Safety Inspection of In-Service Bridges Practice Test

Growth features are built into wood because they arise from how the tree grew. Knots form where a branch was, interrupting the continuous fiber flow and creating weak spots where stress concentrates under load. Splits and checks are cracks that develop as wood dries or shrinks along its growth rings, breaking fiber continuity and reducing strength. Reaction wood appears when a tree leans or grows under unusual conditions; its fibers are oriented differently and its density changes, which can weaken the wood in the direction of loading. Because these issues originate in the tree’s growth and affect the structural integrity of the wood, they are classified as growth features. Surface flaws or cosmetic color variations don’t capture these internal, growth-related weaknesses.