This paper studied the effects of different retarders on the performance of the"one-step"alkali-activated composite cementitious material(ACCM)which is composed of ground granulated blast slag(GGBS)and fly a...This paper studied the effects of different retarders on the performance of the"one-step"alkali-activated composite cementitious material(ACCM)which is composed of ground granulated blast slag(GGBS)and fly ash(FA),and analyzed its mechanical properties,hydration mechanism,and retardation mechanism.The effects of retarders on the hydration products,mechanical properties,and hydration kinetics of ACCM were investigated using XRD,SEM,FTIR,EDS,and thermoactive microcalorimetry.The results showed that Na_(2)B_(4)O_(7)·10H_(2)O(B)delayed the exotherm during the alkali activation process and could effectively delay the setting time of ACCM,but the mechanical properties were slightly decreased.The setting time of ACCM increased with the increase in SG content,but the mechanical properties of ACCM decreased with the increase in SG content.C1_(2)H_(22)O_(11)(CHO)could effectively delay the hydration reaction of ACCM and weakly enhanced the compressive strength.H_(3)PO_(4)(HP)at a concentration of 0.05 mol/L had a certain effect on ACCM retardation,but HP at a concentration of 0.07 and 0.09 mol/L had an effect of promoting the setting and hardening time of ACCM.展开更多
China is setting to roll out more strict emissions rule of CHINA Ⅵ Emission Standard which poses huge challenge to automotive catalytic technology.Rare earth elements are the key compositions of the catalysts coating...China is setting to roll out more strict emissions rule of CHINA Ⅵ Emission Standard which poses huge challenge to automotive catalytic technology.Rare earth elements are the key compositions of the catalysts coating.To develop multiple-component rare earth materials is an important way to improve the performance of the catalyst.The study concluded that quaternary or quinary rare earth materials for CHINA Ⅵ Emission Standard,can improve substantially the oxygen storage capacity and high thermal stability of the catalyst,after the modification by Pr/NdAT elements.It improved the utilization efficiency of precious metal.展开更多
基金Funded by Key Laboratory for Comprehensive Energy Saving of Cold Regions Architecture of Ministry of Education(No.JLJZHDKF202204)。
文摘This paper studied the effects of different retarders on the performance of the"one-step"alkali-activated composite cementitious material(ACCM)which is composed of ground granulated blast slag(GGBS)and fly ash(FA),and analyzed its mechanical properties,hydration mechanism,and retardation mechanism.The effects of retarders on the hydration products,mechanical properties,and hydration kinetics of ACCM were investigated using XRD,SEM,FTIR,EDS,and thermoactive microcalorimetry.The results showed that Na_(2)B_(4)O_(7)·10H_(2)O(B)delayed the exotherm during the alkali activation process and could effectively delay the setting time of ACCM,but the mechanical properties were slightly decreased.The setting time of ACCM increased with the increase in SG content,but the mechanical properties of ACCM decreased with the increase in SG content.C1_(2)H_(22)O_(11)(CHO)could effectively delay the hydration reaction of ACCM and weakly enhanced the compressive strength.H_(3)PO_(4)(HP)at a concentration of 0.05 mol/L had a certain effect on ACCM retardation,but HP at a concentration of 0.07 and 0.09 mol/L had an effect of promoting the setting and hardening time of ACCM.
文摘China is setting to roll out more strict emissions rule of CHINA Ⅵ Emission Standard which poses huge challenge to automotive catalytic technology.Rare earth elements are the key compositions of the catalysts coating.To develop multiple-component rare earth materials is an important way to improve the performance of the catalyst.The study concluded that quaternary or quinary rare earth materials for CHINA Ⅵ Emission Standard,can improve substantially the oxygen storage capacity and high thermal stability of the catalyst,after the modification by Pr/NdAT elements.It improved the utilization efficiency of precious metal.
