Experimental Parameter Control of SHPB Based on the Geopolymer Concrete
-
摘要: 为有效地测试地质聚合物混凝土的冲击力学特性,以矿渣、粉煤灰为原材料,制备了高流态的C30地质聚合物混凝土,探索了此类混凝土的霍普金森压杆(SHPB)实验技术参数的控制规律,得到了射弹速度、整形器直径与最佳近似恒应变率之间的关系。结果表明:波形整形技术消除了波形振荡现象,有效地降低了弥散效应;整形后应力波形的前沿升时远远高于传统矩形波的前沿升时,保证了应力的均匀性;通过组合控制射弹速度和整形器直径,实现了恒应变率加载。Abstract: In order to test the impact mechanical properties of geopolymer concrete (GC) effectively, the slag and fly ash were used to fabricate the highly fluidized C30 GC.Based on the prepared GC, the parameter control of split Hopkinson pressure bar (SHPB) system was investigated, and the law between striker velocity, pulse shaper diameter and the optimum constant strain rate was obtained.The results indicate that the pulse shaping technique eliminates the phenomenon of wave oscillation and reduces the dispersion effect effectively; the rise time of the stress wave after shaping is higher than that of rectangular wave, which guarantees the dynamic stress equilibrium; a nearly constant strain-rate loading can be achieved through the integrated control of striker velocity and pulse shaper diameter.
-
表 1 矿渣和粉煤灰的化学组成(质量分数)
Table 1. Chemical compositions of slag and fly ash (Mass fraction)
(%) Material SiO2 Al2O3 Fe2O3 CaO Na2O TiO2 MgO K2O P2O5 SO3 Slag 29.2 19.4 5.8 38.6 0.2 0.6 2.8 0.1 2.6 Fly ash 45.8 21.4 12.6 13.7 1.1 0.2 1.3 1.8 0.1 1.9 表 2 ${{{\bar{\dot{\varepsilon }}}}_{\text{optimum}}}$与d和v的关系
Table 2. Relationship among ${{{\bar{\dot{\varepsilon }}}}_{\text{optimum}}}$, d and v
${{{\bar{\dot{\varepsilon }}}}_{\text{optimum}}}$/(s-1) d/(mm) v/(m/s) 10 8.2 2.59 20 15.9 3.58 30 20.4 4.57 40 23.6 5.56 50 26.0 6.55 60 28.1 7.54 70 29.8 8.53 80 31.3 9.52 90 32.6 10.51 100 33.7 11.50 110 34.8 12.50 120 35.8 13.49 130 36.7 14.48 140 37.5 15.47 150 38.2 16.46 160 39.0 17.45 -
[1] Purdon A O. The action of alkalis on blast-furnace slag[J]. J Soc Chem Ind, 1940, 59: 191-202. doi: 10.1002/jctb.5000591202 [2] Shi C J, Krivenko P, Roy D. Alkali-Activated Cements and Concretes[M]. Boca Raton, USA: CRC Press, 2006. [3] