TY - JOUR T1 - Nano-scale mechanics of colloidal C-S-H gels JF - Soft Matter Y1 - 2014 A1 - Enrico Masoero A1 - Emanuela Del Gado A1 - Roland Jean-Marc Pellenq A1 - Sidney Yip A1 - Franz-Josef Ulm AB -

Gels of calcium-silicate-hydrates (C-S-H) are the glue that is largely responsible for the mechanical properties of cement. Despite their practical relevance, their nano-scale structure and mechanics are still mainly unexplored, because of the difficulties in characterizing them in a complex material like cement. We propose a colloidal model to investigate the gel mechanics emerging in the critical range of length-scales from several tens to hundreds of nanometers. We show that the size polydispersity of the hydrates and size-dependent effective interactions can explain the mechanical heterogeneities detected in nano-indentation experiments. We also show how these features control the arising of irreversible structural rearrangements under deformation, which are good candidates as nano-scale mechanisms underlying mechanical aging and slow structural relaxation in the gels.

Graphical abstract: Nano-scale mechanics of colloidal C–S–H gels
VL - 10 IS - 3 ER -