Failure probability model and meso-degradation law of high performance cement-based composites in salt-frozen environment

Abstract

In order to investigate the damage characteristics and degradation law of high performance cement-based composites (HPCC) in salt-frozen environment, the effect of freeze-thaw cycles on the loss rate of relative dynamic modulus was analyzed, based on the theories of damage mechanics, fracture mechanics and fractal geometry, deriving an equation to determine the failure probability of HPCC in salt-frozen environment.The equation not only considers the effect of cycle number on freeze-thaw damage, but also introduces the fractal dimension of bubble distribution.The freeze-thaw cycles of HPCC in different test groups were carried out to verify the model, and the pore structure parameters of HPCC in different freeze-thaw cycles were tested to analyze its meso-degradation law, the models of bubble distance coefficient and average chord length are established, which can quantitatively characterize HPCC meso-scale degradation characteristics.The results showed that:the calculated results of the salt freezing failure probability model were in good agreement with the test results. The model can accurately describe the failure probability of HPCC with different freeze-thaw cycles.The meso-degradation rule indicates that with the increase of freeze-thaw cycles, the small holes and micro-cracks in the matrix transition to the big holes, the matrix structure changes from compact and hard to porous, and the frost resistance durability decreases significantly.The meso-structure degradation model can quantitatively calculate the characteristic values of bubble spacing coefficient and average chord length degradation of bubbles, and provide a non-destructive evaluation method for subsequent HPCC meso-structure degradation research.

Highlights

• Deriving an equation to determine the failure probability of HPCC in salt-frozen environment.

• The meso-degradation rule of HPCC was found that the transition from small holes and micro-cracks to big holes in the matrix.

• A relationship model for quantitative characterization of the eigenvalues of meso-structure degradation was established.

Keywords:

• Freeze-thaw cycle
• dynamic modulus
• fractal dimension
• pore structure
• degradation characteristic

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

The financial support provided by the Natural Science Foundation of China (51468049), Natural Science Foundation of Inner Mongolia Autonomous Region (2020LH05008), Science and Technology Plan Project Foundation of Inner Mongolia Autonomous Region (RZ2000000422-[2020]), and Heilongjiang Provincial Undergraduate Colleges and Universities Fundamental Scientific Research Special Fund Project (2020-KYYWF-0537) is gratefully acknowledged.