A research team from Middle Tennessee State University (MTSU) is quantifying a method that measures the product’s effect as a power troweling aid. The research is focused on how chemicals applied to the slab during power troweling enables the finishing process to be easier.
Finishers commonly spray water onto the concrete’s surface to help draw up the “cream” to close up the surface and create a smooth finish. Adding water can lessen the surface’s durability. “The research is demonstrating that power troweling aids can be effective to decrease wear and tear on power trowel blades, and reduce worker fatigue without affecting final slab quality,” says David Loe, president of Lythic Solutions. The research is being conducted by staff and students of the MTSU’s Concrete Industry Management (CIM) Program. Power troweling aids have yet to be defined by ASTM or ACI. And there currently is no quantitative test method to assess a product’s claim to effectiveness during power troweling. Based on this initial effort, researchers are working on criteria that may lead to an ASTM-like procedure that will enable contractors to assess a power troweling aid’s effectiveness. The procedure not only includes jobsite productivity measurements, but quality tests on the hardened concrete surface.
Encouraged by the initial tests, MTSU researchers have scheduled additional contractor-focused tests at the World of Concrete. Contractors are invited to participate by finishing sections of freshly placed concrete in the Gold Lot. “We want to monitor the reaction of at least 20 experienced concrete finishers to develop our model test procedure for power trowel aids,” says Dr. Heather Brown, MTSU’s lead researcher. There will be at least two test periods each day, at 10:30 a.m. and 2:30 p.m. in the Gold Lot. Be sure to stop by and participate!
Initial Testing and Preliminary Findings
“Researchers placed a large slab, dividing the surface into three separate work areas. An experienced concrete contractor then finished the surface using a walk-behind power trowel under three different conditions,” explains Loe. “One condition called for the contractor to power trowel the surface without spraying water or a power troweling aid. The second allowed the contractor to add water to the surface during power-troweling. For the third condition, the contractor added a power troweling aid.”
Researchers monitored the power trowel’s engine RPM, blade setting, and operator comments describing resistance. After 28 days, researchers will examine cores and conduct durability tests. Lythic Solutions (Booth S12747), a Vancouver, Wash. material supplier, is sponsoring the MTSU research. “We feel that the MTSU research is a game-changer,” says Loe. “We consistently receive field reports from contractors on how some surface-applied products affect power troweling by making their jobs more productive. We are supporting MTSU’s efforts to help our contractors have a fair and consistent approach to reviewing this new product technology on their field work.”