Elastomeric composite pavement
AssigneeThe Johnson Rubber Company
InventorDennis M. Lucik
Life of this patent
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Abstract
A premium paving unit of elastomeric binder material and friction aggregate formed by a molding method which results in an ideal distribution of the aggregate in the binder wherein the aggregate is exposed at a wear face of the unit, has a preferential orientation with the wear face, and is substantially uniformly distributed throughout the remainder of the unit.
Claims10
A method of making a paving unit comprising the steps of providing a closed mold cavity having dimensions generally corresponding to the dimensions of the finished paving unit, a major planar wall of the mold cavity being formed of compliant material, introducing friction aggregate and settable elastomeric binder material into the mold cavity, compressing the elastomeric binder material with the friction aggregate substantially uniformly dispersed therethrough against the compliant wall under suitable conditions of temperature and pressure to cause the aggregate particles immediately adjacent the compliant wall to locally embed themselves into the compliant wall and effectively exclude the elastomeric binder material from the zones of embedment of the aggregate particles in the compliant wall, allowing the elastomeric binder material to set in the mold, thereafter removing the molded unit from the mold cavity with the face of the unit which formerly contacted the compliant wall exhibiting a textured wear surface wherein the outermost aggregate particles of this face protrude slightly from adjacent areas of elastomeric binder material and the protruding areas of these outermost particles are substantially free of any coating of elastomeric binder material.
A method of making a paving unit comprising the steps of laying up a layer of aggregate against a surface defining a plane in a manner wherein a portion of the aggregate is in direct surface-to-surface contact with said plane defining surface, flowing a settable elastomeric material into the interstices of the aggregate layer to an extent that substantially all of the volume of interstices is filled with such elastomeric binder material, said elastomeric binder material being caused to enter and fill the interstices in a manner which avoids significant disruption of the previously established surface-to-surface contact between said aggregate and said plane defining surface while areas of said plane defining surface not contacted by said aggregate are contacted by said settable material, allowing said settable material to set and thereafter removing the composite formed by said aggregate and binder material from said plane defining surface, said aggregate being selected of a material harder than the final hardness achieved by said settable material and providing frictional characteristics for said paving unit.
A molded paving block comprising an elastomeric composite body of predetermined thickness, said body comprising an elastomeric base and aggregate material dispersed in the base, the distribution of the aggregate being substantially uniform throughout the thickness of the block, said block having a molded wear surface at its upper face, the wear surface having a substantial fraction of its area formed by aggregate surface areas substantially free of any covering of the elastomeric base material, the individual aggregate particles providing said free surface areas being retained in said base material by embedment therein, the wear surface having its area remaining from that formed by said free surface areas being formed by the elastomeric base as a result of molding against a compliant cavity wall, the elastomeric base being excluded from said free surface areas of the aggregate by the interaction of the compliant cavity wall, elastomeric material and aggregate during the molding process, said free surface areas of aggregate being slightly raised above the surface of the elastomeric material as a result of the impression of such free surface areas into the compliant wall during the molding process.
Dependencies are inferred from the claim text.