玻璃钢复合材料在海洋环境下的抗冻耐久性能研究

Durability of GFRP Composites under Freeze-Thaw Cycling in Seawater Environment

采用1 000次冻融循环试验研究了189不饱和聚酯玻璃钢和MFE–2,MFE–711,MFE–W1环氧乙烯基酯玻璃钢在海水中的抗冻耐久性能。结果表明,1 000次冻融循环试验后,189不饱和聚酯玻璃钢和MFE–711环氧乙烯基酯玻璃钢的树脂基体在冻融循环产生的应力作用下发生开裂破坏,弯曲强度保留率降低至30%左右,渗入189不饱和聚酯玻璃钢和MFE–711环氧乙烯基酯玻璃钢包覆的混凝土试样表层的氯离子质量分数分别为0.08%和0.12%;MFE–2和MFE–W1环氧乙烯基酯玻璃钢在750次冻融循环后,弯曲强度保留率降至最低值65%,且不再随冻融循环次数增加而降低,1 000次冻融循环后,在MFE–2和MFE–W1环氧乙烯基酯玻璃钢包覆的混凝土试样表层未检测到氯离子渗入,它们的树脂基体在冻融循环产生的应力作用下未发生开裂破坏,具有较好的抗冻耐久性能。玻璃钢复合材料的冻融破坏是缓慢累积的过程,至少需要1 000次的冻融循环试验才能区分其抗冻耐久性能的优劣。

1 000 freeze-thaw cycles in seawater environment were conducted to evaluate the freeze-thaw resistance of four kinds glass fiber reinforced plastics（GFRP） composites. The results show that the bending strength retention rate of 189 GFRP and MFE–711 GFRP composites drops almost to 30%,while the bending strength retention rate of MFE–2 GFRP and MFE–W1 GFRP composites are both higher than 65%. The freeze-thaw resistance property of GFRP composites is greatly related with their maximum water absorption rate and mechanical property of their resin castings. There is Cl– detected in the surface concrete wrapped with 189 GFRP and MFE–711 GFRP composites after 1 000 cycles,the permeated mass fraction of Cl– is 0.08% and 0.12% respectively;while no Cl– being detected in the surface concrete wrapped with MFE–2 GFRP and MFE–W1 GFRP composites after 1 000 cycles. The freeze-thaw damage to GFRP composites is a process of slow and gradual accumulation. In order to evaluate the freeze-thaw resistance property of GFRP composites,1 000 freeze-thaw cycles at least,must be done.