A laboratory and on-site test method for air permeability of concrete
Title: A laboratory and on-site test method for air permeability of concrete
Author(s): P. Paulini
Paper category : conference
Book title: 2nd International Symposium on Service Life Design for Infrastructures
Editor(s): K. van Breugel, Guang Ye, Yong Yuan
Publisher: RILEM Publications SARL
Publication year: 2010
Pages: 995 - 1002
Total Pages: 8
Nb references: 16
Abstract: The accuracy of permeability measurements in concrete depends crucially on a precise determination of the flow volume. By measuring the pressure drop in a vessel and calculating the air flow volume from these data the accuracy of test results is increased substantially. A pressure step technique is being used under steady state flow conditions and test data are analysed according to a new transport law. Two material parameters are used to describe the air flow in concrete. Based on laboratory permeability data the w/c ratio of the concrete mixture and the pore structure can be estimated fairly accurately.
On-site permeability tests are usually based on vacuum methods with non steady state flow conditions. The proposed Packer test uses a bore hole to fix a gasket with an injection packer on the member surface. Air pressures of up to 10 bars are applied under steady state conditions. The flow field is radially symmetrical over a wide range and a pressure gradient can be defined to analyse flow data. Practically all in-situ permeability tests are influenced by concrete humidity. Permeability data of on-site tests are scattered over a wider range compared to laboratory methods, but they are still a reliable indication of concrete quality.
Online publication: 2011-04-20
Publication type : full_text
Public price (Euros): 0.00