Title:
Fatigue Strength and Endurance Limit of Lightweight Concrete
Author(s):
V. Ramakrishnan, T. W. Bremnerand V. M. Malhotra
Publication:
Symposium Paper
Volume:
136
Issue:
Appears on pages(s):
397-420
Keywords:
aggregates; compressive strength; fatigue (materials); flexural strength; lightweight concretes; shales; stresses; Structural Research
DOI:
10.14359/4130
Date:
1/1/1993
Abstract:
Presents results of an experimental investigation to determine the flexural fatigue strength of lightweight concretes made with expanded shale aggregates. Six mixtures were investigated. A total of 120 prisms (20 prisms measuring 76 x 102 x 406 mm for each mixture) were tested in flexural loading of 20 cycles per sec, Hz. The prisms that survived 2 million cycles of fatigue loading were tested in static flexure to determine their residual strength (modulus of rupture). The static flexural strength (modulus of rupture) ranged from 3.04 to 4.91 MPa. The fatigue strength varied from 2.2 to 3.0 MPa. The endurance limit (ratio of the fatigue strength to modulus of rupture) ranged from 0.55 to 0.72. The wet specimens tested at earlier ages had higher strength values (both fatigue strength and modulus of rupture), whereas the endurance limit was higher for dry specimens tested at later ages. There was an increase in the residual static flexural strength for the prisms previously subjected to 2 million cycles of fatigue stress.