Double-leg reinforced concrete columns of one-storey frame buildings for seismic countries
Characteristics, a technique of prototypes and results of pilot studies of the bearing ability and a deformation of knots of reinforced concrete double-leg columns of one-storeyed frame industrial buildings are provided in article at action of low-cyclic sign-variable loadings of type of seismic. Knots were tested sign-variable cycles quantity not less than 30, at coefficient of asymmetry of a cycle, ρs =-1. The size of loading of a cycle was accepted by equal settlement seismic. Values of the skilled ultimate loads experienced knots, both single unilateral, and low-cyclic sign-variable by loadings exceeded values of settlement seismic loads of 50-87%. At the same time, decrease in the bearing ability of the knots tested by low-cyclic sign-variable loading of average and high levels in comparison with the bearing ability of the reference samples tested by single loading reached 20%. Materials with recommendations about tests of knots were used when developing a standard series of columns for application in seismic countries to 9 points.