In order to explore the internal curing mechanism of sepiolite in cement-based materials,the effects of sepiolite on the water consumption of standard consistency,setting time,viscosity,strength,pore structure charact...In order to explore the internal curing mechanism of sepiolite in cement-based materials,the effects of sepiolite on the water consumption of standard consistency,setting time,viscosity,strength,pore structure characteristics,micro-hardness characteristics and two-dimensional surface characteristics of cement paste were studied,respectively.The experimental results show that the water consumption of standard consistency increases linearly with the increase of sepiolite content.The setting time and viscosity are also lengthened and increased with the addition of sepiolite,respectively.When the content of sepiolite exceeds 5%,the strength of the specimen increases significantly.The BET results show that the pore structure of the interfacial transition zone(ITZ)in hardened cement paste(HCP)with sepiolite is optimized after curing for28 d and its pore volume content with below 10 nm is decreased,especially for the specimen with a lower watercement ratio.The characteristics of microhardness and strength of specimens have the same law.Backscattered electron image(BSE-IA)shows that the ITZ of the specimen with sepiolite is denser and the unhydrated cement particles are less than the reference specimen.展开更多
A set of coupling experimental instrument was designed to study the transport properties of chloride ion in concrete under simultaneous coupling action of fatigue load and environmental factors. Firstly the water-satu...A set of coupling experimental instrument was designed to study the transport properties of chloride ion in concrete under simultaneous coupling action of fatigue load and environmental factors. Firstly the water-saturated performance of modem concrete was investigated, then diffusion performance of chloride ion under different stress levels and different temperature were studied respectively; meanwhile, the time- dependent behavior of the chloride ion diffusion in concrete was also researched. The results showed that the saturation degree of concrete can reach as high as 99%. Besides, diffusion coefficient of chloride ion increased with increasing of the stress level and temperature, and when the stress level and temperature are at 0.6 and 60 ℃ respectively, the diffusion coefficient is 6.3 ×10 -14 m2/s, moreover the diffusion coefficient of chloride ion in concrete decreased with time under the simultaneous coupling action of fatigue load and environment factors.展开更多
基金Funded by the Natural Science Foundation of China(No.51408380)the Science and Technology Plan of He Bei Province(No.E2021210033)the Scientific and Technological Development Funds of the Central Government Shall Guide Local(No.216Z3801G)。
文摘In order to explore the internal curing mechanism of sepiolite in cement-based materials,the effects of sepiolite on the water consumption of standard consistency,setting time,viscosity,strength,pore structure characteristics,micro-hardness characteristics and two-dimensional surface characteristics of cement paste were studied,respectively.The experimental results show that the water consumption of standard consistency increases linearly with the increase of sepiolite content.The setting time and viscosity are also lengthened and increased with the addition of sepiolite,respectively.When the content of sepiolite exceeds 5%,the strength of the specimen increases significantly.The BET results show that the pore structure of the interfacial transition zone(ITZ)in hardened cement paste(HCP)with sepiolite is optimized after curing for28 d and its pore volume content with below 10 nm is decreased,especially for the specimen with a lower watercement ratio.The characteristics of microhardness and strength of specimens have the same law.Backscattered electron image(BSE-IA)shows that the ITZ of the specimen with sepiolite is denser and the unhydrated cement particles are less than the reference specimen.
基金Supported by the Scientif ic Research Foundation of Graduation School of Southeast University(No.YBjj1129)the National Natural Science Foundation of China(No. 51078081)Ph D Programs Foundation of Ministry of Education of China(No. 200802861080)
文摘A set of coupling experimental instrument was designed to study the transport properties of chloride ion in concrete under simultaneous coupling action of fatigue load and environmental factors. Firstly the water-saturated performance of modem concrete was investigated, then diffusion performance of chloride ion under different stress levels and different temperature were studied respectively; meanwhile, the time- dependent behavior of the chloride ion diffusion in concrete was also researched. The results showed that the saturation degree of concrete can reach as high as 99%. Besides, diffusion coefficient of chloride ion increased with increasing of the stress level and temperature, and when the stress level and temperature are at 0.6 and 60 ℃ respectively, the diffusion coefficient is 6.3 ×10 -14 m2/s, moreover the diffusion coefficient of chloride ion in concrete decreased with time under the simultaneous coupling action of fatigue load and environment factors.
