A new test method to study the influence of pore pressure on fracture behaviour of concrete during heating

作者：Felicetti Roberto^*; Lo Monte Francesco; Pimienta Pierre

来源：Cement and Concrete Research, 2017, 94: 13-23.

DOI：10.1016/j.cemconres.2017.01.002

• High temperature
• Explosive spalling
• Tensile strength
• Thermal stress
• Pore pressure

Fracture behaviour of concrete at high temperature is one of the factors governing explosive spalling, namely the expulsion of chunks due to both pressure build-up in the pores and stress induced by thermal gradients and external loads. In this context, a special experimental setup has been developed aimed at performing simple indirect-tension tests under different levels of sustained pore pressure. A cubic specimen is heated on two opposite faces, whereas the lateral sides are sealed and thermally insulated, so as to instate a mono-dimensional thermohygral transient field. In the splitting test, fracture develops along the symmetry plane, where both temperature and pressure are monitored by means of a customized probe. The results show that pore pressure has a significant influence on the mechanical response of heated concrete, though the concurrent contribution of external load and thermal strain is required for triggering explosive spalling.

• 出版日期2017-4