Deformation behaviors of highly-fluidized geopolymer concrete during dynamic compression at high strain rates
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摘要: 以矿渣、粉煤灰为原材料，以NaOH、Na2CO3为碱激发剂，制备了强度等级为C30的高流态地质聚合物混凝土（highly-fluidized geopolymer concrete，HFGC），运用波形整形技术改进了Ø100mm SHPB实验装置，通过参数控制保证应力均匀和恒应变率加载，对HFGC开展了动态压缩实验，分析了HFGC在冲击压缩荷载下的变形特性。HFGC属于应变率敏感材料和脆性材料，高应变率作用下，HFGC的典型应力应变曲线包括压实挤密阶段、弹性阶段和软化、屈服阶段。在10~100s-1的应变率范围内，HFGC的峰值应变εc随应变率的变化表现出明显的冲击韧化效应，εc随应变率的升高先增大后减小，满足二次函数关系εc＝-1.2×10-6
+1.6×10-4 +0.001 7，变形特性变化的临界应变率为66.7s-1。HFGC的动态弹性模量均低于其在准静态下的弹性模量。 -
关键词:
- 固体力学 /
- 变形特性 /
- 动态压缩实验 /
- 高流态地质聚合物混凝土 /
- 波形整形技术
Abstract: The highly-fluidized geopolymer concrete(HFGC)with the strength grade of C30was prepared by using slag and fly ash as raw material as well as NaOH and Na2CO3as alkali activator.Dynamic compression tests were carried out for the prepared HFGC specimens by using the 100-mm-diameter split Hopkinson pressure bar (SHPB)apparatus improved by the pulse-shaping technique.And in the dynamic compression tests, the dynamic stress equilibrium and the nearly constant strain rate loading were achieved by controlling the technique parameters.Based on the above tests, the deformation behaviors of the HFGC under the impact loadings were analyzed.The HFGC belongs to brittle and strain-rate sensitive materials.The typical stress-strain curve of the HFGC concludes compaction stage, elastic stage, softening and yielding stage at high strain rates.In the strain rate range from 10to 100s-1, the variation of the HFGC's peak strain with stain rate embodies obvious impact toughening, the peak strain increases firstly and then decreases with rising stain rate.And the overall change accords with the quadratic functionεc=-1.2×10-6+1.6×10-4 +0.001 7, and the critical strain rate of deformation behaviors is 66.7s-1.The dynamic elastic moduli of the HFGC are lower than the quasi-static ones. -
图 3 不同应变率下HFGC试样的应力应变曲线
Figure 3. Stress-strain curves of HFGC specimens at different strain rates
图 4 高应变率下HFGC试样典型的应力应变曲线
Figure 4. Typical stress-strain curve of HFGC specimens at high strain rate
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[1] Davidovits J. Geopolymers and geopolymeric materials[J]. Journal of Thermal Analysis and Calorimetry, 1989, 35(2): 429-441. doi: 10.1007/BF01904446 [2] Roy D M. New strong cement materials: Chemically bonded ceramics[J]. Science, 1987, 235(4789): 651-658. doi: 10.1126/science.235.4789.651 [3] Miranda J M, Fernández-Jiménez A, González J A, et al. Corrosion resistance in activated fly ash mortars[J]. Cement and Concrete Research, 2005, 35(6): 1210-1217. doi: 10.1016/j.cemconres.2004.07.030 [4] Bakharev T. Durability of geopolymer materials in sodium and magnesium sulfate solutions[J]. Cement and Concrete Research, 2005, 35(6): 1233-1246. doi: 10.1016/j.cemconres.2004.09.002 [5] Davidovits J. Geopolymers: Inorganic polymeric new materials[J]. Journal of Thermal Analysis and Calorimetry, 1991, 37(8): 1633-1656. doi: 10.1007/BF01912193 [6] Davidovits J. Properties of geopolymer cements[C]//First International Conference on Alkaline Cements and Concretes. 1994: 131-149. [7] Palomo A, Maclas A, Blaneo M T, et al. Physical chemical and mechanical characterization of geopolymers[C]//Proceedings of the 9th International Congress on the Chemistry of Cement. 1992: 505-511. [8] 吴中伟.绿色高性能混凝土与科技创新[J].建筑材料学报, 1997(6): 3-9. [9] 清华大学老科技工作者协会, 北京交通大学土建学院. CECS207: 2006高性能混凝土应用技术规程[S].北京: 中国计划出版社, 2006: 2. [10] 许金余, 李为民, 范飞林, 等.地质聚合物混凝土的冲击力学性能研究[J].振动与冲击, 2009, 28(1): 46-51. doi: 10.3969/j.issn.1000-3835.2009.01.011Xu Jin-yu, Li Wei-min, Fan Fei-lin, et al. Study on mechanical properties of geopolymeric concrete under impact loading[J]. Journal of Vibration and Shock, 2009, 28(1): 46-51. doi: 10.3969/j.issn.1000-3835.2009.01.011 [11] 李为民, 许金余.玄武岩纤维对混凝土的增强和增韧效应[J].