Coefficient of static friction for wood bulkheads on building floors

The coefficient of static friction was determined for Douglas fir wood on smooth concrete, rough concrete, asphalt, and packed soil. The effect of debris on some of the surfaces was also determined. The mean coefficient was 0.58 for smooth concrete, 0.81 for loads parallel to sweep marks on rough concrete, 0.86 for loads perpendicular to sweep marks on rough concrete, 0.76 for asphalt, and 0.58 for packed soil. Maximum design values of 0.5 for smooth concrete and packed soil and 0.6 for rough concrete and asphalt are suggested. The presence of soil or soybeans on the floor surface significantly reduced the coefficient and should be avoided