ABSTRACT
The present study discusses the frictional behaviour of porous recycled rubber used for a wide variety of architectural applications as flooring tiles. This type of flooring tiles, of the relatively high resilience, are used in schools, boutiques, hospitals, offices, conference rooms, homes, trade fair stands and homes for the aged. Experiments were carried out by the sliding of the bare foot and rubber footwear against the tested rubber tiles of different porosity, where friction coefficient was tested. A test rig was designed and manufactured for the test. Loads were applied by foot up to 300 N. The normal and friction forces were measured to determine the static friction coefficient.
Based on the experimental observations, it was found that friction coefficient displayed by bare foot sliding against dry recycled rubber tiles slightly increased with increasing force reduction ratio. It seems that the presence of pores inside the rubber matrix is responsible for the extra deformation displayed by the porous recycled rubber and consequently the contact area between the foot and the tested flooring materials increased. When rubber shoe slid against dry rubber tiles friction coefficient significantly increased with increasing the force reduction ratio due to the increased deformation of the rubber tiles. No significant effect was observed for increasing the normal load.
Besides, sliding against water wetted rubber tiles showed significant decrease in friction coefficient. This behavior can be attributed to the porosity of the rubber which works as water reservoirs storing the water and feeding it up to the contact area when the normal load is applying on the rubber tiles. Friction coefficient displayed by shoe showed higher friction coefficient. In the presence of detergent between the sliding surfaces friction coefficient drastically decreased to values lower than that displayed by water. Rubber shoe showed significant friction increase compared to that observed for bare foot. In addition, drastic friction decrease was observed for bare foot sliding against oil lubricated tiles. According to the European legislations the sliding condition can be considered as very slippery. Friction coefficient displayed by shoe displayed relatively higher friction values than bare foot.