Quantitative Evaluation of Carbon Fiber Dispersion in Amorphous Calcium Silicate Hydrate-Based Contact-Hardening Composites

Carbon fiber dispersion has a substantial influence on the properties of amorphous calcium silicate hydrate-based contact-hardening composites. In this study, a mixture of carbon fiber and calcium silicate hydrate powder was compressed into solid composites at 40 MPa for one minute. The mechanical properties and electrical resistivity of the solid materials were measured, and the dispersion of carbon fibers was quantitatively evaluated by digital image processing technology. The Taipalu model was used to build the correlation between the electrical resistivity of the composites and the carbon fiber dispersion. The results of the electrical resistivity showed that the down threshold of carbon fiber content in the contact-hardening composites was 1.0 wt.% and the electrical resistivity was 30,000 Ω·cm. As the fiber content increased to 2.0 wt.%, the electrical resistivity dropped to 2550 Ω·cm, which was attributed to the increase in fiber dispersion uniformity in the solid composites, and the value of the fiber distribution coefficient reached a maximum value of 0.743. A subsequent decrease in the uniformity of the fiber dispersion was observed at a high fiber content. In addition, the carbon fiber content showed a slight influence on the fiber orientation in the contact-hardening composites.

Forecasting Durability of Construction Composites on the Basis of Liquid Rubber

Initial theoretical propositions based on S.N. Zhurkov’s concept about termo-fluctuation approach to mechanics of destruction and solid bodies straining is formulated, formulas of dependence limits functionality of solid composites are described in the article. Physical constants of six rubber polymeric concrete composition are experimentally detected, the results of experiments are analyzed and described. The prediction and enhancement problem of working capacity for the polymeric construction materials come to detection of relationship between power, temperature and temporal limits of the material use. The optimal composition of rubber polymeric concrete from the power, temperature and temporal durability point of view is detected from the experiments results.