Dreizler, Siegfried;

Spacer for reinforcements

A spacer for reinforcements has a body made of polymer concrete, with the polymer concrete consisting of a cured plastic material into which aggregates in the form of grains are integrated. The surface is post-treated in such a way that grains project from the surface of said cured plastic material, making possible an intimate chemical and physical bound with a cement paste of a concrete mass in which the spacer is to be embedded.

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What is claimed is:

1. A spacer for positioning reinforcements, said spacer comprising:

a body made of polymer concrete consisting of a cured plastic material having aggregates in the form of grains integrated in and dispersed throughout said plastic material, said body being adapted to be embedded in cementitious material for positioning said reinforcements within and in spaced relation to the exterior surface of said cementitious material,

a predetermined surface of said body being characterized by a portion of cured plastic material having been detached from the exterior of said body whereby portions of random ones of said grains are exposed and project from said cured plastic material and whereby random craters are formed in said surface to interlock with said cementitious material and to form a moisture sealed bond.

2. The spacer of claim 1, wherein said grains are fractured quartz grains and said portions of said grains form undercut regions to receive said cementitious material and form an intimate interlock therewith.

3. The spacer of claim 1, wherein said aggregates and said plastic material have densities such that the aggregates sink into said polymer concrete during curing whereby to form a spacer body having a generally smooth exterior.

4. The spacer of claim 3, wherein the predetermined surface of said body is characterized by a portion of the generally smooth exterior of said cured plastic material having been detached by sand blasting, at least in part and in place, whereby to expose said portions of said grains.

5. The spacer of claim 3, wherein said predetermined surface of said body being characterized by a portion of the generally smooth exterior of said cured plastic material having been detached by chemical dissolution, at least in part and in place, whereby to expose said portions of said grains.

6. The spacer of claim 1, wherein

a retaining element for engaging and positioning a reinforcement is secured to said body, said retaining element having a first portion embedded in said cured plastic material and a second portion projecting outwardly from the predetermined surface of said body, and

said body, including said retaining element, is adapted to be embedded within the cementitious material, the second end portion of said retaining element extending to a location remote to the exterior of said cured plastic material for engaging and positioning a reinforcement interiorly of said cementitious material, the interlocking engagement between said predetermined surface and the cementitious material inhibiting moisture from the exterior of said cementitious material from reaching said reinforcement.

7. A spacer for positioning a reinforcement relative to a mold form into which liquid concrete will be poured and allowed to harden about said spacer and said reinforcement, said spacer comprising:

a body comprised of a plurality of quartz grains interbonded and cured in place in a polymer concrete and having an exposed surface,

said exposed surface resulting from a predetermined amount of the cured polymer concrete having been removed from said body in an amount such that exposed portions of said grains project from said exposed surface and such that randomly positioned craters are formed in said surface to form areas of chemical and mechanical attachment for the poured concrete.

8. A spacer for a reinforcement and adapted to be embedded into a mass of cementitious material, said spacer comprising

a body made of polymer concrete consisting of a cured plastic material having aggregates in the form of grains dispersed generally uniformly throughout said material,

a predetermined surface of said body being characterized by a portion of said cured plastic material having been removed in place from said body to expose at least some of said grains and form craters to interlock with said cementitious material and to form a moisture sealed bond therewith, said exposed grains projecting in part from said predetermined surface of said cured plastic material and said craters extending into said predetermined surface.

9. A spacer for positioning a reinforcement relative to a mold form into which liquid concrete will be poured and allowed to harden about the spacer and the reinforcement, said spacer comprising

a body comprised of a plurality of quartz grains interbonded and cured in place in a polymer concrete and having a generally smooth exterior surface,

said grains being relatively uniformly dispersed in said polymer concrete and disposed below the exterior surface of said body, and

a portion of said exterior surface having been post-treated by removal of a predetermined amount of said cured polymer concrete in such a way as to form a nonsmooth surface and to expose portions of at least some of said grains, said exposed portions of said grains projecting from said nonsmooth surface to form areas of chemical attachment to the poured liquid concrete.

10. A spacer for ensuring accurate positioning of a reinforcement within a form into which liquid concrete will be poured and allowed to harden whereby the reinforcement will be at a predetermined distance for the exterior surface of the concrete element produced in said form, said spacer comprising

a body made of polymer concrete consisting of a cured plastic material having aggregates in the form of grains integrated in and dispersed throughout said plastic material, said resulting body having a generally smooth surface consisting of cured plastic material and said grains comprising fractured quartz,

a predetermined surface of said body being post-treated by removal of cured plastic material from said smooth surface in such a way that exposed portions of random ones of said grains project from the predetermined surface of said cured plastic material, said exposed projecting grains allowing a chemical attachment with the liquid concrete.