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养护条件对胶结充填体早期力学性能及微观结构的影响机制
Effect of Curing Conditions on the Early Mechanical Properties and Microstructure of Cemented Backfill
【摘要】 为揭示不同矿山充填环境下胶结体力学性能的影响机制及微观结构演化规律,研究采用X射线衍射分析(XRD)、傅里叶红外光谱分析(FT-IR)、热重-差示扫描量热分析(TG-DSC)和扫描电子显微镜分析(SEM)等检测方法,分别对恒温恒湿标养(SC)、套袋密封标养(BSC)、不拆模标养(DDSC)、35℃水浴湿养(WBC)、自然养护(NC)5种养护条件下,水化产物的物相组成、结构特征、水化热机理、微观形貌进行阐述。结果表明:不同养护条件下,水化产物均以钙矾石和C-S-H凝胶为主,产物组成无较大差异,但微观结构孔径分布及致密程度不同。DDSC养护条件下,胶结体内部水分不易散失而形成结合水膜,阻碍了水化反应离子交换进程,不利于胶结体强度的发展。相较于DDSC,在WBC养护条件下,升高温度增加了胶凝材料水化活性,矿渣玻璃体解聚、溶解速度加快,早期水化产物相互交织形成致密的网络结构,使得浆体结构密实度增加,为胶凝体系提供了强度支撑。
【Abstract】 To reveal the cementation strength performance under different mine filling environment mechanism and the influence of microstructure evolution,the X-ray diffraction analysis(XRD),Fourier Transform infrared spectroscopy(FT-IR),thermo gravimetric(TG)-differential scanning calorimetry analysis(TG-DSC)and scanning electron microscope(SEM)analysis detection method were used in the study,to describe the phase composition,structural characteristics,hydration heat mechanism and micromorphology of the hydration products under the different constant temperature and humidity keep(SC),seal the logo(BSC),not dismantle the 35 ℃ water bath(DDSC),wet pet(WBC),natural curing(NC)5 kinds of curing conditions.The results showed that under different curing conditions,the hydration products were mainly ettringite and C-S-H gel,and there was no significant difference in the composition of the products,but the pore size distribution and density degree of the microstructure were different.Under DDSC curing condition,the water inside the binder is not easy to be dissipated and the bonded water film is formed,which hinders the hydration reaction ion exchange process and is not conducive to the development of the strength of the binder.Compared with DDSC,under WBC curing condition,temperature increase increases hydration activity of cementitious materials,slag vitreous depolymerization and dissolution speed are accelerated,and early hydration products are interwoven to form a dense network structure,which increases the density of slurry structure and provides strength support for the cementitious system.
【Key words】 blast furnace slag; curing condition; mechanical properties; hydration products; microstructure;
- 【文献出处】 有色金属工程 ,Nonferrous Metals Engineering , 编辑部邮箱 ,2021年08期
- 【分类号】TD803;X751
- 【被引频次】6
- 【下载频次】208