ABSTRACT
The stability of precast concrete buildings is provided in two ways. First the horizontal loads due to wind are transmitted to shear walls or moment resisting frames by the floor acting as a horizontal deep beam. Second, the horizontal reaction forces resulting from the floor at each floor level are transmitted to the foundation via columns or bracing elements. If the floor diaphragm is subjected to horizontal bending, the internal equilibrium is maintained by tension and compression chords. The floor diaphragm is subject to an ultimate horizontal uniformly distributed load of 4 kN/m run. The most important feature of the floor design for ensuring horizontal diaphragm action is the edge profile. There is no horizontal shear transfer mechanism between individual floor units, as with beam-and-block floors. If either of these conditions apply, the diaphragm forces must be transmitted by other means.
