Structural Repair using Gunite
Gunite is the most effective process for structural repairing of large scale concrete works which have been damaged due to inferior workmanship, impact damage, ect. Gunite provides a quick fix concreting while providing a impervious layer. It is a mixture of cement and sand in the proportion of 1:3. A cement gun is used to distribute the mixture onto the concrete structure using a pressure of 2-3 kg/cm2. Prior to Gunite the concrete structure surface is to be cleaned and washed. The nozzle of the cement gun is kept at a distance between 75-85cm away from the treated surface. The velocity of the nozzle varies from 120-160 m/s, the reason for this high velocity is so that it compacts the material on placement.
It is noted that Gunite is different to Shotcrete. Gunite is concrete applied with a dry mix process whereby it is water free until the builder applies it. Whereas Shotcrete is a wet mix concrete where the concrete blend is already premixed with water prior to application