电站特殊建筑外立面裂缝修补改性EP复材及性能测试

Repair and detection test of cracks in the coating layer of the facade of large-scale substation buildings

针对传统的环氧树脂(EP)在实用中存在耐热性差、黏度偏大的弊病,尝试利用聚氨酯对EP进行改性,探究了不同改性条件下EP修复材料的性能。试验结果表明,向EP中掺入适量的PPG、P-M能够有效拉低改性EP的黏度,即掺入20%的PPG,改性EP黏度降低为1021 MPa·s,掺入30%的PPG,改性EP黏度为1034 MPa·s;向EP中掺入少量PUP即可大幅提高改性EP黏度,即掺入30%的PUP,改性EP黏度激增至43274 MPa·s。在掺入PPG、P-M或PUP后,改性EP的断裂伸长率均有所升高以及拉伸强度均有所降低。试验采用抗折比值来表征不同修补材料对于混凝土裂缝的修补性能,证实了掺入25%的P-M时的抗折比值为1.96,高于未改性EP的1.51,这说明改性EP有效增强了混凝土的抗折性能。

In view of the poor heat resistance and high viscosity of traditional epoxy resin(EP)in practice,the polyurethane was tried to modify EP,and the properties of EP repair materials under different modification conditions were explored.The test results showed that the viscosity of modified EP effectively reduced by adding an appropriate amount of PPG and P-M into EP,that was,the viscosity of modified EP reduced to 1021 MPa·s by adding 20%PPG,and the viscosity of modified EP was 1034 MPa·s when mixed with 30%PPG.The viscosity of modified EP greatly increased by adding a small amount of PUP to EP,that was,the viscosity of modified EP increased to 43274 MPa·s by adding 30%PUP.After adding PPG,P-M or PUP,the elongation at break and tensile strength of the modified EP increased.The flexural resistance of different repair materials for concrete cracks was characterized,and it was confirmed that the flexural resistance value of 25%P-M was 1.96,which was higher than that of unmodified EP(1.51),which indicated that the modified EP effectively enhanced the flexural performance of concrete.