Q. A post that is part of my stockade fence is loose. When the wind blows the fence rocks back and forth and makes the post weaker. Can I fix this myself? I am a senior citizen and don't want to be ...

No, it's not a grunge band—it's a powdery binding agent that mixes with gravel, sand, and water to form the hardened slab we call concrete. It's made by heating limestone, iron, alumina, and silica to ...