Chen Xuemei, Li Jun, Lu Zhongyuan, Niu Yunhui, Jiang Jun, Xu Yigang, Zhong Wen
State Key Laboratory of Environment-Friendly Energy Materials, School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China.
Jiahua Special Cement Co., Ltd., No. Ma'anshan Jiufeng Rd., Shizhong District, Leshan 614003, China.
Materials (Basel). 2022 Jun 20;15(12):4344. doi: 10.3390/ma15124344.
Brownmillerite-belite-sulfoaluminate clinker with different contents of brownmillerite were designed and successfully prepared by using limestone (LS), aluminum tailings (AT), aluminum mine (AM), and anhydrite (AH) calcined at 1330 °C for 30 min. Then, three kinds of brownmillerite-belite-sulfoaluminate cement (BBSC) were obtained by grinding mixtures of the clinker and AH. Hydration and mechanical performances of the prepared BBSC were thus intensively studied. The increase in brownmillerite in BBSC decreased the hydration exothermic rate and delayed the renewed rapid formation of AFt at early hydration stages. However, the formation of CAS·8HO would be promoted, where the higher the brownmillerite content in BBSC, the earlier the CAS·8HO formed. The increase in brownmillerite might change the morphologies of the formed AFt, grass-shaped AFt enriched in iron would be the main hydration products in BBSC with a higher content of brownmillerite. The increase in brownmillerite content contributed to the stability improvement in flexural strength and the stable growth in the compressive strength of BBSC. The appropriate content of brownmillerite (20 wt%) can balance the whole hydration reaction process, which was conducive to the development of BBSC mechanical strength, the decrease in the hydration heat release, and the volume stability of hardened pastes.
采用石灰石（LS）、铝尾矿（AT）、铝土矿（AM）和硬石膏（AH）在1330℃下煅烧30min，设计并成功制备了具有不同贝利特含量的钙钛矿-贝利特-硫铝酸盐熟料。然后，通过粉磨熟料与硬石膏的混合物，得到了三种钙钛矿-贝利特-硫铝酸盐水泥（BBSC）。对制备的BBSC的水化和力学性能进行了深入研究。BBSC中贝利特含量的增加降低了水化放热速率，并在水化早期延缓了AFt的再次快速形成。然而，会促进CAS·8H₂O的形成，BBSC中贝利特含量越高，CAS·8H₂O形成越早。贝利特含量的增加可能会改变所形成AFt的形貌，富含铁的草状AFt将是贝利特含量较高的BBSC中的主要水化产物。贝利特含量的增加有助于提高BBSC抗折强度的稳定性和抗压强度的稳定增长。适量的贝利特含量（20wt%）可以平衡整个水化反应过程，有利于BBSC力学强度的发展、水化热释放的降低以及硬化浆体的体积稳定性。
