High Performance

Penn State Millennium Science Complex, University Park, Pennsylvania, features cantilevered architectural precast finished in brick.

Precast concrete helps create high-performance buildings through integrated design strategies, balancing efficiencies for all of the building’s materials, systems, and design. High-performance buildings combine energy efficiency, low cost, high durability (or service life), space flexibility, low environmental impact, and high quality of life. Choices in one area impact other areas, requiring all systems to be considered together. Some of the ways that precast concrete can contribute to high-performance buildings include:

• Precast concrete walls act as thermal storage to delay and reduce peak thermal loads.
• Precast concrete walls used with insulation provide energy benefits that exceed the benefits of mass or insulation used alone in most climates.
• Precast concrete sandwich wall panels used as an interior surface can save material by eliminating the need for framing and drywall.
• Precast concrete walls can be designed to be disassembled for building-function changes, saving material and extending the service life of the panels.
• Precast concrete’s durability creates a long life-cycle and low maintenance, which creates less need for replacement and maintenance during the building’s life.
• As a plant-cast product manufactured under tight quality controls, precast concrete eliminates any construction waste and minimizes transportation and disposal costs.

In addition, precast concrete aids high-performance designs by incorporating these sustainable concepts:

Reduction in the amount of material used and the toxicity of waste materials

Recent innovations such as CarbonCast® carbon fiber reinforcement allow precast concrete to be optimized so less concrete is needed, yet the components are lighter in weight and more durable than conventional precast. Industrial wastes such as slag cement and silica fume can be incorporated into the mix, replacing up to half of Portland cement. As a manufactured product created under controlled conditions in the plant, precast concrete generates low amounts of waste, and the waste generated has low toxicity.

Reuse and repair of products

Precast concrete panels can be reused when buildings are expanded. Because the precast process is self-contained, formwork and finishing materials are reused. Wood or fiberglass forms can generally be used 40 to 50 times without major maintenance, while concrete and steel forms have practically unlimited service lives.

Recycle and reuse of products with recycled content

Concrete can be recycled as fill or road base. Wood and steel forms are recycled when they become worn or obsolete. Virtually all reinforcing steel is made from recycled steel. Many cement plants burn waste-derived fuels such as spent solvents, used oils and tires.