The establishment of a safety code for walkway surfaces has been materially handicapped by the lack of an ad equate m ethod of measuring slipperiness. The m echanics of walk in g a r elated to slippin g and the design of tes ting in struments are briefl y disc ussed . In order to test floors in actual service a portable slipperin ess tester of the pendulum-impact type was designed a nd construc ted. The design is based on the prem ise t hat, in the process of ordinary wal king, slipping is most likely to occur when the walkway surface is fir s t contacted by t he edge of the hee l. The instrument and test procedure are de cribed . The effects of varying some of t he constants of t he instrument, such as t h e angle of contact between t he te t heel and t he walkway surface, and t he pressure between t he hee l and the walkway, are disc ussed. T ypical resul ts obtain ed with both rubber and leather test heels and und er both dry and wet condi tio ns a re given for various fl ooring and fini shi ng materials.In ge neral, t he t raction furni shed b y dry rubber heels is much better t han that obtain cd with dry leather heels. Man y walkway surfaces are hazardous wh en wet. Good antislip proper ties under wet condi t ions are usuall y a ssociated with rough particles that p roject through t he film of watcr a nd thu p revent it. action a s a lubricant.

The resistance of bituminous built-up roofing membranes to thermally induced forces is considered in terms of their strength properties such as breaking load in tension, modulus of elongation and apparent linear thermal expansion coefficient. The development of a Thermal-Shock Resistance Factor is described and values are given for three bituminous built-up membranes at temperatures of -30 °F (-34.4 °C), 0 °F (-17.8 °C), 30 °r (-1.1 °C) and 73 °F (22.8 °C). The apparent relation between the values obtained in the laboratory and the observed performance of roofing membranes in service is considered. The utilization of the Thermal-Shock Resistance Factor in the reduction of potential failures of bituminous built-up roofing membranes in service from thermally induced forces is also discussed.

The resistance of bituminous built-up roofing membranes to thermally induced forces is considered in terms of their strength properties such as breaking load in tension, modulus of elongation, and apparent linear-thermal-expansion coefficient. The development of a thermal-shock-resistance factor is described and values are given for three bituminous built-up membranes at temperatures of -30 F (-34.4 C), 0 F (-17.8 C), 30 F (-1.1 C), and 73 F (22.8 C). The apparent relation between the values obtained in the laboratory and the observed performance of roofing membranes in service is considered. The utilization of the thermal-shock-resistance factor in the reduction of potential failures of bituminous built-up roofing membranes in service from thermally induced forces is also discussed.

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