Suggested continued heat-treatment method for investigating static and dynamic mechanical properties of cement-based materials

• To investigate mechanical properties of mortar subjected to continued heat treatment.
• To simulate a more accurate predictive formula using a continuous equation.
• To find critical damaged points using a more accurate predictive formula.
• To investigate the feature width of process zones using acoustic emissions.

Thermo-induced damage affects the structural and material safety of civil engineering structures; the damage can induce direct or indirect extensive structural collapse.An innovative continued heat-treatment method to obtain several specimen pieces in a single cylinder of mortar was described in this paper; the intended purpose of the method was to predict the effects of heat treatment on the static and dynamic mechanical properties and characteristic width of process zones.All of the results can be regressed by a continuous equation; therefore, the regression equations obtained from the results of continued heat-damaged specimen pieces represented more accurate prediction equations. Moreover, using the Log–Log method resulted in a critical damage temperature of approximately 547.5 °C. For a temperature range between room temperature and approximately 547.5 °C; the variation of all of the mechanical properties decreased by approximately 10–11% per 100 °C, but they decreased by approximately 29–31% per 100 °C between 547.5 °C and the highest temperature used in the tests. Finally, the fracture characteristics and the width of the process zones could be investigated using the acoustic emission technique; the width was wider at lower temperatures than at higher temperatures.