Why Do Sidewalks Have Cracks?

Have you ever been walking down the street and started to wonder why do sidewalks have cracks? It’s a common question and can be interpreted in two slightly different ways, but both ways have very similar answers. To determine why do sidewalks have cracks, you have to distinguish between actual cracks and the pre-made lines, called contraction joints, that are created when laying sidewalks down.

Contraction Joints

If, when you ask why do sidewalks have cracks, you mean why are sidewalks made with lines already in them, the answer to this is simple. Contraction joints exist so that when the sidewalk inevitably cracks, it cracks inside the lines rather than on the action walking surface. Contraction joints are one of many types of concrete joint but are the most common in regard to sidewalks.

According to US Department of Transportation, concrete is the most popular paving material for sidewalks. Unfortunately, concrete shrinks as it dries and continues to get smaller as it ages, resulting in cracked sidewalks. In order to keep sidewalks in good shape, workers will cut contraction joints in the concrete slabs. This weakens that one section of the sidewalk so that, when the sidewalk goes to crack, it defaults to the weakest point in each slab, the contraction joint.

Natural Cracks

If your concrete doesn’t have contraction joints, your concrete will likely still crack very quickly. Again, concrete shrinks as it dries, and this movement can’t happen without joints in the paving material. All natural cracks are joints that the concrete creates for itself to accommodate the natural shifting of the material.

Another possible answer for why do sidewalks have cracks is because of nature. As the ground shifts, sinks, and moves due to the pressure and movement from the elements, sidewalks crack. You can’t avoid fissures because you cannot prevent your sidewalk from being impacted by nature.

Why Do Sidewalks Have Cracks | Absolute Pavement Services

Cracks and lines in sidewalks serve the exact same purpose in the grand scheme. Both act as joints to allow the concrete to move as it needs to in response to other pressures. However, the lines  preserve the appearance of your sidewalk and prevent unseemly cracks in the middle of the slabs. If you need a sidewalk put in or are simply looking for answers to more questions like ‘why do sidewalks have cracks,’ visit the Absolute Pavement Services website and learn more today!