Email Alerts
RSS
Properties of fly ash geopolymer with calcium aluminate cement as an additive
-
摘要: 为探讨铝酸盐水泥对粉煤灰基地聚合物性能的影响规律，用掺量分别为0、2%、4%、8%和12%铝酸盐水泥代替粉煤灰，运用SEM、XRD、FTIR与TG等测试方法，对复掺铝酸盐水泥的地聚合物进行微观机理探究；开展流动度试验、凝结时间与抗压强度试验，对复掺铝酸盐水泥的地聚合物进行宏观性能分析。结果表明，当铝酸盐水泥掺量从0增长到12%的过程中，C-S-H凝胶含量从2.16%增长到8.10%，富铝凝胶含量从55.22%增长到74.60%，增大铝酸盐水泥掺量，流动度从22.4 cm降低到21.5 cm，初凝时间从622 min减小到106 min，终凝时间从740 min减小到125 min，抗压强度从27.7 MPa增长到70.78 MPa。因此，复掺铝酸盐水泥有利于生成更多的C-S-H凝胶和富铝凝胶，C-S-H凝胶具有更大的生成速率，降低了地聚合物工作性能，增大了地聚合物抗压强度，丰富了地聚合物性能的提高方法。Abstract: In this study, the influence of calcium aluminate cement on the properties of fly ash based geopolymer was analysed. Calcium aluminate cement was used to replace fly ash, and the content was 0%, 2%, 4%, 8% and 12%, respectively. SEM, XRD, FTIR and TG were used to explore the micro-mechanism of geopolymer with calcium aluminate cement; fluidity test, setting time and compressive strength test were carried out to analyze the macro-performance of geopolymer with calcium aluminate cement. The results show that when the content of calcium aluminate cement increases from 0% to 12%, the content of C-S-H gel increases from 2.16% to 8.1%, and the content of aluminium-rich gel grows from 55.22% to 74.6%. Increasing the content of calcium aluminate cement, the fluidity decreases from 22.4 cm to 21.5 cm, initial setting time decreases from 622 min to 106 min, final setting time drops from 740 min to 125 min, and the compressive strength increases from 27.7 MPa to 70.78 MPa. Therefore, adding calcium aluminate cement is beneficial to the formation of more C-S-H gel and aluminum rich gel, and C-S-H gel has a greater generation rate, which reduces the working performance and improves the compressive strength of geopolymer, which enriches the method to improve the properties of geopolymer.
-
Key words:
- fly ash geopolymer /
- calcium aluminate cement /
- micro-mechanism /
- compressive strength
-
图 5 不同CAC掺量的FAG的非晶态与晶态相组成
Figure 5. Amorphous and crystalline phase compositions of FAG with different CAC contents
图 10 不同CAC掺量的FAG的抗压强度
Figure 10. Compressive strength of FAG with different CAC contents
表 1 粉煤灰与CAC的主要化学组分
Table 1. Main chemical compositions of fly ash and CAC
单位：% 样品 SiO2 Al2O3 Fe2O3 CaO MgO K2O Na2O SO3 粉煤灰 48.73 33.41 5.19 4.81 1.79 1.61 1.29 1.04 CAC 7.21 48.89 2.01 35.56 0.41 0.61 0.13 0.71 
下载: 导出CSV
表 2 粉煤灰的物理性能
Table 2. Physical properties of fly ash
样品 密度/(kg·m−3) 细度/% 活性指数/% 需水量比/% 烧失量/% 粉煤灰 2 284.6 8.6 90.2 87.2 1.8
下载: 导出CSV
表 3 CAC的物理与力学性能
Table 3. Physical and mechanical properties of CAC
样品 密度/
(kg·m−3)细度/
(m2·kg−1)凝结时间/
min抗压强度/
MPa抗折强度/
MPa初凝 终凝 7 d 28 d 7 d 28 d CAC 3 168 360 108 276 48.1 61.5 6.3 8.8
下载: 导出CSV
表 4 地聚合物组分
Table 4. Mix proportions of FAG
单位：kg/m3 Mix CAC/% 粉煤灰 Na2SiO3 NaOH H2O CAC M-0 0 1 134.4 323.0 74.1 235.1 0 M-1 2 1 111.7 323.0 74.1 235.1 22.7 M-2 4 1 089.1 323.0 74.1 235.1 45.4 M-3 8 1 043.7 323.0 74.1 235.1 90.8 M-4 12 998.3 323.0 74.1 235.1 136.1
下载: 导出CSV
表 5 不同CAC掺量的FAG质量损失
Table 5. Weight loss of FAG with different CAC contents
单位：% 掺量 总失重 自由水蒸发 C-S-H/Si-OH分解 CaCO3分解 0 10.98 3.31 2.55 1.81 2 11.80 3.69 3.03 0.76 4 11.44 3.19 3.36 0.77 8 11.60 3.24 3.20 0.73 12 11.73 3.20 3.31 0.74
下载: 导出CSV
-