硅酸盐学报, 2008, 36(4): 476-481. doi: 10.3321/j.issn:0454-5648.2008.04.009Li Wei-min, Xu Jin-yu. Strengthening and toughening in basalt fiber-reinforced concrete[J]. Journal of the Chinese Ceramic Society, 2008, 36(4): 476-481. doi: 10.3321/j.issn:0454-5648.2008.04.009 [12] Luo Xin, Xu Jin-yu, Bai Er-lei, et al. Systematic study on the basic characteristics of alkali-activated slag-fly ash cementitious material system[J]. Construction and Building Materials, 2012, 29: 482-486. doi: 10.1016/j.conbuildmat.2011.09.021 [13] Li Wei-min, Xu Jin-yu. Impact characterization of basalt fiber reinforced geopolymeric concrete using a 100-mmdiameter split Hopkinson pressure bar[J]. Materials Science and Engineering: A, 2009, 513-514: 145-153. doi: 10.1016/j.msea.2009.02.033 [14] 蔡瑞环, 欧阳东, 黄华县, 等.搅拌工艺对混凝土强度及氯离子渗透性影响实验研究[J].水运工程, 2008(3): 9-13. doi: 10.3969/j.issn.1002-4972.2008.03.003Cai Rui-huan, Ouyang Dong, Huang Hua-xian, et al. Experimental study on influence of chloride ion's permeability and strength of concrete by different mixing technologies[J]. Port and Waterway Engineering, 2008(3): 9-13. doi: 10.3969/j.issn.1002-4972.2008.03.003 [15] 湖南大学, 天津大学, 同济大学, 等.土木工程材料[M].北京: 中国建筑工业出版社, 2002: 90-101. [16] 陶俊林. SHPB实验技术若干问题研究[D].北京: 中国工程物理研究院, 2005: 21-29. [17] Lok T S, Li X B, Liu D, et al. Testing and response of large diameter brittle materials subjected to high strain rate[J]. Journal of Materials in Civil Engineering, 2001, 14(3): 262-269. [18] 胡泽斌, 许金余, 彭高丰, 等.冲击荷载作用下聚苯乙烯混凝土的吸能特性[J].硅酸盐学报, 2010, 38(7): 1173-1178.Hu Ze-bin, Xu Jin-yu, Peng Gao-feng, et al. Energy-absorption property of expanded polystyrene concrete under impact[J]. Journal of the Chinese Ceramic Society, 2011, 38(7): 1173-1178. [19] Frew D J, Forrestal M J, Chen W. Pulse shaping techniques for testing brittle materials with a split Hopkinson pressure bar[J]. Experimental Mechanics, 2002, 42(1): 93-106. doi: 10.1007/BF02411056 [20] Lee O S, Kim S H, Han Y H. Thickness effect of pulse shaper on dynamic stress equilibrium and dynamic deformation behavior in the polycarbonate using SHPB technique[J]. Journal of Experimental Mechanics, 2006, 21(1): 51-60. [21] 王礼立.应力波基础[M]. 2版.北京: 国防工业出版社, 2005: 30-74. [22] 罗鑫, 许金余, 苏灏扬, 等.冲击载荷下高流态地质聚合物混凝土的强度特性[J].建筑材料学报, 2014, 17(1): 72-77. doi: 10.3969/j.issn.1007-9629.2014.01.013Luo Xin, Xu Jin-yu, Su Hao-yang, et al. Strength properties of highly fluidized geopolymer concrete under impact loading[J]. Journal of Building Materials, 2014, 17(1): 72-77. doi: 10.3969/j.issn.1007-9629.2014.01.013 [23] Bishcholf P H, Pery S H. Compressive behavior of concrete at high strain rates[J]. Material and Structure, 1991, 144(24): 425-450. [24] 董毓利, 谢和平, 赵鹏.不同应变率下混凝土受压全过程的试验研究及其本构模型[J].水利学报, 1997(7): 72-77. doi: 10.3321/j.issn:0559-9350.1997.07.013Dong Yu-li, Xie He-ping, Zhao Peng. Experimental study and constitutive model on concrete under compression with different strain rate[J]. Journal of Hydraulic Engineering, 1997(7): 72-77. doi: 10.3321/j.issn:0559-9350.1997.07.013 [25] Tedasco J W, Ross C A. Strain-rate-dependent constitutive equation for concrete[J]. Journal of Pressure Vessel Technology, 1998, 120(4): 398-405. doi: 10.1115/1.2842350 [26] 余寿文, 冯西桥.损伤力学[M].北京: 清华大学出版社, 1997: 319-325. [27] 宁建国, 商霖, 孙远翔.混凝土材料动态性能的经验公式、强度理论与唯象本构模型[J].力学进展, 2006, 36(3): 389-405. doi: 10.3321/j.issn:1000-0992.2006.03.006Ning Jian-guo, Shang Lin, Sun Yuan-xiang. The research developments of dynamic constitutive relationship for concrete[J]. Advances in Mechanics, 2006, 36(3): 389-405. doi: 10.3321/j.issn:1000-0992.2006.03.006 [28] Sukontasukkul P, Nimityongskul P, Mindess S. Effect of loading rate on damage of concrete[J]. Cement and Concrete Research, 2004, 34(11): 2127-2134. doi: 10.1016/j.cemconres.2004.03.022 [29] Shkolnik I E. Effect of nonlinear response of concrete on its elastic modulus and strength[J]. Cement and Concrete Composites, 2005, 27(7/8): 747-757. https://www.sciencedirect.com/science/article/pii/S0958946505000065 [30] Dilger W H, Koch R, Kowalczyk R. Ductility of plain and confined concrete under different strain rates[J]. ACI Journal, 1984, 81(1): 73-81. https://www.concrete.org/publications/internationalconcreteabstractsportal/m/details/id/10649 -
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