Title:
Size Effect in Brazilian Split-Cylinder Tests: Measurements and Fracture Analysis
Author(s):
Zdenek P. Bazant, MohammadToshiaki Hasegawa, and Jacky Mazars
Publication:
Materials Journal
Volume:
88
Issue:
3
Appears on pages(s):
325-332
Keywords:
cylinders; failure properties; splitting tensile strength; size screening; tests; Materials Research
DOI:
10.14359/1987
Date:
5/1/1991
Abstract:
Size effect in split-cylinder (Brazilian) tensile tests is studied experimentally and analyzed theoretically. Tests of a very broad size range, 1:26, were conducted on cylindrical disks of a constant thickness made from concrete with aggregate of a maximum 5-mm size. The results confirm the existence of size effect and show that up to a certain critical diameter dt the curve of nominal strength versus diameter approximately agrees with the law proposed by Bazant for the size effect caused by energy release due to fracture growth. For larger sizes, there appears to be a deviation from the size-effect law, although large scatter of the test results does not permit a strong conclusion in this regard. The trend of the size effect curve is probably an approach to a horizontal asymptote with or without a reversal of slope of the size-effect curve. The reversal can be explained by a modification of the size-effect law in which the crack length at failure ceases to increase in proportion to the diameter and may remain constant for sizes larger than a certain characteristic size. The approach to a horizontal asymptote can be explained by a plastic slip on wedge-shaped regions below the platens.