Overview of Canadian Practices in Architectural Precast Concrete for Building Facades

Abstract

T he buildings we construct reflect strongly the values, needs and aspirations of the culture that we live in. All our notable new works are built upon a firm base of past experience using current science and technology. In the Canadian construction market, cladding materials (masonry, glass, metal, stone, stucco, tile and precast concrete) compete vigorously for a share of the $35 billion (Canadian) being spent annually on building construction. Architectural precast concrete encompasses all precast concrete units employed as elements of architectural design. Such units can be structural, loadbearing by themselves, act as permanent formwork for cast-in-place concrete or be mainly decorative, The ability of concrete to flow and assume the contours of its mold, combined with the enormous number of finishes and textures which can be produced on the face of architectural precast concrete panels, gives a designer tremendous freedom to select the color, texture and shape he/she wishes to impart to his/her building. High quality precast concrete produced in a plant under controlled conditions is extremely durable and resistant to weathering and abrasion. The effects of weathering, dirt accumulation and air pollution can he minimized by careful consideration of how rainwater will flow down the face of a building. The provision of drips, channels and scuppers can be used to direct this flow. Penetrating sealers are often used to repel water from absorbent surfaces, particularly where soft aggregates and a light colored matrix is used.