贝利特—硫铝酸钡钙水泥熟料中硅酸盐相微结构调控和性能研究

发布时间：2018-05-23 20:37

  本文选题：微量组分 + 贝利特-硫铝酸钡钙水泥　； 参考：《济南大学》2014年硕士论文

【摘要】：传统硅酸盐水泥具有能耗高、消耗优质石灰石资源、CO2排放量大等缺点，而且其体积稳定性和耐久性还需进一步提高。贝利特-硫铝酸钡钙水泥（BSAC）是环境友好、长期力学性优异的水泥体系之一，但是该水泥早期力学性能尚不足，本文旨在引入微量组分和改善煅烧制度，调节熟料中的硅酸盐相—贝利特和阿利特的微结构，通过稳定其高温高活性晶型或使晶格产生畸变，进一步提高硅酸盐相的反应活性，以达到提高水泥早期强度的目的。主要研究结论如下： （1）对于C2S单矿体系，在微量组分作用下C2S晶型主要为β-C2S与γ-C2S，稳定β-C2S的大小顺序为：SO3SrONa2OK2OBaO无掺试样MgO；BaO对稳定αL’-C2S有一定作用，而Na2O与K2O稳定作用较弱；复合掺杂能够进一步降低试样粉化率并稳定C2S高温晶型；对于C3S单矿体系，在微量组分作用下C3S晶型主要为T型和M型，其中MgO对稳定M3-C3S作用明显，甚至可以稳定R型C3S；掺杂1.5%-3%BaO对稳定M型C3S有明显作用；K2O存在时，C3S主要晶型为T型；掺杂0.5%-1.5%Na2O可以使C3S稳定为M型；掺杂1%SrO可以使C3S由T型向M型转变；在中间相和微量组分协同作用的熟料中，贝利特主要为α-C2S，当C3A/C4AF=2:5时，阿利特晶型为水化活性较高的M1型。 （2）SrO在BSAC熟料中的适宜掺量为3%-5%，其1d，3d，7d，28d净浆抗压强度分别达到8.4MPa、35.8MPa、71.3MPa及103.7MPa；掺入1%MgO时水泥早期力学性能较高，其1d，3d，7d及28d抗压强度分别为14.7MPa、23.9MPa、34.4MPa和75.5MPa；该水泥熟料体系可容纳更多MgO，当熟料中掺有7%MgO时水泥安定性仍然良好，其1d，3d，7d及28d抗压强度分别为33.6MPa、59.7MPa、89.1MPa及95.1MPa；当K2O掺量为2%时水泥1d，3d，7d及28d抗压强度可达14.9MPa、48.6MPa、75.7MPa及106.5MPa。Na2O掺量为0.5%时，，水泥达到抗压强度最高，其1d，3d，7d及28d抗压强度分别为13.9MPa、40.7MPa、76.6MPa及108.9MPa。 （3）掺杂SrO，MgO，Na2O及K2O后，熟料中贝利特主要以α’-C2S存在；掺杂SrO后C3S主要以M3型存在，同时含有少量的M1及M2型；对于掺有MgO的熟料， C3S表现为M1型与M3型共存的特征，无M2型C3S；通过水化放热曲线可以看出，熟料3d水化速率顺序为：掺杂5%SrO掺杂7%MgO1%MgO无掺试样和0.5%Na2O2%K2O无掺试样。掺杂5%SrO试样的3d最大水化速率点是掺杂1%MgO和无掺试样的2.5倍。对Na2O和K2O而言，呈现出以下顺序：0.5%Na2O2%K2O无掺试样。 （4）通过研究煅烧制度对水泥熟料微结构和力学性能的影响，得到掺杂2%K2O的水泥硬化浆体7d和14d抗压强度在快速煅烧条件下（从室温以30℃/min的升温速率升至510℃；从510℃至810℃以20℃/min速率升温；810-1380℃以10℃/min升温）比普通煅烧制度（5℃/min的升温速率升至1380℃）下均高出10MPa左右的结论，归因于此时硅酸盐相的生成量增加，此时阿利特主要为M1型，贝利特为α-C2S和少量β-C2S；相比快速煅烧制度，液氮冷却工艺对硅酸盐相形成和稳定高温晶型并无显著影响。
[Abstract]:Traditional Portland cement has the disadvantages of high energy consumption and high CO2 emission from high quality limestone resources, and its volume stability and durability need to be further improved. BSAC) is one of the environmentally friendly cement systems with excellent long-term mechanical properties, but its early mechanical properties are still insufficient. The purpose of this paper is to introduce trace components and improve the calcination system. By adjusting the microstructure of silicate phase -belit and alite in clinker, the reaction activity of silicate phase can be further improved by stabilizing its high-temperature and high-activity crystal form or distorting the lattice, so as to improve the early strength of cement. The main findings are as follows: For the single ore system of C _ 2S, the main crystal forms of C _ 2S are 尾 -C2S and 纬 -C2S under the action of trace components, and the order of stabilizing 尾 -C2S is: the size of 尾 -C2S is in the order of 尾 -SO3SrONa2OK2OBaO, which has a certain effect on the stabilization of 伪 L'-C2S, but the stabilization effect of Na2O and K2O is weak; The composite doping can further reduce the pulverization rate of the sample and stabilize the high temperature crystal form of C _ 2S. For the single ore system of C _ 3s, the crystal forms of C _ 3s are mainly T type and M type under the action of trace components, in which MgO