Mixture questions for high strength concrete
Mixture questions for high strength concrete
(OP)
I'm doing a competition for a construction materials course and need to make the strongest possible cylinder. The only guideline is the cement cannot exceed 450kg/m^3.
So far the assumptions I have made are that I should use the maximum cement allowed and I need the lowest possible water ration to complete the reaction which I think is around 0.25, along with the addition of a super plasticizer. Can anyone tell me if this is correct?
Also, for the aggregates, should I use slag, flyash, metakaolin, silica fume or just a fine aggregate and what ratios should be used.
It's worth noting that I have ~30 days until the competition but I do have access to accelerated curing methods.
Any help or suggestions would be greatly appreciated!
So far the assumptions I have made are that I should use the maximum cement allowed and I need the lowest possible water ration to complete the reaction which I think is around 0.25, along with the addition of a super plasticizer. Can anyone tell me if this is correct?
Also, for the aggregates, should I use slag, flyash, metakaolin, silica fume or just a fine aggregate and what ratios should be used.
It's worth noting that I have ~30 days until the competition but I do have access to accelerated curing methods.
Any help or suggestions would be greatly appreciated!





RE: Mixture questions for high strength concrete
I would use silica fume and make sure the aggregate is crushed and washed. Better start now with some trials.
http://www
Fibres not allowed I guess.
RE: Mixture questions for high strength concrete
Silica fume will increase your density - it might also increase your water demand due to it's increased surface area. The super plasctizer will allow you to use as little water as possible, thus increasing the strength.
I stand to be corrected.
RE: Mixture questions for high strength concrete
RE: Mixture questions for high strength concrete
The sand/cement mix gave higher strengths at 7 and 28 days and also broke in a more "organised" manner - it cracked along the edges of the cubes and did not form the hour glass shape like normal stone/sand/cement cubes normally do.
The damage or cracks on the sand/cement cubes are also less visible than the stone/sand/cement mix cubes. I initially questioned if they were actually crushed, but the lab guy insisted they were. I crushed them again in any case and got some decent figures for a 2nd time. I was amazed at the sand/cement mix's results.