Based on the high sulfur content in titanium gypsum,the concept of the calcium-silicon-sulfur(Ca/Si/S)ratio was proposed.The Ca/Si/S ratio of concrete was adjusted by changing the titanium gypsum,fly ash,and cement co...Based on the high sulfur content in titanium gypsum,the concept of the calcium-silicon-sulfur(Ca/Si/S)ratio was proposed.The Ca/Si/S ratio of concrete was adjusted by changing the titanium gypsum,fly ash,and cement con-tent.The effects of different Ca/Si/S ratios on the mechanical properties,hydration products,and concrete micro-structure were investigated by nuclear magnetic resonance,uniaxial compression,and scanning electron microscopy.The result shows:(1)The compressive strength of concrete mixed with titanium gypsum increases first and then decreases with the Ca/Si/S ratio decrease.When the Ca/Si/S ratio is 1:0.85:0.10,the strength reaches the peak and is lower than the blank group.(2)The microstructure indicates the addition of titanium gypsum can effectively stimulate the activity of fly ash.Still,too much or too little titanium gypsum will hamper concrete strength development.(3)Titanium gypsum concrete’s nuclear magnetic resonance T2 spectrum has two characteristic peaks.With the Ca/Si/S ratio decreasing,the micropores in the concrete expand towards the macropores.The compressive strength is negatively correlated with the proportion of macropores and is positively correlated with the proportion of no-capillary pores.展开更多
基金National Natural Science Foundation of China(5210090341)Natural Science Foundation of Henan Province(202300410270)Fund of Innovative Education Program for Graduate Students at North China University of Water Resources and Electric Power,China(Grading No.YK-2021-39).
文摘Based on the high sulfur content in titanium gypsum,the concept of the calcium-silicon-sulfur(Ca/Si/S)ratio was proposed.The Ca/Si/S ratio of concrete was adjusted by changing the titanium gypsum,fly ash,and cement con-tent.The effects of different Ca/Si/S ratios on the mechanical properties,hydration products,and concrete micro-structure were investigated by nuclear magnetic resonance,uniaxial compression,and scanning electron microscopy.The result shows:(1)The compressive strength of concrete mixed with titanium gypsum increases first and then decreases with the Ca/Si/S ratio decrease.When the Ca/Si/S ratio is 1:0.85:0.10,the strength reaches the peak and is lower than the blank group.(2)The microstructure indicates the addition of titanium gypsum can effectively stimulate the activity of fly ash.Still,too much or too little titanium gypsum will hamper concrete strength development.(3)Titanium gypsum concrete’s nuclear magnetic resonance T2 spectrum has two characteristic peaks.With the Ca/Si/S ratio decreasing,the micropores in the concrete expand towards the macropores.The compressive strength is negatively correlated with the proportion of macropores and is positively correlated with the proportion of no-capillary pores.
