中文摘要：

为了进一步研究约束混凝土和无约束混凝土的抗冻性能差异，以约束混凝土模型为参照，制作相同配合比的素混凝土立方体块并在相同条件下进行0、20、40、60、100、120次的冻融腐蚀试验。主要分析冻融腐蚀下素混凝土试块抗压强度，质量损失以及吸水率等性能随冻融次数的变化规律，并建立素混凝土抗压强度和质量损失冻融损伤预测模型。试验结果表明：随冻融循环次数增加，素混凝土的抗压强度呈抛物线下降，干燥质量和饱水质量呈线性下降，而吸水率则呈双折线下降。从材料层次方面，粉煤灰对混凝土抗压强度损失，质量损失率和吸水率影响较大，而水灰比对以上指标影响较小。掺15%粉煤灰的抗压强度损失比不掺粉煤灰的混凝土大约20%~30%；质量损失率比不掺粉煤灰的大5%~6%，粉煤灰不利于抗冻性能。相同粉煤灰含量，低水灰比抗压强度损失，质量损失率和吸水率变化比高水灰比小，使用粉煤灰混凝土时易降低水灰比。

英文摘要：

In order to further study the antifreeze performance difference of confined concrete and plain concrete,in confined concrete model for reference,making the same ratio of plain concrete cubic block and under the same conditions were also tested under freeze-thaw cycle of different numbers as 0,20,40,60,100 and 120 times,As the second part,mainly analyzed the compressive strength of plain concrete under freeze-thaw test,mass loss of samples and water absorption performance changing with the number of freezing and thawing,and establish the freeze-thaw damage prediction model of concrete compressive strength and mass loss ratio.Experiment showed that with the increase of freeze-thaw cycles,the compressive strength of plain concrete decreased parabola,drying quality and full water mass linearly decreased,while water absorption decreased by double line.From the aspects of material level,fly ash had a greater influence on the loss of concrete compressive strength,mass loss rate and water absorption,while water cement ratio had little influence on the above indicators.The loss of compressive strength of mixing 15%fly ash concrete was about 20%to 30%higher than mixing no fly ash concrete;Mass loss rate was about 5%to 6%larger than not mixing fly ash ,fly ash is not conducive to the antifreeze performance of concrete.As the same fly ash,the loss of compressive strength,mass and bibulous rate in low water-cement ratio concrete changed lager than high water cement ratio.When using fly ash concrete,it is easy to reduce the water cement ratio.