Research Of Recycled Mortar On Mechanical Properties And Frost Resistance And Dry Shrinkage

With the rapid development of urbanization,the reconstruction of waste buildings that are not able to meet the requirements of earthquake resistance and applicability will produce a large number of construction waste company,which will not only occupy the land resources but also pollute the environment.The reuse of construction waste as a resource in actual projects is of great significance for save resources of building materials,protect and maintain ecological environment balance.Therefore,the single factor test was designed for the change of the replacement rate of recycled fine aggregate,the replacement rate of the wrap recycled fine aggregate,basalt fiber content and aspect ratio of basalt fiber.The workability,basic mechanics and frost resistance of M15 mortar with recycled fine aggregate before and after the treatment of cement wrapped was studied.In addition,after adding fiber to the recycled fine aggregate mortar,the basic mechanics and drying shrinkage of fiber recycled mortar were studied by changing content and aspect ratio of the basalt fiber.Through the experimental study,it is found that the recycled fine aggregate before and after the treatment of wrap has an obvious enhancement on the compressive and flexural strength of the mortar,and the addition of basalt fiber effectively improves the dry shrinkage of the recycled fine aggregate mortar.It provides theoretical support and scientific basis for the application of basalt fiber recycled fine aggregate mortar to practical engineering.The results of the study show that:(1)Compared with ordinary mortar,the water requirement of recycled fine aggregate mortar is much more than ordinary mortar,and the sinking degree is obviously lower than ordinary mortar,and the apparent density is lower than that of ordinary mortar.(2)In the range of recycled fine aggregate replacement rate selected in the test,the compressive strength of unwrapped and wrapped recycled mortar is the highest when the replacement rate of recycled fine aggregate is 80%,and the flexural strength of unwrapped and wrapped recycled mortar is the highest when the replacement rate of recycled fine aggregate is 70%.And the compressive strength of the wrapped recycled fine aggregate mortar is obviously higher than that of the unwrapped fine aggregate mortar,but the flexural strength is just the opposite.The frost resistance of the wrapped recycled fine aggregate mortar is getting better as the replacement rate of recycled fine aggregate increases.(3)The basalt fiber has an obvious enhancement for the 3d compressive and flexural strength of t recycled fine aggregate mortar.The compressive strength and the flexural strength reach the maximum when the content of basalt fiber is 0.05%.From the whole,basalt fiber has the inhibited effect for the 28d compressive and flexural strength of the recycled fine aggregate mortar.The flexural strength reaches the maximum when the content of basalt fiber is 0.05%.In the range of the selected basalt fiber content,with the increase of basalt fiber content,the dry shrinkage of the recycled mortar that inhibits is more obvious.(4)The change of the aspect ratio of basalt fiber has nearly no effect on the compressive strength of the basalt fiber recycled fine aggregate mortar.However,in the range of the aspect ratio of the selected fiber,with the increase of the aspect ratio of the fiber,the flexural strength increases but the increase is small,and the drying shrinkage of the basalt fiber recycled fine aggregate mortar is obviously improved.