plays an important role in stabilizing M3-C3S. It can even stabilize R-type C3S, doping 1.5-3O has obvious effect on stabilizing M-type C3S, doping 0.5%-1.5%Na2O can make C3S stable to M-type, doping 1%SrO can make C3S change from T-type to M-type, and the main crystal form of C3S is T type in the presence of K2O, and doping 1%SrO can make C3S change from T-type to M-type. In the clinker with synergistic effect of mesophase and trace components, Berlitt is mainly 伪 -C2S.The Allitt crystal form is M1 type with higher hydration activity when C3A/C4AF=2:5 is used. The suitable amount of BSAC clinker is 3- 5, and the compressive strength of clean slurry is up to 8.4 MPA and 103.7 MPA, respectively, and the mechanical properties of cement at early stage are higher when 1%MgO is added, and the compressive strength of clean slurry reaches 8.4MPA ~ 35.8 MPA and 103.7MPa respectively at 1 d ~ 3 d ~ 7 d ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1). The compressive strength of the cement clinker system is 14.7 MPA and 75.5 MPA respectively, and the cement clinker system can hold more MgO, and the cement stability is still good when 7%MgO is added into the clinker. The compressive strength of the cement is 33.6 MPA (33.6 MPA) and 59.7 MPA (89.1MPa) and 95.1 MPa (28d) respectively, and the compressive strength of cement (48.6MPa 75.7 MPA) and 106.5MPa.Na2O (28d) is up to 14.9 MPA and 28d when the K2O content is 2, and the compressive strength of cement is 13.9 MPA and 108.9MPa, respectively, when the content of K2O is 2, the compressive strength of the cement is 39.6 MPA and 95.1 MPa respectively, and the compressive strength of the cement is 48.6MPa and 108.9MPa respectively when the content of K2O is 2, and the compressive strength of the cement is 48.6MPa and 108.9MPa respectively, when the content of K2O is 2, the compressive strength of the cement is 39.6 MPA and 28d respectively. (3) after doped with SrOO, MgO, Na 2O and K 2O, Berlitt in clinker mainly exists as 伪 -C _ 2S, C _ 3s mainly exists as M _ 3 type after doping SrO, and there is a little M _ 1 and M _ 2 type, for clinker with MgO, C _ 3s is characterized by coexistence of M _ 1 type and M _ 3 type, and C _ 3s is characterized by coexistence of M _ 1 type and M _ 3 type in clinker. From the hydration exothermic curves, it can be seen that the order of hydration rate of clinker is as follows: doped 5%SrO doped 7%MgO1%MgO without doping and 0.5%Na2O2%K2O without doping. The maximum hydration rate of doped 5%SrO samples is 2.5 times of that of doped 1%MgO and undoped samples. For Na2O and K _ 2O, the following order is presented: 0.5 and Na _ 2O _ 2K _ 2O _ free samples. 4) by studying the effect of calcination system on the microstructure and mechanical properties of cement clinker, the compressive strength of cement hardened paste doped with 2%K2O was obtained under the condition of fast calcination (from room temperature to 510 鈩

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