Title: Concentrated Loads on Hollow Concrete Masonry

Author(s): A. W. PageE and N. G. Shrive

Publication: Structural Journal

Volume: 87

Issue: 4

Appears on pages(s): 436-444

Keywords: concrete blocks; eccentric loads; failure; loads (forces); masonry; structural design; tests; walls; Design

DOI: 10.14359/3077

Date: 7/1/1990

Abstract:
Masonry design codes typically allow enhancement of masonry strength beneath a concentrated load due to the strengthening effect of the more lightly stressed surrounding material. This has been verified for solid masonry, but its applicability to face-shell bedded hollow masonry is open to question since failure occurs by splitting of the webs, rather than by vertical cracking. This study investigated the behavior of face-shell bedded hollow concrete masonry subjected to in-plane concentrated loads. A total of 49 wallettes, some plain and others with one and two-course bond beams, were constructed and subjected to either concentric of eccentric concentrated loads through various-sized loading plates. All wallettes failed consistently by local web-splitting, in a manner similar to hollow masonry subjected to uniaxial compression. The testing program is described together with detailed discussion of mechanisms of failure, dispersion of load through bond beams, influence of bond-beam grout strength, and potential strength enhancement. General implications for the design of hollow masonry subjected to concentrated loads are also discussed, and it is shown that strength enhancement occurs on the basis of loaded length rather than loaded area.