By Kyle Weatherly, Carolina Stalite Company
Masonry has been used as a means of construction for centuries dating
back to early civilization. Many of the world’s most iconic structures have been constructed with masonry. Building methods evolved, and manufactured concrete block began being used in the United States in 1900 when Harmon S. Palmer invented a machine that could produce concrete masonry units (CMU). These blocks, while innovative, were also heavy to handle.
This issue was solved in 1923 when Dan F. Survey, of Kansas City, introduced the first masonry block employing lightweight expanded shale as the aggregate. Lightweight CMUs quickly achieved popularity among both block manufacturers and users of the end product. As the product developed, other types of materials were found to have similar characteristic to expanded shale after they were processed in a similar manner. Today rotary kiln expanded shales clays and slates (ESCS) have similar properties and performance and are in the same classification of lightweight aggregates.
The advantages of ESCS Lightweight CMUs are numerous with a few of them highlighted below.
- Easier Handling and Transportation: Lightweight CMUs are easier to handle and transport than their traditional counterparts. This reduces the labor costs and the time needed for transportation and installation. Builders and construction crews can move and place these blocks more efficiently, speeding up the construction process and reducing overall project timelines.
- Cost-Effective Construction: Due to the reduced weight, less labor is required for lifting and positioning the blocks, which can lower construction costs. The ease of handling translates into faster build times and fewer labor-intensive operations, which ultimately contributes to overall cost savings, especially important in budget-conscious school construction projects.
- Reduced Structural Load: Lightweight CMUs exert less weight on the building’s foundation and structure. This can reduce the need for heavy or complex structural reinforcement, making it easier and cheaper to meet building codes. This feature is particularly beneficial in areas prone to earthquakes or high winds, where structural integrity is a concern.
- Improved Thermal Performance: Some lightweight CMUs can have improved insulating properties, contributing to better thermal efficiency. They can help to regulate indoor temperatures more effectively, reducing the load on the HVAC system and improving the building’s energy efficiency. This improved thermal performance leads to improved fire ratings when compared to a block made with normal weight aggregates.
In short, ESCS lightweight CMUs combine the benefits of durability, energy efficiency, and strength with the added advantage of ease of construction and handling, making them a practical and efficient choice for buildings that require both safety and cost-effectiveness.
