EK552
Strength and stiffness does not appear to be sensitive to the spacing of the ducts.
Strength and stiffness does not appear to be sensitive to the spacing of the ducts.
Plastic ducts do not provide confinement to the connector and grout, and appear to have a negative effect on the frictional resistance of the connection.
Polypropylene and polyethylene ducts did not confine the grout after theformation of widespread splitting cracks in the concrete.