Less weight helps make concrete more “labor friendly”. The best example of lightweight concrete and ergonomics is with concrete masonry. The Center for Infrastructure Research, University of Nebraska at Lincoln reported that many of the mason’s long-term health problems stem from heavy concrete masonry units.
“Concrete masonry is a dominant material in wall construction. Over $10 billion worth of masonry walls are constructed in the United States every year. However, the industry is facing a shortage of qualified masons, and the average age of active masons has been gradually increasing due, in part, to the hard work they have to do in lifting heavy concrete masonry units. The load of lifting these blocks, day after day, can make drudgery out of a day’s work for a mason especially after many years. Some masons must retire early due to the heavy lifting, and many masons experience crippling back and shoulder injuries before retirement”.
This continual loss of skilled labor is expensive to replace and may ultimately make concrete masonry non-competitive and less sustainable. By reducing the weight of concrete masonry and other concrete products that must be physically handled by labor we enhance sustainability to our workforce. It is common knowledge that lighter components have a positive effect on constructability as reported in ESCSI Info Sheet 3650.3, 1996:
At the same strength, lightweight concrete masonry units are up to 40% lighter than traditional concrete masonry units. Less weight minimizes the physical demands on masons and equipment, resulting in fewer injuries and worker’ compensation claims. Repeatedly lifting less weight extends a mason’s career, and allows women and men to work efficiently. Concrete masonry units that weigh less will increase mason productivity up to 21% on 8x8x16″ units, and 55% on 12x8x16″ units. Increase productivity means earlier completion and lower overhead costs. Even though a mason will lay approximately 20% more wall area in a year, the mason still lifts 15% less weight (about 94 less tons per year).
Less weight extends equipment life because lighter loads mean less wear and tear and helps insure safer scaffolding and worker platforms. Less weight means it is easier to meet OSHA weight requirements.