The amount of inert quartz tailing used in concrete construction is limited due to the low strength development of cementitious materials that may be caused by the quartz tailing. We manage to increase the strength of...The amount of inert quartz tailing used in concrete construction is limited due to the low strength development of cementitious materials that may be caused by the quartz tailing. We manage to increase the strength of blended cement by modifying quartz tailing through solid-phase reaction of quartz tailing with carbide slag at high temperature. The mineral composition and morphology of the modified quartz tailing were examined by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The mechanical properties and microstructure of blended cement mortars containing modified quartz tailing were investigated. Results showed that the strengths of blended cement mortars containing modified quartz tailing were close to those of the corresponding blended cement mortars containing quartz tailing at early age of 3 d, but increased significantly to be similar to that of plain Portland cement mortars at late ages of 90 d. This is attributed to the microstructure densification and the enhancement of interface between quartz tailing and cement paste due to the hydration of b-C_2 S surface layer on modified quartz tailing.展开更多
基金Funded by the Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT)(No.IRT1146)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)+4 种基金Scientific Research Foundation of Education Department of Anhui Province-(No.KJ2013A257)the State Key Laboratory of MaterialsOriented Chemical Engineering(No.KL12-12)National Natural Science Foundation of China(Nos.51608004,51578004)Opening Foundation of State Key Laboratory of High Performance Civil Engineering Materials(No.2014CEM010)Natural Science Foundation of the Anhui Higher Education Institution(No.KJ2016A818)
文摘The amount of inert quartz tailing used in concrete construction is limited due to the low strength development of cementitious materials that may be caused by the quartz tailing. We manage to increase the strength of blended cement by modifying quartz tailing through solid-phase reaction of quartz tailing with carbide slag at high temperature. The mineral composition and morphology of the modified quartz tailing were examined by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The mechanical properties and microstructure of blended cement mortars containing modified quartz tailing were investigated. Results showed that the strengths of blended cement mortars containing modified quartz tailing were close to those of the corresponding blended cement mortars containing quartz tailing at early age of 3 d, but increased significantly to be similar to that of plain Portland cement mortars at late ages of 90 d. This is attributed to the microstructure densification and the enhancement of interface between quartz tailing and cement paste due to the hydration of b-C_2 S surface layer on modified quartz tailing.
