The purpose of this paper is to investigate static friction between roofing materials, and snow on roof in general.
This report deals with the results of experimental study on a slant type static friction between staple roofing materials and ice blocks as a sliding mass.
Eight specimens for this examination as staple roofing materials were selected by the condition of surface roughness and surface hardness.
The temperature condition of this experiment have 4 levels as -10°C, -5°C, -1°C and 3°C.
The results on the coefficient of static friction (μs) are summerized as follows
(1) μs depends remarkably on the kind of roofing material and experiment temperature. In those experiments on eight speciments and 4 levels temperature, the maximum value of μs as dry friction was 0.70 and the minimum was 0.04.
(2) Scatter in the measured values of μs was larger in specimens with large μs than small ones.
(3) As for surface conditions of roofing materials, μs depended principally on shapes of rogh-ness and scarcely on hardness.
(4) As for experiment temperature, μs values in the range from -10°C to 0°C declined generlly with temperature rise and those change curves in μs-T diagram were divided into 3 types.

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