Title:
In Situ strength Evaluation of Concrete
The Break-off Method
Author(s):
Randulf Johansen
Publication:
Concrete International
Volume:
1
Issue:
9
Appears on pages(s):
45-51
Keywords:
flexural strength; fresh concretes; hard-ened
concretes; inserts; tests; vacuum-treated con-crete.
DOI:
Date:
9/1/1979
Abstract:
The paper reviews results and experiences derived from the use of a new in-place testing method, with special reference to its application to an airfield pavement made of vacuum concrete. The testing method directly determines the flexural strength of the concrete in an annular cross section parallel to the concrete surface and at a definite distance from the surface. The sections to be tested are established by the aid of tubular inserts in fresh concrete or by drilling in hardened concrete. The results and experiences from practical application show that the method is fast and uncomplicated, and very sensitive to curing conditions. The paper also deals with the deficiencies of the prevailing control system, and with the technical and economical advantages achieved by putting more emphasis on the performance aspect. [Author]