Which of the following describes a key characteristic of CLSM compared with traditional concrete?

• A. It has a compressive strength lower than traditional concrete
• B. It has higher compressive strength than traditional concrete
• C. It cures without moisture
• D. It is not suitable for backfilling applications

Answer: (A)

The key idea is that CLSM is a low-strength fill material designed for backfilling, not for carrying structural loads. It’s engineered to be just strong enough to support itself and utilities temporarily, and to remain easy to excavate if future access is needed. That’s why its compressive strength is intentionally lower than traditional concrete, which is built to carry significant loads and provide structural support over time.

Curing with moisture is the normal practice for concrete, including CLSM, so curing without moisture isn’t a defining feature of CLSM. And CLSM is specifically intended for backfilling, not for exclusion from such use, so stating it isn’t suitable for backfilling isn’t accurate. The statement about higher compressive strength would contradict the very purpose of CLSM.