Work Item
ASTM WK90073
New Test Method for Air-Permeability Coefficient of Hardened Concrete by the Double-Chamber Vacuum Cell Method
1. Scope
This test method covers the determination of the air-permeability coefficient of hardened concrete by the double-chamber vacuum cell technique. In particular, this non-destructive test method evaluates the penetrability of the near-surface concrete, which is vital for resistance to penetration of deleterious agents. The important effect of moisture is considered by using a standardized electronic moisture meter to estimate the near-surface moisture content. The method is applicable to laboratory testing of specimens or to in-place testing of concrete construction elements.
Keywords
air-permeability; in-place testing; moisture content; nondestructive testing; penetrability, durability
Rationale
Currently, the in-place test methods covered by Subcommittee C09.64 do not include tests of durability-related properties. Additionally, the test methods related to mass transport properties covered by Subcommittee C09.66 are not well suited for in-place testing. The proposed NDT method to measure the air-permeability coefficient by using a double-chamber vacuum cell device aims to fill both gaps. The proposed method has been studied extensively in many countries and its performance is documented in the book Concrete Permeability and Durability Performance – From Theory to Field Applications, authored by R. Torrent, R. Neves, and K. Imamoto, and published by CRC Press. The test method has been standardized in Switzerland, Japan, and Argentina.
An advantage of this method over electrical methods, which provide an indication of mass transport properties, is that the results are not affected by the ionic composition of the pore solution or by conductive admixtures, fibers, etc. The proposed method accounts for the in-place moisture content by an independent measurement of the near surface moisture content of the concrete using a standardized electronic moisture meter and applying a correction factor to the measured air-permeability coefficient. This test method will provide a tool for assessing the adequacy of mix design and concreting practices – chiefly curing- which are critical for producing durable concrete surfaces. Designers can specify air-permeability coefficient limits based on their durability designs, and owners can assure that the limits are not exceeded through on-site testing during construction.
The title and scope are in draft form and are under development within this ASTM Committee.
Work Item Status
Date Initiated: 03-25-2024
Technical Contact: ROBERTO TORRENT
Item: 000
Ballot:
Status: