In the next 50 years we are going to make more progress along several current initiatives. First, sustainability may be the sleeping giant. To take greater advantage of recycling, we will have to figure out how to handle a wide variety of cementitious materials and recycled aggregates without having to reinvent the wheel and customize every concrete mix with every variation in the material input stream. We will have to exploit concrete's natural advantage of being able to turn local materials into a robust building material (and thus minimize transport costs and energy consumption) by finding ways to effectively use marginal materials such as reactive aggregates.

Likewise, the reality of global warming will settle in, and with energy costs, will compel more efficient cement use. Further, sustainability demands that we stop building expensive temporary structures out of wood (the formwork) and then scrapping them after casting slightly less expensive permanent structures out of concrete and steel. Sustainability will also be enhanced as we double or triple service life by using sound design details and materials and construction practice.

Second, recent attention to performance specifications is highlighting the need for tests that reliably measure the characteristics of concrete that really matter and that owners are willing to pay for. Let's hope that the next 50 years see the going-away party for slump and air tests as we know them, and the welcome party for fast, dependable ways to assess concrete while it is still on the truck for potential workability, strength, and durability.

We also need innovation in reliable ways to evaluate and project the durability of hardened concrete, and to build those test results into practical models for predicting service life. If we want to elevate the state of field practice, we need more direct and quantitative linkages between placing, consolidating, finishing, curing, and thermal protection and the in-place concrete properties that such “good practice” is intended to foster. We should also plan on having high-strength, non-brittle concrete, which will compete with structural plastics as they come to market.

—Ken Hover

Read more prognostications by industry leaders on the next 50 years of concrete.