Architecture Practice Exam

What minimum percentage of elongation is acceptable for grades 80 to 100?

1. 5%

2. 10%

3. 15%

4. 20%

The correct answer is: 20%

For grades 80 to 100, the minimum percentage of elongation acceptable is indeed 20%. This specification is crucial because elongation is a measure of a material's ability to deform plastically before breaking. It reflects the ductility and toughness of the material, which are critical properties for structural integrity and safety. A minimum elongation of 20% indicates that these materials can undergo significant deformation without failure, making them suitable for various applications where flexibility and resilience are required. Higher grades of materials are often subjected to more stringent performance criteria, which is why the elongation percentage is established to ensure that even at these higher strengths, the materials retain a reasonable degree of ductility. This becomes especially important in architecture and engineering, where unforeseen stresses may necessitate that materials can absorb energy without immediately fracturing. Understanding elongation percentages is vital for architects and engineers to select appropriate materials based on the specific demands of a project.