Title:
The Camera Lucida Method for Measuring Air Voids in Hardened Concrete
Author(s):
George J. Verbeck
Publication:
Journal Proceedings
Volume:
43
Issue:
5
Appears on pages(s):
1025-1040
Keywords:
none
DOI:
10.14359/8772
Date:
5/1/1947
Abstract:
The camera Lucida method for the determination of the air content and the air void characteristics of hardened cement pastes, mortars, and concretes is described. Data are included to demonstrate the influence of experimental factors on the results obtained by the camera lucida method. A comparison is made of the void concentrations and averaae void areas of the air entrained bv different types of agents and under different mixing conditions. No factors significantly alterinq the void characteristics in concrete are revealed in the tests thus far made. The air contents of hardened concretes as determined by the camera lucida method com-pare satisfactorily with results obtained by other methods applied to the same concretes when in the plastic state.