Comparison of Properties of Masonry Walls Constructed with Commonly Used Bricks and Non-standard Large Bricks

Abstract

Brick masonry is a very popular construction material especially among the house builders, because of its better heat insulation properties, compressive strength, high durability, availability and the low cost. In Sri Lanka, brick masonry construction using commonly available burnt clay bricks (normal bricks), in different bond patterns can be seen in practice. However, the English bond is still considered to be the ideal bond pattern with normal bricks. Recently it has been noticed that a burnt clay brick with larger dimensions (non-standard brick) is gaining popularity in the local construction industry due to some advantages such as fast construction and reduction in the required mortar volume due to the reduced number of mortar joints. These larger bricks are used with a header bond pattern to build typical one brick thick walls. Although there are several benefits in using these larger bricks, it is important to determine the strength properties as well, since the strength of brick masonry highly depends on the strengths of brick units, mortar and the bond pattern. If these walls are used as load bearing walls or in-fill walls, the determination of strength properties is essential. The effect on strength properties due to the difference in bond pattern was addressed in this study. Experimental investigation was carried out to compare the strength properties of normal and non-standard brick units and corresponding brickwork in terms of compressive, flexural and shear strengths. Locally available normal brick and non-standard brick samples have been selected and tested according to the relevant standards to assess the strengths of bricks and brickwork. It was observed that the brickwork constructed with non-standard bricks has slightly higher compressive strength compared to brickwork with normal bricks. However flexural strength of masonry constructed with non-standard bricks with a header bond pattern is lower than the flexural strength of normal brick masonry which is constructed with the English bond pattern. Therefore, brickwork constructed with non-standard bricks is not efficient compared to normal brickwork, especially when the walls are subjected to lateral loads. This may be due to the weak bond in the brickwork constructed with non-standard bricks as the header bond pattern was used in them.