TENSILE AND FLEXURAL STRENGTH OF CEMENT MORTAR SUBJECTED TO NONUNIFORM SELF-STRESS

In order to generate non-uniform self-stress that is different in area of working zone, the partial surface provided by controlling the coating area of mortar beams was exposed to drying conditions. The distribution of self-stress was experimentally determined by measuring the variation in strain when a part of the specimen was cut or notched. The beams were uniaxially or flexurally loaded, and the ultimate load was experimentally determined. The elastic strain due to self-stress was superposed on the strain due to the external load, then the stress distribution was determined from a simplified stress-strain curve in which tension softening was taken into consideration. The values of ultimate load which were calculated from the stress distribution showed good agreement with the observed ones.