Which material would you use as initial backfill for asbestos cement pipe?

Which material would you use as initial backfill for asbestos cement pipe?

• A. Sand
• B. Gravel
• C. Clay
• D. Concrete

Answer: (A)

The main idea is that the first backfill around asbestos cement pipe must cushion the pipe and distribute loads evenly. A fine, clean layer of sand placed directly around the pipe provides that protective cushion. Sand fills gaps, compacts smoothly, and creates a uniform support so the brittle ACP isn’t subjected to sharp rocks or uneven pressure as the trench is filled. Gravel, being coarse, can create point loads and abrasive contact that risks cracking the pipe. Clay can trap moisture and swell, causing uneven support and settlement. Concrete is rigid and won’t accommodate movement, which can transfer stress into the pipe and cause damage.

The main idea is that the first backfill around asbestos cement pipe must cushion the pipe and distribute loads evenly. A fine, clean layer of sand placed directly around the pipe provides that protective cushion. Sand fills gaps, compacts smoothly, and creates a uniform support so the brittle ACP isn’t subjected to sharp rocks or uneven pressure as the trench is filled.

Gravel, being coarse, can create point loads and abrasive contact that risks cracking the pipe. Clay can trap moisture and swell, causing uneven support and settlement. Concrete is rigid and won’t accommodate movement, which can transfer stress into the pipe and cause damage.