偏高岭土混凝土抗冻性能及寿命预测

Frost Resistance and Life Prediction of Metakaolin Concrete

通过开展偏高岭土混凝土的力学性能及抗冻性能的试验研究,分析了不同偏高岭土掺量下试件的抗压强度及抗冻性的各项指标的变化规律,并针对内蒙古地区,对不同掺量的偏高岭土混凝土进行了抗冻耐久性寿命预测。试验结果表明,偏高岭土混凝土的抗压强度随着偏高岭土掺量的增加逐渐增大;随着偏高岭土掺量的增加,试件的抗剥落情况得到明显改善,抗冻性逐渐增大;相对抗压强度随着损伤度的增加逐渐降低,一次函数和指数函数较好的拟合了二者之间的关系。以相对动弹模量为变量建立的冻融损伤模型可靠性较高;偏高岭土掺量越高,混凝土的抗冻耐久性预测寿命越长,掺量为15%的偏高岭土混凝土可以考虑在寒冷地区实际工程中应用。

Through the experimental study on the mechanical properties and frost resistance of metakaolin concrete,the changing rules of compressive strength and frost resistance of specimens with different metakaolin content were analyzed,and aiming at Inner Mongolia,the anti-freezing durability life of metakaolin concrete with different content was predicted.The test results show that the compressive strength of metakaolin concrete increases with the increase of metakaolin content.With the increase of metakaolin content,the spalling resistance of specimens is obviously improved,and the frost resistance increases gradually.The relative compressive strength decreases with the increase of damage degree,and the relationship between them is well fitted by first-order function and exponential function.The freeze-thaw damage model established with the relative dynamic modulus of elasticity as a variable is more reliable;the higher the content of metakaolin is,the longer the predicted life of frost durability of concrete is.The metakaolin concrete with 15%content can be considered to be used in practical engineering in cold areas.