海水-冻融共同作用下透水混凝土性能损伤及寿命预测OA北大核心CSTPCD

In order to solve the problem that pervious concrete used in northern coastal cities is susceptible to seawater-freeze-thaw co-action in winter,orthogonal tests were used to investigate the effects of slag(GBFS)substitution rate,hydroxypropylmethylcellulose(HPMC)admixture,and polypropylene imitation steel fiber(PPTF)admixture on macroscopic properties and microstructural changes of the pervious concrete blocks after seawater-freeze-thaw co-action for 25,50,and 75 times,and the NSGM(1,N)model was used to predict the relative dynamic elastic modulus of pervious concrete after seawater-freeze-thaw co-action.The NSGM(1,N)model was applied to predict the relative dynamic elastic modulus of permeable concrete after seawater-freeze-thaw.The results show that the permeable concrete has the best seawater-freeze-thaw resistance when the GBFS substitution ratess 20％and the HPMC and PPTF admixture are 0.15％and 0.5％,respectively;after seawater erosion,the generation of expansive substances accelerated the crack extension,and the supportive anchoring effect of PPTF suppressed the crack generation and extension.The test index a of the prediction accuracy of the NSGM(1,N)model is in[-3,2),and the average relative error is within the range of grade Ⅱ error.The NSGM(1,N)model can be used for long-term prediction of the relative dynamic elastic modulus.