Hi folks, I'm going to be making a concrete worktop. I'm happy I've researched enough on the technique side but can't find much about the mix. I've had a chat with the technical guy at blue circle who was extremely helpful and suggested a 1-2-3 mix cement-sand-aggregate and suggested fine aggregate, around 1cm, and plasticiser, then vibrating the cr@p out of it. I shall do this with a hammer drill, a rounded-off bit and a steel plate from underneath the mold. I'm also going to be using steel reinforcing mesh and some rebar in the thin bits like around the sink.
One thing I'm not sure on - should I be using sharp or builder's sand? I've heard builder's sand may be slightly impure (may contain clay?) and thus the finished piece might not be as strong. However I've also read somewhere that cement using builders sand may 'flow' better, avoiding voids, and may help eliminate cracking. Any thoughts?
I did even wonder if a 1-1-1-3 mix might be worth trying -
1 part cement
1 part builders sand (or even plasterers sand maybe?)
1 part sharp sand
3 parts 10mm aggregate
I was thinking this might give a compromise between flowing and avoiding voids, and final part strength?
One thing I'm not sure on - should I be using sharp or builder's sand? I've heard builder's sand may be slightly impure (may contain clay?) and thus the finished piece might not be as strong. However I've also read somewhere that cement using builders sand may 'flow' better, avoiding voids, and may help eliminate cracking. Any thoughts?
I did even wonder if a 1-1-1-3 mix might be worth trying -
1 part cement
1 part builders sand (or even plasterers sand maybe?)
1 part sharp sand
3 parts 10mm aggregate
I was thinking this might give a compromise between flowing and avoiding voids, and final part strength?
