What is the accepted surface deviation for a Portland cement base course when using a ten-foot straight edge?

Answer: B — 3/4 inch

The accepted surface deviation for a Portland cement base course when using a ten-foot straight edge is indeed 3/4 inch. This standard is established to ensure the proper smoothness of the base course, which is crucial for the subsequent layers of pavement or other finishes to perform effectively. A tighter tolerance, such as 3/4 inch, helps to maintain the integrity and quality of the road by reducing the likelihood of defects that could lead to premature pavement failure or uneven wear over time. This specific tolerance reflects the balance between constructability and performance, allowing for practical construction while ensuring the base course remains an effective substrate for the final road surface. Proper adherence to this standard minimizes potential issues such as water pooling or compromised structural support, which can arise from excessive deviations.