Strengthening the Masonry Workforce Through Post-tensioning
Photos courtesy of Cercorp Initiatives
Like two variables in a simple equation, technology and the workforce each directly affect the total solution that, in this case, is the state of the industry and its ability to meet market demand. By changing one of these variables in relation to the other, the industry is impacted in either a positive or negative way. As a result, there are only two possible ways to positively impact the industry: 1) increase the number of skilled workers in the labor pool; or 2) reconfigure the technology to accommodate the changing labor pool. Of course, in both cases, it is essential to bear in mind that any change must serve the masonry industry. In other words, neither factor can be radically changed so as to create an entirely new industry as in the case of pre-cast and cast-in-place tilt-up construction.
Over the last decade or so, the industry has largely focused on workforce development as a means to maintain its market share. Although little attention has been paid to developing new masonry technologies, one such innovation offering great promise has emerged.
The FlexLock? Solution
The FlexLock Wall System
FlexLock construction begins by installing anchors into the footing. Because footings vary, the first course is laid in mortar. This is the only time mortar is used. With the first course in place, all-thread tendon segments are connected to the anchors by means of a coupling. These are typically spaced about 4' on center. The interlocking units are then dry-stacked. A slot in the unit enables the mason to place the block around the tendon without having to lift it over the top. Grout is not used in the vertical cores.
This method of post-tensioning is unique to FlexLock. The units are precision ground on the top and bottom to 0.015" preventing point loading, making post-tensioning possible. The system accommodates non-modular construction, jambs, sills, lintels, pilasters, and can be matted to conventional masonry. At the top of the wall, a bond beam is laid, reinforced and grouted with post-tensioning accomplished within, or on top of, the bond unit. Cercorp has extensively tested the FlexLock System and found it to have three to four times the reserve strength of standard masonry.
A Case Study
To assess both the speed of construction and the composite workforce, Cercorp, working with the engineering firm of Ryan-Biggs Associates and the International Masonry Institute (IMI), built a small test structure. The building, along with some test panels, were constructed with IMI students at their apprentice training facility in Cascade, Md. The instructors began by laying out the first course, after which the students built up the leads and courses. The students were each timed by Cercorp at laying approximately 100-125 units per hour, with material handling being the primary limiting factor. As the walls were laid up, the instructor walked around with a level and dead blow hammer ensuring that the walls were plumb, and window and door opening were in the right place. From this test, Cercorp concludes that FlexLock can dramatically increase productivity.
For the masonry industry to expand its markets, it has to balance the equation between the workforce and technology. The FlexLock Wall System, with its unique post-tensioning technology, enables mason contractors to reconfigure the available labor pool to increase both productivity and profitability.
For more information and availability, visit Cercorp's web site at www.cercorp.com.
About the Author
Dominic Cerrato is a freelance writer and CEO of Cercorp Initiatives, Inc. (www.cercorp.com). Cercorp develops and licenses technology in the masonry industry.