Fiber reinforced building products and method of producing same

Abstract

A fibrous reinforcing element made from oriented polyolefin material for reinforcing a matrix material such as cement has longitudinally varying cross-sections and frayed surface portions from which fibrils extend. The element has cross-sections which vary along its length, a characteristic which combines with the fibrils of the frayed surface portions to facilitate anchoring of the element in the matrix. The anchoring and strength characteristics make the element particularly useful for constructing cement building products or any product produced from a matrix binding agent. The element is in the form of a fiber made from a polyolefin film which is stretched at least fifteen times and then cut by cutting means along lines at least partially transverse to the direction of orientation. In the preferred embodiment a building product formed from a matrix of Portland cement has dispersed therein, a plurality of fibrous reinforcing elements at least a portion of which are the individual polyolefin fibers described in accordance with the invention. By uniquely providing a combination of the inventive fibers with fibers of other types within the cement matrix, improved anchoring and dispersion of the fibers is achieved, while the improved strength characteristics of the elements contributes to a building product of unusually improved strength.