Modern reinforced concrete emerged as the building material of choice towards the end of the nineteenth century, and prestressed concrete followed in the late 1920s as a special variation of structural concrete. Since then, the built environment has been shaped by concrete as by no other structural material. Although the design and construction of reinforced and prestressed concrete structures can be considered a "mature" field, with almost 100 years of experience to draw on, there are always new challenges to be overcome through research efforts.
Due to economic pressures or inadequate quality control, the service life of concrete structures is often not as long as would be desirable. Research can lead to design and construction alternatives that result in much more durable structures.
Another challenge is the capability of such structures to resist the effects of strong ground motion as experienced during earthquakes. And then there are the security and safety concerns of a public sensitized by recent terror attacks and natural disasters, which pose significant challenges to the research community to devise schemes of protecting our built environment against impact and blast loads, as well as other man-made and natural disasters.