Microscopic reinforcement for cement based composite materials

Restriction of propagation and coalescence of cracks at microscopic level is one of the most effective means to achieve high properties of cement based composite. In order to improve the properties of cement based composite microcosmically, calcium carbonate whisker was introduced as a kind of microreinforcer. The effects of whisker on macro and micromechanical properties, fracture morphology, microstructures, and crack resistance of the composite with different water to binder ratios, as well as the reinforcing mechanisms were studied. The results indicated that whiskers are effective in delaying the formation and propagation of microcracks. The micromechanical mechanism is relative to the bond properties between whiskers and cement matrix. An appropriate interfacial bond strength is advantageous to optimize the reinforcing effect of whisker in cement based composite.

► Cement based materials were reinforced at microscopic level by incorporating calcium carbonate whisker.
► The effects on microcracks caused by whisker loading were discussed.
► The interfacial bond properties between whisker and cement matrix were analyzed.
► Strengthening and toughening mechanisms were given and analyzed in detail.