Materials of Construction – Properties, Testing, and Standards Practice Test 2026 - Free Construction Material Practice Questions and Study Guide

Sharp-edged aggregates create mechanical interlock in the concrete, where the jagged faces grip neighboring grains and resist movement under load. This interlock distributes stresses more effectively and improves shear strength because the particles catch on one another rather than simply sliding past, leading to a stronger composite before the paste fails. Rounded aggregates, by contrast, roll and slide more easily, which boosts workability but reduces interlock and shear resistance. Irregular shapes can vary, but the defining feature for promoting interlock is the distinct sharp edges of angular aggregates, which provide the grip needed to restrain particle movement. Flaky aggregates tend to align or buckle under load and can hinder compaction, offering less reliable interlock than truly angular particles. So the property described is angular aggregate.