Pneumatic rock drill vs. electric rotary hammer drill: Productivity, vibration, dust, and noise when drilling into concrete.

Objectives: Both pneumatic rock drills and electric rotary hammer drills are used for drilling large holes (e.g., 10-20 mm diameter) into concrete for structural upgrades to buildings, highways, bridges, and airport tarmacs. However, little is known about the differences in productivity, and exposures to noise, handle vibration, and dust between the two types of drills. The aim of this study was to compare these outcomes with similar mass electric rotary and pneumatic rock drills drilling into concrete block on a test bench system.
Method: Three experiments were conducted on a test bench system to compare an electric (8.3 kg) and pneumatic drill (8.6 kg) on (1) noise and handle vibration, (2) respirable silica dust, and (3) drilling productivity. The test bench system repeatedly drilled 19 mm diameter x 100 mm depth holes into cured concrete block while the respective exposure levels were measured following ISO standards.
Results: Productivity levels were similar between the electric and the pneumatic drill (9.09 mm/s vs. 8.69 mm/s ROP; p = 0.15). However, peak noise (L _Peak : 117.7 vs. 139.4 dBC; p = 0.001), weighted total handle vibration (a _hw : 7.15 vs. 39.14 m/s ² ; p = 0.002), and respirable silica dust levels (0.55 vs. 22.23 mg/m ³ ; p = 0.003) were significantly lower for the electric than the pneumatic drill.
Discussion: While there were no differences in drilling productivity between an electric and pneumatic drill of similar mass, there were substantial differences in exposure levels of noise, handle vibration, and respirable silica dust. Structural contractors should switch from pneumatic rock drills to electric rotary hammer drills for structural drilling into concrete in order to reduce worker exposures to the hazards of noise, hand vibration, and silica dust.
(Copyright © 2018. Published by Elsevier Ltd.)