Q. Define lap length of reinforcement?

In some structural codes, lap length of reinforcement is simplified to be a certain percentage (e.g. 25%) higher than anchorage length. This necessity is to cater for stress concentrations at the end of lap bars. A smaller load when compared with load to pull out an anchored bar in concrete triggers splitting of concrete along the bar since the effect of stress concentration. A higher value of lap length is adopted in design code to provide for this phenomenon.