Recycling Tires as Stay-in-Place Forms for Pavers

摘要

One of the challenges of quickly casting a large number of pavers inexpensively is the requirement that the forming equipment be used efficiently. In circumstances such as casting multiple pavers for cable-connected, concrete mat it is not generally practical to use block forming machinery. Production is limited by the number of available forms, the time required to assemble the forms, and the time needed to demold the hardened pavers. One solution to these problems that works for making large round pavers for low volume roadways or for erosion control is to use stay-in-place forms made by slicing scrap tires longitudinally through the tread. While the size of the paver is restricted to the size of the scrap tires that are available; the wide variety of tires being produced makes it possible to locate convenient sizes for a specific application.rnConstructing the forms is very simple in that it is only necessary to lay the half of the tire carcass with the rim hole down on a flat surface and anchor it so that it will not float up when concrete is placed in the interior and screeded to form the upper paver surface. In the case of articulated mat, the tire can be held flat by anchoring the cable that is preplaced through the rows of tire carcasses. Forms for individual pavers are constructed by attaching a piece of plywood to the sidewall of the half tire using screws driven trough the plywood backing into the tire sidewall.rnWhen the concrete is placed in the tire and consolidated with a conventional concrete vibrator; the concrete flows through the rim-hole and forms a "button" on the back of the half tire so the tire carcass is permanently attached to the paver. Since a minimum of assets are tied up in the forms, conventional moisture curing of the concrete is a practical option.rnThe small volumes of concrete used and the inexpensive nature of the forms make it reasonable to have these available in a casting yard to make use of excess concrete that would otherwise be discarded. In addition to allowing for the use of materials that would otherwise be discarded (tire carcasses and excess concrete); the reinforcement provided by the tire carcass results in a more durable paver.