SURFACE PREPARATION

• Concrete should be old enough, if it is newly placed concrete then it needs to be 28 days old and to have reached its design strength.
• Concrete should have attained a minimum compressive strength of 21 MPa, higher strength concrete is recommended for optimum performance of grout.
• All surfaces should be dry, clean, and free from standing water, grease, curing compounds, mold oils, all loosely adhered aggregates and cement particles, etc.
• Chip the concrete surface so aggregates are exposed to ensure all laitance and weak particles are removed. Alternatively use a spray on surface retarder when placing concrete. The exposed aggregate amplitude should not be greater than 10-15 mm.
• Chamfer the edges of the concrete 45 degrees to 50 mm. width to avoid sharp corners which helps to reduce the potential for cracking.
• Shade the foundation from direct sunlight for at least 24 hours before grouting and 48 hours after grouting.

MIXING

• Before mixing ensure all the components are cool, shaded and dry. If not preconditioned store all components below 25°C for 24 hours before using.
• The temperature of grout, baseplate and foundation are more important than the air temperature because they are directly related to the flow of grout.
• Add component A & B in a mixing vessel and mix under slow speed (400 rpm) for approximate 1 minute. Then add component C and continue mixing until a flowing uniform grout is achieved.
• Avoid excessive mixing which will result in reduction of working time and heat generation.

APPLICATION

• While grouting the base plates ensure there is sufficient pressure head to maintain movement of grout.
• Base plates with a flat base pour the grout from one side through the other across the short dimensions.
• Ensure entrapped air can escape when grouting closed areas.
• Where grout cannot flow and have smooth movement because of the length of pour pushing aids like steel chains, strips of plywood, etc. can be used.
• The base plate with anchor bolts, dowel, starter bar, etc. should be grouted first followed by the base plate.
• If grouting in multiple layers, it is necessary to sprinkle a small amount of 2.5 mm aggregate over the first layer before the grout reaches its setting time. Before placement of 2nd layer brush
• out loose aggregates from the 1st pour. Another method is to scrabble gently the top surface and make it rough when grout reaches near to its setting time.