Anchorage of reinforcement

The determination of anchorage and laps can be controlled by design rules. The anchorage development length is defined by the parameter “LB_D”, the engineer can modify the constraints file and influence on its calculation.

In the default constraint file, the anchorage length in defined according the Eurocode EN 1992-1-1:2004 as follows:

//$ --------------------------------------------------------------------
//$ 8.4 Anchorage of longitudinal reinforcement
//$ --------------------------------------------------------------------

//$ 8.4.2 Ultimate bond stress
f_bd = 2.25*eta_1*eta_2*f_ctd

//$ 8.4.2. Bond conditions
eta_1 = 0.7 ; isBondGood : eta_1 = 1.0
eta_2 = 1.0 ; d_asl > 0.032 : eta_2 = (0.132-d_asl)*10

//$ 8.4.4 Design anchorage length
lb_d = alpha_1*alpha_2*alpha_3*alpha_4*alpha_5 * lb_rqd * asl_util

//$ 8.4.4 (1) Minimum anchorage length
reinforcementInTension     : lb_d >= MAX(0.3*alpha_1*alpha_4*lb_rqd,10*d_asl)
reinforcementInCompression : lb_d >= MAX(0.6*lb_rqd,10*d_asl)

//$ 8.4.4 (2) alternative anchorage length
lb_eq = 0.7 * lb_rqd * asl_util

//$ Coefficients of Table 8.2
alpha_1 = 1.0 //$ factor considering shape of bars
alpha_2 = 1.0 //$ factor considering concrete minimum cover
alpha_3 = 1.0 //$ effect of confinement by not welded transverse reinforcement
alpha_4 = 1.0 //$ effect of confinement by welded transverse reinforcement
alpha_5 = 1.0 //$ effect of transverse pressure

The anchorage length is considered for the visualization of the reinforcement as an offset on the inserted reinforcement range measured since the beginning/end of the bars. Below the anchorage length is highlighted green next to the boundary of the reinforcement distribution diagram.