Test Bench for Evaluating Concrete Drilling Methods (Completed – 2014-2019)
Drilling large holes into concrete is a physically demanding job associated with high levels of exposure to noise, silica dust, and hand forces and vibration. These exposures are associated with shoulder, arm and back fatigue, pain and musculoskeletal disorders; hand arm vibration disorders; noise induced hearing loss; and silicosis. There are ways to reduce these hazards. For example, using sharper bits or applying different forces while drilling can reduce handle vibration; using dust capture will reduce silica dust exposure; and drills have different technologies for reducing handle torque and vibration.
Unfortunately, there have been no systematic methods to evaluate these different drilling techniques. We have developed a laboratory-based, test bench robotic system that drives an active drill into concrete while simultaneously measuring these health-related exposures and productivity. The measurement methods follow guidelines from national and international standards. We systematically tested the following drilling techniques: (1) different levels of applied force, (2) different bit types, (3) different bit sharpness, (4) different dust capture systems, and (5) different drills. The different drilling techniques were compared on four health-related exposures: (1) handle torque, (2) handle vibration, (3) noise, and (4) respirable silica dust, plus productivity (rate of penetration (ROP)). Our research partners included the major tool manufacturers (e.g., HILTI, DeWALT, Bosch, DustControls), large regional contractors, and the Masonry r2p Partnership. The tool manufacturers provided advice on testing methods and methods to disseminate study findings. The findings were also summarized and disseminated to contractors and construction workers, using formats that are readily accessible, so that different drilling techniques can be easily compared on health and productivity measures. The findings are currently published on widely used web sites (e.g., ‘Work Safely with Silica’, eLCOSH, BAC), union publications (e.g., Bricklayers (BAC), Electrical Workers (IBEW), Laborers (LIUNA)), and at scientific conferences and journals. This proposal addressed several Strategic Goals of the NIOSH NORA 2 National Construction Agenda (2012): reduce silica exposure by increasing availability of controls and procedures (Impact Goal 5.0); hazards prevention through design (Impact Goal 13.0); reduce hearing loss (Development Goal 4.0); reduce the incidence and severity of work-related musculoskeletal disorders among construction workers (Development Goal 7.0); and dissemination and training (Development Goal 11.0).