Cement,phosphorous slag(PS),and steel slag(SS)were used to prepare low-carbon cementitious materials,and triisopropanolamine(TIPA)was used to improve the mechanical properties by controlling the hydration process.The ...Cement,phosphorous slag(PS),and steel slag(SS)were used to prepare low-carbon cementitious materials,and triisopropanolamine(TIPA)was used to improve the mechanical properties by controlling the hydration process.The experimental results show that,by using 0.06%TIPA,the compressive strength of cement containing 60%PS or 60%SS could be enhanced by 12%or 18%at 28 d.The presence of TIPA significantly affected the hydration process of PS and SS in cement.In the early stage,TIPA accelerated the dissolution of Al in PS,and the formation of carboaluminate hydrate was facilitated,which could induce the hydration;TIPA promoted the dissolution of Fe in SS,and the formation of Fe-monocarbonate,which was precipitated on the surface of SS,resulting in the postponement of hydration,especially for the high SS content.In the later stage,under the continuous solubilization effect of TIPA,the hydration of PS and SS could refine the pore structure.It was noted that compared with portland cement,the carbon emissions of cement-PS-TIPA and cement-SS-TIPA was reduced by 52%and 49%,respectively.展开更多
Blended cement containing blast furnace slag (BFS) and phosphorous slag( PS) is a new kind of cement. The total content of blended materials could increase if two additives were used. Using the same admixtures , the p...Blended cement containing blast furnace slag (BFS) and phosphorous slag( PS) is a new kind of cement. The total content of blended materials could increase if two additives were used. Using the same admixtures , the properties of the blended cement with 70% additives could reach the standard of 525-grade slag cement according to GB. The strength of cement with 80% additives could reach the standard of 425-grade slag cement. The tests of strength, pore structure, hydration products, inhibiting alkali-aggregate reaction, resistance to sulfate corrosion of BFS-PSC were performed.展开更多
By means of hydration heat, XRD and SEM, effect of phosphorus and fluorine （P205 and F-） in phosphorous slag on hydration process of tricalcium silicate （C3S） and tricalcium aluminate （C3A） was explored. The res...By means of hydration heat, XRD and SEM, effect of phosphorus and fluorine （P205 and F-） in phosphorous slag on hydration process of tricalcium silicate （C3S） and tricalcium aluminate （C3A） was explored. The results indicated that the early hydration exothermic rate of C3S and C3A was obviously lowered by P205 and F- in phosphorous slag, the second peak occurring time of C3A was delayed by 0.9 h, the exothermal output of C3S was reduced by 25.04% and the time of accelerating stage was postponed by 0.86 h. The early hydration degree of C3S and C3A was also decreased. Due to the influence of P205 and F, more pores and thinner crystals can be observed in the microstructure of hardened paste and the chance of cracks was reduced.展开更多
基金Funded by the Key Public Welfare Special Project of Henan Province(No.201300311000)the Major Technical Innovation Project in Hubei Province of China(No.2020BED025)。
文摘Cement,phosphorous slag(PS),and steel slag(SS)were used to prepare low-carbon cementitious materials,and triisopropanolamine(TIPA)was used to improve the mechanical properties by controlling the hydration process.The experimental results show that,by using 0.06%TIPA,the compressive strength of cement containing 60%PS or 60%SS could be enhanced by 12%or 18%at 28 d.The presence of TIPA significantly affected the hydration process of PS and SS in cement.In the early stage,TIPA accelerated the dissolution of Al in PS,and the formation of carboaluminate hydrate was facilitated,which could induce the hydration;TIPA promoted the dissolution of Fe in SS,and the formation of Fe-monocarbonate,which was precipitated on the surface of SS,resulting in the postponement of hydration,especially for the high SS content.In the later stage,under the continuous solubilization effect of TIPA,the hydration of PS and SS could refine the pore structure.It was noted that compared with portland cement,the carbon emissions of cement-PS-TIPA and cement-SS-TIPA was reduced by 52%and 49%,respectively.
文摘Blended cement containing blast furnace slag (BFS) and phosphorous slag( PS) is a new kind of cement. The total content of blended materials could increase if two additives were used. Using the same admixtures , the properties of the blended cement with 70% additives could reach the standard of 525-grade slag cement according to GB. The strength of cement with 80% additives could reach the standard of 425-grade slag cement. The tests of strength, pore structure, hydration products, inhibiting alkali-aggregate reaction, resistance to sulfate corrosion of BFS-PSC were performed.
基金Funded by the National Natural Science Foundation of China (No.50802067)
文摘By means of hydration heat, XRD and SEM, effect of phosphorus and fluorine （P205 and F-） in phosphorous slag on hydration process of tricalcium silicate （C3S） and tricalcium aluminate （C3A） was explored. The results indicated that the early hydration exothermic rate of C3S and C3A was obviously lowered by P205 and F- in phosphorous slag, the second peak occurring time of C3A was delayed by 0.9 h, the exothermal output of C3S was reduced by 25.04% and the time of accelerating stage was postponed by 0.86 h. The early hydration degree of C3S and C3A was also decreased. Due to the influence of P205 and F, more pores and thinner crystals can be observed in the microstructure of hardened paste and the chance of cracks was reduced.
