Title:
Shrinkage Stresses in Concrete
Author(s):
Gerald Pickett
Publication:
Journal Proceedings
Volume:
42
Issue:
1
Appears on pages(s):
165-204
Keywords:
none
DOI:
10.14359/8708
Date:
1/1/1946
Abstract:
Theoretical expressions for deformations of concrete beams and slabs that occur during the course of drying and expressions for distribution of the accom-panying shrinkage stresses are derived in Part I. These expressions are derived on the assumption that the laws governing the development of shrinkage stresses in concrete during drying are analogous to those governing the development of thermal stresses in an ideal body during cooling. Three cases are considered: a) slab or beam drying from one face only; b) slab or beam drying from two opposite faces; and (c) prism drying from four faces. The applicability of the equations to concrete is considered in Part 2. It is shown that the course of shortening of prisms is in good agreement with the theoretical eauations and that from a test on one prism the shdrtening versus period of drying ot other prisms of the same material differing in size and number of sides exposed to drying can be predicted with fair accuracy if the differences in size are not too great. However, it is shown that the theory must be modified to take -into account in elastic deformation and to permit the supposed constants of the material to vary with moisture content and size of specimen if the theory is to be in agreement with all results on all types of specimen of a given concrete. Various tests are described which., when used inconjunction with the theory, provide a means tor studvina some of the more fundamental properties of concrete and for predicting the performance of concrete under some conditions in the field.