Tag Archives: concrete

Liquid calcium carbonate

Geologist Adam Wallace reports in ‘Science’ that calcium carbonate has a dense liquid phase

Computer simulations could help scientists make sense of a recently observed and puzzling wrinkle in one of nature’s most important chemical processes. It turns out that calcium carbonate — the ubiquitous compound that is a major component of seashells, limestone, concrete, antacids and other naturally and industrially produced substances — may momentarily exist in liquid form as it crystallizes from solution.

“Our simulations suggest the existence of a dense liquid form of calcium carbonate,” said co-corresponding author Adam Wallace, an assistant professor of geological sciences in UD’s College of Earth, Ocean, and Environment who conducted the research while a postdoctoral researcher at the Lawrence Berkeley National Laboratory. “This is important because it is an as-yet unappreciated component of the carbon cycle.” (more…)

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Monitoring concrete

UD professors study microbes as potential biomarkers for damaged concrete

Concrete is the most widely used construction material in the world. However, many concrete roadways and bridges crack due to internal chemical reactions, temperature fluctuations or external chemical and physical stresses.

One internal chemical reaction is the Alkali-Silica Reaction (ASR) that destroys the concrete from within.  (more…)

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UA Professor Uses Aerospace Materials to Build Endless Green Pipeline

Carbon fiber fabric and lightweight honeycomb materials, plus a mobile manufacturing platform, make infinite pipeline technology cheaper and greener while boosting local economies.

Mo Ehsani, professor emeritus of civil engineering at the University of Arizona, has designed a new, lightweight underground pipe he says could transform the pipeline construction industry.

Instead of conventional concrete or steel, Ehsani’s new pipe consists of a central layer of lightweight plastic honeycomb, similar to that used in the aerospace industry, sandwiched between layers of resin-saturated carbon fiber fabric. (more…)

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