Sika Hibond is a structural bonding agent between old and new concrete.It has a long potlife and open time allows sufficient time for placement of new concrete. Works well on moist surfaces also. Sika Hibond is a structural bonding agent applied between old and new concrete surfaces during casting of roof slabs, retaining walls, water tanks, coloums, extension of balconies, etc.Once the 2 components of the materials are mixed, the material must be used within its potlife of approx 3hrs