Engineered composite building materials and methods of making same

摘要

An engineered composite building material, such as fiber cement, having one or more engineered sub-surface regions designed to provide the building material with improved moisture ingress resistance, paint adhesion, and other mechanical properties is provided. The sub-surface region has a cement-polymer matrix formed by introducing an impregnating agent into the pores of the substrate. The composite building material may be formed by applying impregnating agents to the subsurface regions of the substrate to form chemical and/or mechanical bonds with the matrix of the building material, the reinforcement fibers, and/or the surface coatings applied to the material. The thickness of the sub-surface regions may be controlled by varying the viscosity and porosity of the building material substrate. The cement-polymer building material has enhanced durability, weather resistance, strength, and stiffness.

主权项

1. An engineered composite building material comprising:
a porous fiber cement substrate having an exterior fiber cement layer, and a subsurface layer, the subsurface layer comprising fiber cement and a polymeric impregnating agent, wherein the polymeric impregnating agent is chemically bonded to hydroxyl functional groups in the fiber cement; and a coating applied to the exterior fiber cement layer wherein a portion of the coating penetrates the subsurface layer and forms a chemical bond with the polymeric impregnating agent, wherein the composition of the polymeric impregnating agent is different from the composition of the coating, wherein the polymeric impregnating agent and the coating cause the density of the subsurface region to be greater than the density of the exterior fiber cement layer.