CSLB Class B General Contractor's License Practice Exam

What term describes a crack in concrete that is due to failure in the base rather than the concrete itself?

1. Shrinkage crack

2. Structural crack

3. Settlement crack

4. Hairline crack

The correct answer is: Structural crack

The term that accurately describes a crack in concrete resulting from failure in the base rather than from issues within the concrete itself is "structural crack." Structural cracks typically indicate a deeper problem related to the foundation or the substrate upon which the concrete is placed. These cracks often arise from insufficient support, excessive movement, or inadequate engineering of the base, suggesting that the integrity of the overall structure may be compromised. For instance, if a foundation settles unevenly due to soil erosion or inappropriate compaction, the stress placed on the concrete can lead to structural cracking. This is distinct from other types of cracks, such as shrinkage cracks, which occur due to the natural drying and curing process of the concrete, often without any underlying base failure. Settlement cracks, although related to movement and shifting, specifically describe cracks resulting from the settling of the ground beneath the concrete rather than a direct failure of the concrete's structural integrity. Hairline cracks refer to very thin cracks that are often superficial and may not signify serious issues, typically arising from minor surface tension or drying. Understanding these distinctions is crucial for anyone involved in construction or concrete work, as it helps in identifying the root causes of cracking and determining appropriate remedial measures.