Title: Tensile Strength of Concrete
Author(s): Jerome M. Raphael
Publication: Journal Proceedings
Appears on pages(s): 158-165
Keywords: compressive strength; concrete dams; dynamic loads; earthquake resistant structures; flexural tests; mass concrete; measurement; splitting tensile strength; static loads; structural analysis; tensile strength; tension tests.
A limiting factor in the safety of mass concrete structures, such as concrete arch dams under seismic loadings, is the tensile strength of the concrete. Tensile strength can be tested three ways: direct tension, splitting tension, and flexural tests. Results of these tests differ, and results of tests made on cores taken in the field differ from results made on laboratory specimens. Some 12,000 individual test results were examined to find reason for these discrepancies. Low tensile strength of cores from dams was found to be caused by drying shrinkage and surface cracking. Some tests were discarded because of flaws in testing technique. A theoretical relationship was found between tensile strength and modulus of rupture. Values are recommended for true and apparent tensile strength for a wide range of compressive strengths under static and seismic loadings.