Bought Robo sand from Robo silicon

[dream_home]

you can use m-sand or robo sand as it is. for concrete i maintained 1:2:3 ratio. for block work 1:5. Also there is no restriction of using 53 grade cement while using Robo/m-sand. I have used Mycem cement slag based for all my work. Except for pillars which i used Birla super. In 1 floor i have used Mycem for pillars also. The setting time is more in Mycem, otherwise it is very strong. Cost is also very less i am procuring directly from factory using contacts @275/bag, whereas birla super is around 340/bag at retail.

[basha_skj]

@Nikhilsuresh,
OPC cement is the product lime, as I am new to construction field, may I know , why we have to add further lime in RCC slab?

[nikhilsuresh]

Lime is a hydraulic sealant concrete has capillary pores and hence permeable..the goal here is to reduce the permeability..lime if you observe is an age old hydraulic sealant..you can used slag based cement too...GGBS cement that is.KRS was built with hydraulic lime..

[Manjunath711]

hi basha_skj,
Go with ratio 1:1.5:3, and from my view I think no need to add any chemical further

Manjunath.K.N.
Structural Designer

[zahid]

I agree with @Manjunath. We used the same ratio of Cement:Robo Sand:20 mm Gravel (1:1.5:3) for footings. The same ratio was suggested by ACC folks as well. We used ACC Concrete Plus cement, which is PPC cement. We did not add any other chemical / lime / etc. However, in case there is benefit from adding hydraulic lime, as @NikhilSuresh has mentioned, you could try that and let us know the results.

[Manjunath711]

Hi Zahid,
The cement used by you is PPC which is an low heat cement in comparison with OPC and thus release of heat energy at a lesser rate nad chances of shrikage cracks are lesser

Manjunath.K.N.
Structural Designer

[zahid]

@Manjunath - That's correct. That's the reason I opted for ACC Concrete Plus PPC cement for all concrete work - for footings and columns. I opted for M20 strength RMC for roof slabs. Did not go for site mixing. Overall, my mestri is satisfied with the results so far.

[Pallavi1]

Zahid,
What you have opted works economical only with RMC and not with regular site mix.
In general for RMC to be economical, Building plinth area to be more.

Manjunath.K.N.
Structural Designer

[baruc2003]

Hi all,
Thanks for throwing light on all my doubts and now the plinth work is complete. Luckily concrete has come out well and ratio used was cement 2: sand 5 : aggregate 6-7. Even the sump mould is done. I'll put up pics once the centering sheets are removed. I'm using KCP cement and it's good. I'm selectively using 53 grade for columns and beams.Ppc for plastering. I use ppc for Concrete sometimes. Pls advice me if something has to be changed.
Thanks,
Bharath

[iamveer]

you can use m-sand or robo sand as it is. for concrete i maintained 1:2:3 ratio. for block work 1:5. Also there is no restriction of using 53 grade cement while using Robo/m-sand. I have used Mycem cement slag based for all my work. Except for pillars which i used Birla super. In 1 floor i have used Mycem for pillars also. The setting time is more in Mycem, otherwise it is very strong. Cost is also very less i am procuring directly from factory using contacts @275/bag, whereas birla super is around 340/bag at retail.

Hi dream_home,

Can you call me at 9611222885 please, need to discuss few points on PSC based mycem cement, its setting time when used in columns, slabs, brick walls, plastering etc.

Raghuveer
Mob: +91-9611222885