The aim of this study is to enhance the value and utilization of red mud generated in the Bayer process by preparing composite cement mortars.The effects of two different types of Bayer red mud with varying physical a...The aim of this study is to enhance the value and utilization of red mud generated in the Bayer process by preparing composite cement mortars.The effects of two different types of Bayer red mud with varying physical and chemical characteristics on the fluidity,mechanical strength,mineral composition,and microstructure of the composite cement mortar were systematically evaluated.The results showed that the optimal addition of red mud A was 10 wt%,while it was 20 wt% for red mud B.The mechanical properties of the composite cement mortar met the standards for P·O42.5 cement.Furthermore,the composite mortar with the addition of red mud B showed higher flexural and compressive strengths compared to the composite mortar with red mud A.This improvement is attributed to the smaller particle size of red mud B,which filled the micro-pores and increased the compactness of the cement stone,as well as its higher content of Na_(2)O,K_(2)O,and other free alkalis,which resulted in more obvious alkali activation,accelerating the hydration of the active minerals in the slurry.展开更多
Traditional cement-based materials are being gradually replaced by nanomodified cement-based materials because the traditional materials cannot meet the production needs of modern society.Nano-iron boride(nano-FeB)is ...Traditional cement-based materials are being gradually replaced by nanomodified cement-based materials because the traditional materials cannot meet the production needs of modern society.Nano-iron boride(nano-FeB)is a high-performance nanomaterial prepared from waste iron powder during construction.Its one-dimensional structure is similar to that of carbon nanotubes,which makes it a potential candidate for nano-reinforcement materials.In this paper,the effects of different contents of recycled nano-FeB(0%,0.05%,0.075%,and 0.1 wt.%,based on cement weight)on the mechanical properties and electrical conductivity of cement mortar were studied.The results showed that the mechanical properties of the composite cement mortar were improved with the addition of nano-FeB.When the content of nano-FeB was 0.075%,the 28 d compressive strength and flexural strength of the composite cement mortar increased by 60.2%and 42.1%,respectively.In addition,a 0.075%nano-FeB content favorably improved the conductivity of cement mortar.Compared with that of the control group,the volume resistivity of the composite cement mortar decreased by one order of magnitude.展开更多
基金the Guangxi Science and Technology Program(Guike AD21220052,AD22035126 and AB22035064)National Natural Science Foundation of China(52062009)Guangxi Key Laboratory of New Energy and Building Energy Saving(Guikeneng 22-J-21-19).
文摘The aim of this study is to enhance the value and utilization of red mud generated in the Bayer process by preparing composite cement mortars.The effects of two different types of Bayer red mud with varying physical and chemical characteristics on the fluidity,mechanical strength,mineral composition,and microstructure of the composite cement mortar were systematically evaluated.The results showed that the optimal addition of red mud A was 10 wt%,while it was 20 wt% for red mud B.The mechanical properties of the composite cement mortar met the standards for P·O42.5 cement.Furthermore,the composite mortar with the addition of red mud B showed higher flexural and compressive strengths compared to the composite mortar with red mud A.This improvement is attributed to the smaller particle size of red mud B,which filled the micro-pores and increased the compactness of the cement stone,as well as its higher content of Na_(2)O,K_(2)O,and other free alkalis,which resulted in more obvious alkali activation,accelerating the hydration of the active minerals in the slurry.
基金Financial support from the National Natural Science Foundation of China under the grants of 51578477 and 51708403the Key Research and Development Project of Hebei Province under the grant of 19211505D,and the China Postdoctoral Science Foundation under the grants of 2018T110200 and 2018M640236 is gratefully acknowledged.
文摘Traditional cement-based materials are being gradually replaced by nanomodified cement-based materials because the traditional materials cannot meet the production needs of modern society.Nano-iron boride(nano-FeB)is a high-performance nanomaterial prepared from waste iron powder during construction.Its one-dimensional structure is similar to that of carbon nanotubes,which makes it a potential candidate for nano-reinforcement materials.In this paper,the effects of different contents of recycled nano-FeB(0%,0.05%,0.075%,and 0.1 wt.%,based on cement weight)on the mechanical properties and electrical conductivity of cement mortar were studied.The results showed that the mechanical properties of the composite cement mortar were improved with the addition of nano-FeB.When the content of nano-FeB was 0.075%,the 28 d compressive strength and flexural strength of the composite cement mortar increased by 60.2%and 42.1%,respectively.In addition,a 0.075%nano-FeB content favorably improved the conductivity of cement mortar.Compared with that of the control group,the volume resistivity of the composite cement mortar decreased by one order of magnitude.
