Precast concrete: brute strength: the right materials can lower long-term building costs.

• Author: Kuckhahn, Tom
• Position: ADVICE / CONSTRUCTION

THE COST OF A COMMERCIAL building can be unpleasant. But paying twice? That is the experience of many building owners facing premature replacement costs and high maintenance expenses. There is good news, however, in durable building materials. Advancements in precast manufacturing make the long-term financial picture of concrete buildings stronger than ever.

Minimal maintenance, Durability depends upon the ability of a structure to endure over time. Concrete has proven to be an incredibly durable material throughout the course of history. Roman aqueducts made of concrete are still standing after nearly 2,000 years. This is possible because concrete does not oxidize as metals do. Unlike many natural materials, it is highly impermeable and it resists the weathering effects of water and chemicals. In the case of precast concrete made under plant-controlled conditions, it can have strengths that exceed those of natural stone, thus reducing chipping and breaking.

The strength of concrete is not only high, it is unique among building materials. While concrete gains most of its strength in the first 28 days, it continues to gain strength throughout its life. This is due to a process called "hydration," which is the interaction of individual grains of cement with water to form long molecular chains that literally "grab" surrounding particles. This process slows over time, but it does not end. The result is concrete that is not only strong but also very dense and impermeable. Precast concrete capitalizes further on these attributes because its early strength demands encourage cement manufactures to make cements with more, smaller grains, creating tighter, stronger structures. Because of these characteristics, concrete walls require minimal maintenance, which is especially welcome due to the price-sensitive nature of the construction market and the increasing costs of facility repair. An occasional, high-pressure wash is all that is needed to maintain a concrete finish. Re-caulking joints about every 15 years helps to eliminate fissures that may...