Virtual Labs

Behavior of steel rebar (reinforcement bars) under uniaxial tension

1. Which of the following is the correct expression for the ultimate strength?

a: 𝑈𝑙𝑡𝑖𝑚𝑎𝑡𝑒 𝐿𝑜𝑎𝑑 / 𝐼𝑛𝑖𝑡𝑖𝑎𝑙 𝑐𝑟𝑜𝑠𝑠 𝑠𝑒𝑐𝑡𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎 b: 𝑈𝑙𝑡𝑖𝑚𝑎𝑡𝑒 𝐿𝑜𝑎𝑑 / 𝐸𝑓𝑓𝑒𝑐𝑡𝑖𝑣𝑒 𝑐𝑟𝑜𝑠𝑠 𝑠𝑒𝑐𝑡𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎 c: 𝑈𝑙𝑡𝑖𝑚𝑎𝑡𝑒 𝑠𝑡𝑟𝑒𝑠𝑠 / 𝐼𝑛𝑖𝑡𝑖𝑎𝑙 𝑐𝑟𝑜𝑠𝑠 𝑠𝑒𝑐𝑡𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎 d: 𝑈𝑙𝑡𝑖𝑚𝑎𝑡𝑒 𝑠𝑡𝑟𝑒𝑠𝑠 / 𝐸𝑓𝑓𝑒𝑐𝑡𝑖𝑣𝑒 𝑐𝑟𝑜𝑠𝑠 𝑠𝑒𝑐𝑡𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎

2. Which of the following is the correct expression for the percentage elongation after fracture? ( Lu- final gauge length (after fracture) , Lo- initial gauge length , LT- final total length , Lt- initial total length of the rebar

a: (𝐿𝑢−𝐿𝑜 / 𝐿𝑜)×100 b: (𝐿𝑢−𝐿𝑜 / 𝐿𝑢)×100 c: (LT−𝐿𝑡 / 𝐿𝑡)×100 d: (LT−𝐿𝑡 / 𝐿T)×100

3. Which of the following property can’t be determined by a tensile test?

a: Yield strain b: Tensile strength c: Compressive strength d: Limit of proportionality

4. During a tensile test on a ductile material _____

a: Nominal stress at fracture is higher than the ultimate stress b: True stress at fracture is higher than the ultimate stress c: True stress at fracture is same as the ultimate stress d: None of the above

5. What will be the minimum diameter of a steel wire, which is used to raise a load of 4000N if the stress in the rod is not to exceed 95 MN/m2 ?

a: 6 mm b: 6.4 mm c: 7.3 mm d: 7.4 mm