Concrete formwork for the lining material and concrete formwork and hitting method of concrete

摘要

PURPOSE:To discharge (deaerate and displace drainage) bubbles and excess water collected on the surface of placed concrete without causing clogging by constituting a lining material for a concrete frame mold of a water-permeable laminated sheet which is formed of both a filter layer made of high-density fabric and a water-permeable layer made of nonwoven fabric and has specified coefficient of water permeability. CONSTITUTION:A lining material for a concrete frame mold is constituted of a water-permeable laminated sheet which is formed of both a filter layer 2 made of high-density fabric having 50-200mum knot and a water-permeable layer 3 made of nonwoven fabric having 0.1-0.5g/cm2 apparent fiber density and has =1X10-4cm/sec and 1X10-2cm/sec coefficient of water permeability. When concrete is placed in such a way, the specified lining material is fitted to the inside of the frame mold. Bubbles and excess water which are generated on the surface layer part of concrete can be easily discharged through the lining material. Beautiful concrete free from a pinhole and a crater can be repeatedly produced.