Âm thanh chia sẻ

Concrete and Steel - A Perfect Team Concrete is a very hard material. It is strong when you push on it. But concrete has a weakness. It is not strong when you pull on it. Imagine bending a piece of chalk. It breaks easily. Steel is different. Steel is very strong when you pull on it. So, engineers put steel bars inside concrete. These bars are called rebar. The rebar gives the concrete strength against pulling. They work together as a perfect team. CONVERSATION 2: Studying for a Test Two st