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一、预应力钢筋的传递长度先张法预应力混凝土构件,在放松应力钢筋后,预应力钢筋靠与混凝土的粘结力和两者间的挤压作用,将力传递给混凝土,这个端部传力区段的长度称为传递长度L_c。在传递长度范围内,钢筋的应力变化可近似地按直线考虑,钢筋的实际预应力从构件端部的零值按直线规律增大,直至传递长度的末端达到有效预应力值σ_y(见图1)。因此,在计算构件端部的正截面和斜截面抗裂度
First, the pre-stressed steel transfer length of the pre-tensioned prestressed concrete components, after relaxing stress steel, prestressed steel and the concrete by the adhesion force and the compression between the two, the force is transmitted to the concrete, this end The length of the force transmission section is referred to as the transmission length L_c. In the transmission length range, the stress change of the steel bar can be approximately considered in a straight line. The actual prestress of the steel bar increases from the zero value at the end of the component in a linear manner until the end of the transmission length reaches the effective prestress value σ_y (see Figure 1). ). Therefore, the normal section and oblique section crack resistance at the end of the calculation member