STP778: Shear Capacity of Reinforced Concrete Masonry Beams

    Suter, GT
    Carleton University, Ottawa, Ontario

    Keller, H
    Carleton University, Ottawa, Ontario

    Pages: 29    Published: Jan 1982


    Abstract

    Extensive research is under way in many parts of the world to move masonry design from an allowable stress approach to a more consistent ultimate strength approach based on limit states criteria. At Carleton University over the past three years work towards limit states design has concentrated on concrete masonry flexural members such as lintel beams or slender shear walls. This paper deals with the ultimate strength and behavior of flexural members subjected to high shear forces. The experimental investigation, comprising over 70 concrete masonry beams, studied the effect of a number of key parameters on shear capacity. These parameters were the ratio of shear span to effective depth, joint spacing, type and slump of fill, effective depth, coursing of beams, and percentage of reinforcement. The results show that ultimate beam shear capacity of reinforced concrete masonry falls between the shear strengths of reinforced concrete and reinforced brick masonry. The results also show that the ratio of shear span to effective depth has the most pronounced effect on shear capacity and that, in general, composite behavior exists up to ultimate failure. No serviceability problem exists for deflections at working load levels.

    Keywords:

    masonry, shear strength, shear arm ratio, effective depth, percentage reinforcement, joint spacing-crack initiation, type of fill, slump of fill, two-course beams, relative shear strength, deflections, concrete blocks, control specimens, compressive strength, testing, mortar in lieu of grout, instrumentation


    Paper ID: STP30119S

    Committee/Subcommittee: C15.03

    DOI: 10.1520/STP30119S


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