Problems on Practical Construction of Durable Concrete with Controlled Permeability Formwork Liner

Controlled permeability formwork liner (CPFL) is used commonly on numerous major concrete structures for durability due to its functional compacting concrete surfaces. However, existent problems of CPFL according to series test in-situ and laboratory by author are claimed. Firstly, the effective expelling excess water and air from fresh concrete discounted obviously, and will no longer been reusing because of clogging rate of liner increased seriously after pouring with formwork two or three times continued. Secondly, concrete block surface cast subsequently is formed unsmooth due to wrinkles caused by CPFL deformation and hydroscopic properties changed and thirdly, the improvement for bottom surfaces are far less than both inclined and vertical surfaces because of weak expelling on horizontal formwork. Some efficacious methods and engineering measures are presented to solve above problems according to author's study.