【摘要】 采用碱性溶液静止浸泡和干湿循环两种方法对玻璃纤维增强塑料筋（GFRP）进行了不同时长的作用后，对筋体的力学性能进行表征，探究了其力学性能的退化规律，利用GFRP耐久性寿命预测公式，拟合得到了直径20 mm的GFRP力学性能的退化模型，并使用该模型预测了GFRP长期拉伸性能的变化趋势。结果表明，随着碱液对GFRP作用时间的延长，GFRP的拉伸强度显著降低，试验期间拉伸强度的退化主要集中在前90 d；直径20 mm的GFRP的初期拉伸强度退化较直径为25 mm的GFRP快，但经过一段时间后退化反而更慢，应力-应变关系变化规律与之一致；筋体的长期耐碱性能具有尺寸效应，与碱溶液的作用方式有关。更多还原

【Abstract】 In this study,the mechanical properties of glass fiber reinforcement polymers bars(GFRP)were investigated after subjected to dry-wet cycles and static immersion of alkaline solution for different days,and the reduction law of mechanical properties was analyzed. Based on the life prediction formula of durability of GFRP,a strength reduction model for the GFRP with a diameter of 20 mm subjected to the alkaline solution was obtained through linear fitting,and the model was used to predict the variation trend of long-term tensile properties of GFRP. The results indicated that the tensile strength of GFRP decreased significantly with an increase in the duration time of dry-wet cycles in the alkaline solution. The strength reduction mainly occurred in the first 90 days,and the GFRP with a diameter of 20 mm showed a faster initial strength reduction than that with a diameter of 25 mm. After a certain period,the reduction became slower,and however the stress-strain relationship was almost same. There was a size effect on the long-term alkali resistance of GFRP,being associated with the action mode of the alkaline solution.更多还原