I'm trying to make some concrete dumbbells at home, but I messed up. I thought I bought concrete, but it was just gravel. Now I've got a bag of gravel and cement, and I realize I need sand for proper concrete. Is it possible to create concrete using just crushed gravel, regular gravel, and cement? Will that be strong enough, or am I setting myself up for a failure?
3 Answers
Concrete is basically cement mixed with an aggregate, which can be gravel or sand. Without sand, your mix will be too weak. You can technically use pure cement, but it's not advisable. If you've got time, maybe test a small batch and see how it holds up. That way you can figure out if you can make it work or if you'd just rather return the gravel for a proper concrete mix.
You’d definitely want to add sand if you're mixing concrete yourself. Most common ratios are 1 part cement, 2 parts sand, and 4 parts gravel. Without sand, you might end up with a weak mix, especially if the dumbbells are going to bear weight.
Got it! I’ll grab some sand before I start mixing. Thanks for the tip!
If your molds are going to hold the shape, you might get away with just gravel and cement. But if you plan to actually use them and want them to stay intact, definitely buy some sand. You need a proper mix for durability!
Yeah, I’m thinking durability is key here. I’ll look for sand!
That sounds like a good idea! I’ll try a test piece first.