What waste factor is applied in the example problems?

What waste factor is applied in the example problems?

• A. 5%
• B. 10%
• C. 15%
• D. 20%

Answer: (B)

The idea being tested is how much waste is added to material quantities to cover losses during mixing, transporting, placing, and finishing of flatwork. In these example problems, a ten percent waste factor is used to ensure enough material is on hand without underestimating. This ten percent accounts for concrete that sticks to forms, spillage, handling losses, and adjustments during finishing. It strikes a practical balance: it reduces the risk of ordering short while not inflating quantities too much. A quick way to apply it is to multiply the calculated volume by 1.10. For example, if you estimate 50 cubic yards needed, ordering 55 cubic yards (50 × 1.10) covers the anticipated waste. Other options would either under or overestimate typical losses: 5% may be too low to guard against waste, while 15% or 20% would overestimate and raise costs unnecessarily.

The idea being tested is how much waste is added to material quantities to cover losses during mixing, transporting, placing, and finishing of flatwork. In these example problems, a ten percent waste factor is used to ensure enough material is on hand without underestimating.

This ten percent accounts for concrete that sticks to forms, spillage, handling losses, and adjustments during finishing. It strikes a practical balance: it reduces the risk of ordering short while not inflating quantities too much.

A quick way to apply it is to multiply the calculated volume by 1.10. For example, if you estimate 50 cubic yards needed, ordering 55 cubic yards (50 × 1.10) covers the anticipated waste.

Other options would either under or overestimate typical losses: 5% may be too low to guard against waste, while 15% or 20% would overestimate and raise costs unnecessarily.