ABSTRACT
Vacuum is created inside the 2-chamber vacuum cell, which is sealed onto the concrete surface by means of a pair of soft rings, creating two separate concentric chambers.
At a time between 35 and 60 sec Valve 2 is closed and the pneumatic system of the inner chamber is isolated from the pump. The air in the pores of the material flows through the cover concrete into the inner chamber, raising its pressure Pi. The rate of
1 INTRODUCTION
The so called “Torrent Method” measures the coefficient of permeability to air of the “covercrete”, in a completely non-destructive manner. Therefore it aims directly at specifying and controlling the “covercrete” quality of the end product: the finished structure.
