Reflective concrete body, process for the manufacture and utilization of the same
AssigneeInstitut fur Privatwirtschaft Gschwend & Stadler
InventorHeinrich Metzler
Life of this patent
Estimating the term…
Abstract
In a road surface and a process for making same, a top layer of reflex reflective concrete in slab or cylindrical form is made of a mixture of white Portland cement, particulate white quartz filler material, colorless crystal balls and titanium dioxide pigment. The quartz filler is a trigonal trapezohedrical .beta.-quartz powder having a refractive index of 1.55 and a particle size less than the glass ball diameters, the latter being from 0.2 to 0.6 mm. The glass balls constitute from 50 to 70% of the mixture and are arranged within the top layer of concrete in successive layers with those balls closest to the impact surface of the top layer being half exposed to intercept light from car headlamps.
Claims12
In a road surface having a top layer of reflex reflective concrete comprising a mixture of cement, hard filler material, glass balls and pigment, the improvement wherein:
- (a) said cement is white Portland cement;
- (b) said hard filler material is particulate white quartz of particle size smaller than that of said glass balls;
- (c) said glass balls are colorless crystal glass balls comprising from 50 to 70% of said mixture and being arranged in a plurality of layers within said top layer of said road surface, the balls of the uppermost of said plurality of layers being exposed approximately to half their diameters;
- and
- (d) said pigment is titanium dioxide.
In a process for manufacturing a road surface having a top layer of reflex reflective concrete, said top layer being formed by roughly mixing cement, hard filler material, glass balls and pigment in a dry condition, adding sufficient water to the dry mixture to produce a thick wet concrete, filling a form with said wet concrete, compacting said wet concrete in the form, removing the compacted concrete from the form, allowing the removed compacted concrete to harden and thereafter treating a surface area of the hardened concrete with an acid to partially expose those glass balls which are directly adjacent said surface area, the improvement comprising the steps of using white Portland cement as said cement, white quartz particles as said hard filler material, colorless crystal glass balls in an amount of from 50 to 70% of said dry mixture as said glass balls and titanium dioxide as said pigment.
Dependencies are inferred from the claim text.