混凝土锈胀开裂寿命预测模型及其应用研究

Rebar corrosion expansion cover cracking service life forecasting model and it's application research

采用圆孔扩张理论对混凝土钢筋锈胀过程进行分析,推导了不同钢筋锈胀量对应的塑性区边界混凝土应力及塑性区半径计算公式,在此基础上建立了混凝土锈胀开裂寿命准则及寿命预测模型。锈胀开裂寿命模型分析表明,预测寿命值与钢筋相对保护层厚度m和混凝土等级有直接关系。随着相对厚度m增加,锈胀开裂预测寿命值增加,并且前期增加较快,后期增加较缓慢。混凝土强度等级对预测寿命值影响显著,随混凝土强度增大,混凝土锈胀开裂寿命增大。工程应用表明,该模型预测寿命可为工程的中度维护提供参考。

The rebar corrosion expansion process in reinforced concrete was analyzed by the rehar corrosion expansion model based on cylindrical cavity expansion theory, and the plastic zone radius and pressing stress equations for the different rebar corrosion ratio were deduced respectively. Based on cylindrical cavity expansion theory, the limit service life rule of rebar corrosion expansion cover cracking and reinforced concrete service life forecasting model were set up. This reinforced concrete service life forecasting model showed that the service life t was directly relative to the concrete strength grade, relative covering depth m and rust expansion rate n. Analysis of this forecasting model showed the service life of cover cracking increased quickly as the relative coverapplication of this reinforced concrete service life forecasting model showed the forecasted life could be provided as partial maintaining beginning time.