Characteristics of Load Bearing Masonry Construction

Load bearing masonry construction is a building technique in which wall elements are used as the framework of a structure.

Masonry is a well-established, old method that is mostly used to construct small buildings. Over the years, evolution in materials and engineering has made load bearing masonry construction a reliable technique to build larger structures capable of standing the test of time.

The masonry units are places as layers once at a time and they are held together by a binder (mortar) which highly affects the mechanical properties of the wall. Cement mortars, lime mortars or synthetic adhesives can be utilized.

The superstructure loads are transferred from the bearing walls to the foundation of the building and, subsequently, to the ground. The types of load-bearing masonry construction are the following:

1. Masonry walls made of stones, bricks or blocks: The masonry units are constructed by bricks, concrete blocks of stones. This technique can be utilized for either interior or exterior walls.
2. Masonry walls made of a single or a composite material: In this type of masonry construction, a single or a composite material bear the applied loads. The composite material method provides esthetic quality while being quite economical.
3. Reinforced or Non-Reinforced Masonry Construction: To withstand the compressive and tensile stresses applied, steel reinforcement can be used in the masonry units. Non-reinforced walls address severe issues with tensile forces. They usually develop cracking and present serviceability problems.
4. Cavity Masonry Construction: This technique involves the construction of two walls separated by a cavity. Cavity walls  that have reduced weight, act as a reliable sound insulation and demand lower maintenance. 

Why should load-bearing masonry be selected? Which are its benefits and drawbacks?

Advantages of load-bearing masonry:

• All types of load-bearing masonry provide substantial fire resistance.
• Masonry buildings are more esthetically appealing. The materials used are available in different colors and textures providing numerous choices.
• The construction procedure is simple and the materials needed are economical.
• The bearing-load structure provides high durability and strength to the building.
• Load-bearing masonry does not require a time-consuming preparation to be implemented.

Drawbacks of load-bearing masonry:

• Load bearing masonry demands more man-hours to be constructed and is a slower procedure than other construction methods.
• The total weight of the masonry walls is high.
• Masonry units do not provide adequate thermal insulation.
• Load-bearing masonry does not perform well in earthquake loads. In particular, non-reinforced units cannot withdraw the high tensile and shear stresses and experience a brittle failure that can prove to be catastrophic.

Source: Theconstructor.org