A steel bar chair is a support used in construction to maintain the correct position of steel reinforcement bars in concrete. It ensures that the bars remain properly spaced and elevated within the formwork, allowing concrete to flow evenly around them, which is crucial for structural integrity.
A spacer is a small device placed between reinforcement bars or between the bars and formwork. Its purpose is to maintain the required distance or cover, ensuring that the bars are positioned correctly within the concrete and protected from corrosion.