 100 will get it is difficult to pull concrete. Suppose w/c variation is done strength will variation..

 

[Dnyan Deshmukh]

Sir I am facing same problem. Our Batch 120m away from construction building.. while I am slump testing on pouring point 100 will get it is difficult to pull concrete. Suppose w/c variation is done strength will variation..

To get a desired workability of concrete, concrete need to be designed.

If the distance of the concrete plant from pouring location is more and also required more retention time (slump for longer time) selection of admixture plays important role in it.

Using admixture we can increase the workability of concrete without increasing water cement ratio.

 

[MUKUNDA1994]

How much slump required in pumping point in that case

 

[furkan56]

1.2% works well