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Air, sunlight and moisture are the major causes of surface deterioration. Unprotected surfaces oxidate and allow the aggregate to be washed away. |
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Unprotected pavements lose flexibility; aggregate ravels from the surface and the pavement becomes rough. The surface becomes brittle and develops cracks. |
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Water penetrates the cracks and damage progresses. hydraulic pressure (expansion and contraction) enlarges the cracks. Damage occurs faster under heavy traffic and/or during freeze-thaw cycles. |
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Cracks allow water to penetrate to the sub-surface and rupture the pavement; causing small cracks to enlarge until the pavement actually separates, creating a pothole. |
