North Carolina Building Contractor License Practice Exam

Mechanical connections must allow the bars to develop what percentage of the yield strength in tension?

1. 100%

2. 110%

3. 125%

4. 150%

The correct answer is: 125%

The correct percentage of yield strength that mechanical connections must allow the bars to develop in tension is 125%. This requirement is grounded in ensuring that the connections are capable of sustaining the tension forces exerted on them under various loading conditions. In construction and engineering practice, particularly when dealing with reinforcement steel and other mechanical connections, a percentage higher than 100% indicates that the connection is designed to handle unexpected loads or strains. The 125% requirement can be attributed to industry safety standards, which call for a factor of safety to account for potential variations in material properties, construction techniques, and environmental influences that could affect performance or integrity. In this context, developing 125% of yield strength provides additional assurance that the components will work together reliably under load, minimizing the risk of failure and ensuring structural integrity. It emphasizes the importance of overdesigning components in critical structural applications to accommodate unforeseen challenges.