1. Cracks in horizontal surface , such as roof - Seal by brushing in cement or low viscosity polymer.
2.Blowholes in form surfaces - Fill with polymer modified fine mortar .
3. Voids in concrete - Cut loose things out and recast .
4. Cracks in thick sections occurring as concrete cools - Seal cracks.
5.Erosion of vertical surface , streaky pattern - Rub with polymer modified fine mortar.
6.Lack of cover to reinforcement - Apply protective coating with polymer modified cement sand mortar .