Concrete @ your Fingertips

Blemishes defects and failures

Concrete is not a homogeneous material and will always exhibit some blemishes. These will affect the appearance of the concrete surface but will not generally affect the performance of the structure.

A defect, something that causes obvious serviceability or structural issues, can usually be rectified whereas a failure will generally be due to major design or construction error or to some extreme event, such as serious overloading.  

Acknowledgement: The Concrete Society