I am making 9 concrete casts from a fiberglass mold I made from a 60 pound concrete pier cap. I understand that aggregate increases the strength of cured concrete, but these pier caps are only ornamental. Can I use just sand portland cement, instead of bagged concrete mix? If so, what should the ratio of sand to portland cement be? Any other suggestions or advice would be welcomed. ~ Thank you
Erm... sand + cement = mortar. Concrete includes rocks/pebbles (reckoning on the use). purchase some waiting blend concrete from a DIY save. end of subject. 40mm deep? Will you throw down some hardcore first? appears like this would be a activity for some paving slabs which *can* be laid with little bit of mortar.
yes you can use sand and cement only the ratio is 3 sand to 1 cement Although it is ornamental, I would still purchase a bag of pea pebble for 2 bucks and mix that into it. gently tap the sides of the cast to bring the juice to the sides to fill in any possible air gaps when you level the top, vibrate the board a little to also bring the juice up and eliminate air