[1] DAVIDOVITS J. Geopolymers: inorganic polymeric new materials[J]. Journal of Thermal Analysis, 1991, 37(8): 1633-1656. doi: 10.1007/BF01912193 [2] MEHTA A, SIDDIQUE R. Sustainable geopolymer concrete using ground granulated blast furnace slag and rice husk ash: strength and permeability properties[J]. Journal of Cleaner Production, 2018, 205: 49-57. doi: 10.1016/j.jclepro.2018.08.313 [3] KHALE D, CHAUDHARY R. Mechanism of geopolymerization and factors influencing its development: a review[J]. Journal of Materials Science, 2007, 42(3): 729-746. doi: 10.1007/s10853-006-0401-4 [4] WAN Q, RAO F, SONG S X, et al. Geopolymerization reaction, microstructure and simulation of metakaolin-based geopolymers at extended Si/Al ratios[J]. Cement and Concrete Composites, 2017, 79: 45-52. doi: 10.1016/j.cemconcomp.2017.01.014 [5] 李克亮, 蒋林华, 黄国泓, 等. 地聚合物复合水泥混凝土性能研究[J]. 水利水运工程学报,2006(1):49-53. (LI Keliang, JIANG Linhua, HUANG Guohong, et al. Property study of geopolymer blend cement concrete[J]. Hydro-Science and Engineering, 2006(1): 49-53. (in Chinese) doi: 10.3969/j.issn.1009-640X.2006.01.010 [6] DUAN P, YAN C J, ZHOU W. Influence of partial replacement of fly ash by metakaolin on mechanical properties and microstructure of fly ash geopolymer paste exposed to sulfate attack[J]. Ceramics International, 2016, 42(2): 3504-3517. doi: 10.1016/j.ceramint.2015.10.154 [7] NATH P, SARKER P K. Use of OPC to improve setting and early strength properties of low calcium fly ash geopolymer concrete cured at room temperature[J]. Cement and Concrete Composites, 2015, 55: 205-214. doi: 10.1016/j.cemconcomp.2014.08.008 [8] KUSBIANTORO A, NURUDDIN M F, SHAFIQ N, et al. The effect of microwave incinerated rice husk ash on the compressive and bond strength of fly ash based geopolymer concrete[J]. Construction and Building Materials, 2012, 36: 695-703. doi: 10.1016/j.conbuildmat.2012.06.064 [9] 杨芮齐. 粉煤灰-矿渣地聚合物泡沫混凝土的性能研究[D]. 鞍山: 辽宁科技大学, 2020. YANG Ruiqi. The properties research of fly ash-slag based geopolymer foam concrete[D]. Anshan: University of Science and Technology Liaoning, 2020. （in Chinese） [10] 龙伏梅, 胡明玉, 丁再涛, 等. 粉煤灰地聚合物材料及性能研究[J]. 南昌大学学报·工科版,2006,28(2):173-176. (LONG Fumei, HU Mingyu, DING Zaitao, et al. Study on the fly ash geopolymer material and its property[J]. Journal of Nanchang University (Engineering & Technology), 2006, 28(2): 173-176. (in Chinese) [11] 刘鑫, 彭泽川, 潘晨豪, 等. 纳米二氧化硅改性粉煤灰地聚合物力学性能及微观分析[J]. 材料导报,2020,34(22):22078-22082. (LIU Xin, PENG Zechuan, PAN Chenhao, et al. Mechanical properties and microscopic analysis of nano-silica modified fly ash geopolymer[J]. Materials Reports, 2020, 34(22): 22078-22082. (in Chinese) doi: 10.11896/cldb.19080113 [12] CRIADO M, PALOMO A, FERNÁNDEZ-JIMÉNEZ A. Alkali activation of fly ashes. Part 1: effect of curing conditions on the carbonation of the reaction products[J]. Fuel, 2005, 84(16): 2048-2054. doi: 10.1016/j.fuel.2005.03.030 [13] VAFAEI M, ALLAHVERDI A. Influence of calcium aluminate cement on geopolymerization of natural pozzolan[J]. Construction and Building Materials, 2016, 114: 290-296. doi: 10.1016/j.conbuildmat.2016.03.204 [14] HIDALGO A, GARCÍA J L, ALONSO M C, et al. Microstructure development in mixes of calcium aluminate cement with silica fume or fly ash[J]. Journal of Thermal Analysis and Calorimetry, 2009, 96(2): 335-345. doi: 10.1007/s10973-007-8439-3 [15] REES C A, PROVIS J L, LUKEY G C, et al. In situ ATR-FTIR study of the early stages of fly ash geopolymer gel formation[J]. Langmuir the Acs Journal of Surfaces and Colloids, 2007, 23(17): 9076-9082. doi: 10.1021/la701185g -
点击查看大图
图(10) / 表 (5)
计量
- 文章访问数: 292
- HTML全文浏览量: 110
- PDF下载量: 26
- 被引次数: 0
