Analysis and behavioral characteristics of hollow-core plank diaphragms in masonry buildings
The behavioral characteristics of floor diaphragms constructed of hollow-core planks were investigated, and analytical models to predict the strength of the diaphragms were developed in this study. Seventeen full-scale diaphragms were tested under the Sequential Phased Displacement Load Program (SPD). The parameters tested included plank orientation, number of sides connected to the loading frame, addition of a 2-inch topping, plank thickness, number of seam fasteners, and effect of the testing frame stiffness;The behavioral characteristics identified were: the initial stiffness, the First Major Event (FME) load, the limit state load, and the failure modes. The comparison of the experimental results revealed that connecting the diaphragm on all four sides, and orienting the planks perpendicular to the loading direction or addition of the topping, resulted in the best diaphragm action;Expressions to predict the strength and stiffness of the diaphragms were developed based on the edge zone concept and an assumed stress distribution between the planks. Finite element analyses were performed to verify the assumed stress distribution. The predicted and the experimental results were compared. The analytical predictive equations showed a good agreement with the experimental results.