Nanoscale studies of cement chemistry with 15N resonance reaction analysis

Analyses of materials with ion beams have proven to be a valuable technique for describing the spatial distributions of specific elements in host materials. We have applied this technique using the 15N(p, αγ)12C reaction to study the time dependence of the chemical reactions involved in the curing of cement. By using the Dynamitron Tandem accelerator at the Ruhr Universität, Bochum, Germany, we have been able to achieve a few nanometer spatial resolution at the surface of cement grains and to study the hydrogen distributions to a depth of about 2 μm. By applying a technique for stopping the chemical reactions at arbitrary times, the time dependence of the chemical reactions involving specific components of cement can be investigated. In addition, the effects of additives on the chemical reactions have been studied, as have materials that are components of concrete.