Chapter 31: Masonry units

Traditional unreinforced masonry can be considered a composite composed of two major elements: the unit and the mortar. Both elements are in many ways equal in importance, however the unit will always constitute a much greater proportion by volume of the masonry. This chapter concentrates on the unit (i.e. clay, concrete aggregate, aerated and reconstructed stone, calcium silicate and natural stone) element of the masonry and discusses the properties of these different types of units in relation to the codes with which each unit has to comply. The chapter also describes the most common manufacturing processes used in the UK for each unit and indicates the materials from which the units are composed. It is important to appreciate that the recently introduced codes for the specification of all masonry units are written as performance standards. As such, all requirements are based on the finished product.