Introduction to Concrete Masonry and Pavers

About this course.

A concrete masonry unit (CMU), commonly called a block, is a masonry unit made from cement, aggregate and water, formed under pressure and cured rather than fired, and laid in mortar to build walls in the same family of construction as brickwork. Blocks are larger than bricks — designed to be laid with two hands — so they build walls quickly and economically, and they come in a wide range of types, sizes and shapes to suit structural, appearance and performance needs. Understanding the main types is the starting point for using concrete masonry well, because a block suited to a garden wall differs from one suited to a load-bearing, reinforced structural wall.

Concrete blocks are distinguished first by whether they are hollow or solid. Hollow blocks have voids (cores) running through them, which reduce weight, save material and, importantly, create vertical channels that can be filled with grout and steel reinforcement to make reinforced masonry (Module 3). Hollow blocks are the workhorse of structural blockwork. Solid blocks (and part-solid units) have no significant voids and are used where the cores are not needed. The presence of cores is one of the defining features of concrete masonry, because it is what allows blockwork to be reinforced so readily.