AbdolVahid Nemat - Master s Student of Kurdistan University
Emad Sheikhahmadi - Master s Student of Kurdistan University,

Concrete is one of the most widely used building materials whose Raw materials are inexpensive and available. Lightweight concrete is made using lightweight aggregates instead of natural aggregates (sand). The benefits of lightweight concrete include reduce concrete weight, reduce costs, strength against fire and reduce earthquake force. One of the most important weaknesses of lightweight concrete is its very low tensile strength which often leads to cracks in it. Self-healing is one of the newest methods of repair cracks in concrete. This method uses bacterial strains to repair the cracks. So that the bacteria become active after cracking in the concrete and entering the water into the crack and begin to produce sediments of calcium carbonate. These sediments fill small cracks inside the concrete. The benefits of self-healing method include non-interference and human error, Increased durability of concrete, and reduced post-construction maintenance costs. This article reviews and compares the bacterial activity in self-healing lightweight concrete types.

Lightweight concrete, Bacterial strains, Self-healing, Bacteria, Cracking, Calcium carbonate