Cracks In Reinforced

CONCRETE  Foundations


Nowadays some principal properties like high-bond strength with high resistance to water penetration are missing during the production of concrete material. These desirable qualities play a crucial role in cracks found in concrete slab foundations of homeowners. 

What is Concrete?

Concrete is a heterogeneous material that consists of aggregates and cement pastes bonded together at the interface. It is inherently weak in tension due to the limited bonding strength and various preexisting microcracks and flaws that form during the hardening of the matrix. 

Since concrete is a mixture of broken stone or gravel, sand, cement, and water. It is not uncommon to see water leaving slabs of concrete in a large vacuum between the aggregate particles, especially in plastic states. The plastic shrinkage is one of the reasons behind cracks in the concrete foundation, in the long run, the emptiness makes the bonded material weaker and even weaker with time.

Fracture Process

The tension zone usually forms near the crack tip and undergoes a fracture process that includes things like microcracking, crack deflection, crack branching, crack coalescence. The weak interface between the aggregates and the cement paste constitutes the fracture or region of strain softening. Microcracks are tiny linear cracks that form in concrete, are generally not visible, and typically come with major and minor axes of the length of 400 and 100μm. It is advisable for a property owner, at some point, to have a basic understanding of these types of cracks, the causes, how to easily identify the nature of the problems, and what to do to prevent further damage to a building.

Multiple Crack Problems

A quick fix of what appears to be a mere crack oftentimes leads to a much larger problem. Matters go from bad to worse simply due to a lack of a proper understanding of the problem coupled with an ineffective method used to solve it. A study conducted by Griffith suggested crack propagation is inevitable due to an increasing tension load. No matter how small cracks are, the active one would create a future crack path due to the increase of load to which the house weight is subjected.

Every homeowner experiencing microcracks in their foundation stands the chance of witnessing crack propagation, crack arrest, and closure. The combination of these motions leads to increased possibilities of multiple crack paths forming causing irreversible damage to the structure of a building.  

Study shows that, when a beam of slab deflects, a partition wall becomes incapacitated thus causing the partition wall to fail. This happens because there is no slippage between the reinforcement and the surrounding concrete. The following factors are to be considered whenever such deflection is noticed:

✓  Immediate deflection due to snow or rain loads

✓  Permeation or penetration of water through the naturally occurring pores (tiny holes that form during the curing process) that induce damage to the foundation

✓  Pipe leaks from water or sewer lines, this factor usually goes for a long time unnoticed and may even pose greater damage to the property.

✓  Poor drainage channeling close to the foundation

✓  Larger temperature fluctuations that span between lowest and highest conditions during winter and summer also result in general concrete attrition (damage).

✓  Surface wear caused by physical abrasion or erosion

The Common Foundation Warning Signs

It pays to be observant! Especially when you live in this part of the world, with extreme weather conditions where a tiny problem may covertly develop into a larger problem if it goes unnoticed. Walking around your home regularly can help you quickly spot any obvious sign of stress or fracture in the foundation. 

Uneven floors

Windows or doors not closing as the weather changes

✓ Distorted gaps at the doors and windows

✓  Horizontal cracks in the siding

✓  Floors creaking or squeaking

✓  Floors creaking or squeaking

Sinking foundation

Waterlogged sections in the basement, stagnant water, or a wet musty smell in the basement

Altered or tilted chimney position.