Which of the following is true with respect to non-structural cracks?

Explanation:

Non-structural cracks are those that:

• Do not affect the stability or safety of a structure.

• Are mostly superficial and surface-based.

• Commonly occur due to:

  • Thermal expansion and contraction of materials.

  • Moisture variations (swelling and shrinkage).

  • Temperature changes causing expansion and contraction.

  • Drying shrinkage in concrete or plaster.

 Additional Information

Non-structural cracks, although not directly affecting the load-bearing capacity of a structure, can still lead to various issues over time. These cracks typically appear in non-load-bearing components, such as walls, floors, or ceilings, due to factors like:

1. Shrinkage: As concrete or plaster dries, it shrinks, leading to cracks. While these are not immediately structural threats, if moisture enters these cracks, it can accelerate the deterioration of materials, especially in reinforced concrete structures.

2. Temperature Variations: Temperature fluctuations cause materials like concrete, bricks, or plaster to expand and contract, leading to cracking. This might seem like a minor issue at first, but over time, repetitive movement can weaken the material, potentially creating pathways for moisture or salts that can cause further damage.

3. Moisture Changes: Moisture absorption and drying cycles can result in expansion and contraction, especially in materials like brick or plaster. This can cause cracks in the surface, which can allow water to penetrate, leading to corrosion of the embedded reinforcement, and eventually compromising structural elements.

4. Settlement: Minor settlement of the building or uneven foundation load distribution can lead to non-structural cracks. Although not immediately affecting the load-bearing elements, if the settlement continues or is uneven, it can lead to further cracks and potential foundation issues.