how to place reinforcement ? 1. remember Bending moment Diagram , Sag and Hog which curves of upward and down ward while drawing moment Diagram. the sag or up ward curve shows positive moment while Hog shows negative moment 2. where is the maximum positive and maximum negative? positive moment is maximum at midspan while negative moment maximum at support. 3.where is lapping? for positive reinforcement at support while at mid span for negative reinforcement .