Title:
BEARING STRENGTH OF CONFINED CONCRETE
Author(s):
Rodolfo Bonetti, Carin L. Roberts Wollmann, and Juan T. Santos
Publication:
Structural Journal
Volume:
111
Issue:
6
Appears on pages(s):
1317-1328
Keywords:
bearing strength; concrete blocks; confined concrete
DOI:
10.14359/51687163
Date:
11/1/2014
Abstract:
An investigation has been performed on the influence of confining reinforcement on the bearing strength of concrete blocks. Square prisms 8 in. (203 mm) wide and 16 in. (406 mm) tall were reinforced with ties, spirals, and a combination of spirals and ties. The volumetric reinforcing ratio ?v varied from 0 to about 10%. Concrete strengths ranged between 2700 and 6230 psi (18.6 and 42.9 MPa). Specimens were loaded with steel plates and the ratio of supporting area to bearing area was kept constant at 4. Strain measurements were made of the reinforcement to confirm steel yielding and at the surface of the concrete blocks to record first cracking load. Analysis of the test data shows that the first cracking load is independent of the reinforcing ratio and is accurately predicted by an equation based on the Mohr failure criterion. Data also indicate
that ultimate strength increases linearly with the confining pressure up to a volumetric reinforcement ratio of 10%. Test results from previous investigations were also compared to proposed equations.