In reinforced concrete walls, at what angle is temperature reinforcement used relative to the main steel?

• A. Right angles
• B. 45 degrees
• C. 30 degrees
• D. Parallel

Answer: (A)

Temperature reinforcement is used to control cracking from concrete shrinkage and temperature changes, and it is placed perpendicular to the main reinforcement. This right-angle orientation lets the restraint from temperature movements act across the panel in two directions, helping cracks form more uniformly and stay narrow. If the bars were parallel to the main steel or at a diagonal, the reinforcement wouldn’t effectively relieve stresses in both directions, so cracks could align with the main reinforcement or propagate more easily. Placing the temperature bars at a right angle to the main steel provides crosswise reinforcement that stabilizes the wall against temperature-induced cracking.