I’m a civil engineer with an energy development company. One of our projects in Colorado will require a concrete batch plant in a remote area. We are considering using well water for the mixtures, but we know the water is not potable. According to ACI 318-08, Section 3.4.2,1 “Mixing water for prestressed concrete or for concrete that will contain aluminum embedments, including that portion of mixing water contributed in the form of free moisture on aggregates, shall not contain deleterious amounts of chloride ion.

The author describes a new structural system that combines a stress-ribbon design with arches. Details about the architectural and structural solution, static and dynamic analyses, and the process of construction are included. The advantage of this structural system is demonstrated by several examples built in the Czech Republic.

Significant environmental advantages will be realized if industrial byproducts, such as fly ash, can be substituted in structural grade concrete. In the early 1990s, researchers at Montana State University/Western Transportation Institute (MSU/WTI) began investigating the feasibility of using industrial byproducts to produce concrete building materials. While the magnitude and nature of the projects at MSU/WTI have changed over the years, a common factor has been the use of fly ash as the sole binder in the concrete mixtures. This article details projects that have been constructed with this "fly ash concrete."