Sikament LN Problems 1

[ditapark]

Hello everyone, I'd like to ask you regarding Sikament LN, which known as water reducer and will accelerate the hardening process of the concrete. I'm doing a research where I need to use 2% of Sikament LN to add to the concrete admixture. While making the admixture, I got some problems which are;
1. I'm using 2% of Sikament LN with reducing the water-cement ratio (WCR) to 5% - 20% and above, and when I'm making the admixture with reducing the WCR to 5%, the admixture hardly harden in 24 hours time, and it need at least 5 days to hardening. At first we thought it was because we use too much WCR, but when we reducing the WCR up to 15% we got the same problem as well, where the admixture wasn't fast enough to set(harden).
2. When we open the mould, the concrete has cavities all over, and because of that the quality of the concrete decreased.

Some of the people around assumed the Sikament LN that we used was expired, but we just bought it and it still fully sealed when we first bought them. From what I know, the use of 2% of Sikament LN is not exactly right, because they only recommend the use of Sikament LN up to 1,5%.

My question is,it said that Sikament LN will help the hardening process of the concrete, but in reality, the using of Sikament LN makes the hardening process of the concrete became slower than the hardening process without using Sikament LN, why that happen?

And is it possible for Sikament LN to be expired? If yes, could you explain more about characteristic features of the expired Sikament LN?

I'm really sorry for asking too much, but I really desperately need help about this, and if you don't mind could you give me some book recommendation regarding this problem as well?

I couldn't thank you enough.

Sincerely,
Dita.

 

[MotorCity]

I think you would get a better response by contacting sika instead of relying on answers from the internet (unless any sika reps happen to troll these forums)

 

[Ron]

Would you post a copy of your mix design here? That would help us to give you reasonable feedback.

 

[ditapark]

@Ron
Here's my job mix design based on Indonesian National Standard (SNI)

Thank you so much before.

 

[ditapark]

Here is the actual photo:

 

[BigH]

Sorry to say, typical Indonesian/Asian reporting: mass to the nearest gram and strength to the nearest 0.001 MPa (but likely nearest 0.01 MPa); have seen this a lot while working there. Along with using K instead of k for kilo; p instead of P in MPa . . .
while off tangent - are you sure that your batch plant / mix standard deviation is known? Normally, with new mix designs I sure wouldn't use 2 MPa as the standard deviation for the initial mix design until I had a history of the mix that you have designed. I have also seen, while working there, that the lad/lass making the cylinders are very variable from one person to the next and even with himself/herself - this affects the standard deviation of the mix.

Sika does have good people in Indonesia and SE Asia - as suggested by MotorCity, I would check with them. Why are you using such a high doseage - 2% which is the maximum that the product data sheet recommends. I know what they say about "rapid hardening" but it is not a hardener as, say, one would use in shotcrete. Did you stir the drums before you used them? We had a problem on two or three placements where we used something similar one time in Indonesia and the concrete did not set up . . . you might find that you had used a much more concentrated fluid than the 2% you thought due to separation of the material in storage.

As for removing the forms and finding cavities - didn't you vibrate? or are you using this as a "self compacting concrete"? Just wondering. Did you see loss of fines through form joints?