Halloysite is an affordable natural mineral clay with a nanotubular structure and surface reactivity, giving it strong industrialization potential. This study investigated how the calcination temperature (0°C-850 °C) affected the properties of halloysite and geopolymers derived from calcined halloysite, then as a modified material, the performances of a slag/fly-ash geopolymer with halloysite calcined at different temperatures were compared. Finally, the effects of halloysite curing temperature (20°C-80 °C) and mass content (0.25%–1.5 %) on the mechanical properties and microstructure of the slag/fly-ash geopolymer were studied. The results show that the calcination temperature of 750 °C was optimal for stimulating the halloysite's activity, leading to the highest compressive strength of 42.7 MPa of the halloysite-based geopolymer. Uncalcined halloysite was the most suitable reinforcement for slag/fly-ash geopolymer because it retains relatively intact tubular structure, and its chemical bonding at the interface with geopolymers ensured good reinforcing properties. The bridging effect derived from tubular structure of halloysite led to a more noticeable enhancement of flexural strength. To prevent agglomeration from too much tubular halloysite, 1.0 % content was found to be optimal. The compressive and flexural strengths reached 62.5 MPa and 3.83 MPa, respectively, which were 9.84 % and 35.8 % higher than that without halloysite. Furthermore, with increasing curing temperature, the strength of the halloysite-modified geopolymer reached its peak at 60 °C. For 1.0 % halloysite modified geopolymer, the compressive strength was 87.0 MPa and the flexural strength was 4.56 MPa, respectively, which were 39.2 % and 19.1 % higher than that at the curing temperature of 20 °C.

中文翻译：

---

埃洛石基和埃洛石改性矿渣/粉煤灰基地聚合物的力学性能


埃洛石是一种价格实惠的天然矿物粘土，具有纳米管状结构和表面反应性，具有强大的工业化潜力。本研究研究了煅烧温度 （0°C-850 °C） 如何影响埃洛石和由煅烧埃洛石衍生的地聚合物的性能，然后作为改性材料，比较了不同温度下煅烧埃洛石的矿渣/粉煤灰地质聚合物的性能。最后，研究了埃洛石固化温度 （20°C-80 °C） 和质量含量 （0.25%–1.5 %） 对矿渣/粉煤灰地质聚合物力学性能和微观结构的影响。结果表明，750 °C的煅烧温度是刺激埃洛石活性的最佳温度，导致埃洛石基地聚合物的抗压强度最高，为42.7 MPa。未煅烧埃洛石是矿渣/粉煤灰地聚合物最合适的增强材料，因为它保留了相对完整的管状结构，并且在与地聚合物界面处的化学键确保了良好的增强性能。埃洛石管状结构衍生的桥接效应导致弯曲强度的增强更加明显。为了防止过多的管状埃洛石团聚，发现 1.0% 的含量是最佳的。其抗压强度和抗折强度分别达到 62.5 MPa 和 3.83 MPa，比无埃洛石时分别提高了 9.84 % 和 35.8 %。此外，随着固化温度的升高，埃洛石改性地聚合物的强度在 60 °C 时达到峰值。 1.0 %埃洛石改性地聚合物的抗压强度为87.0 MPa，弯曲强度为4.56 MPa，比20 °C固化温度下分别提高了39.2 %和19.1 %。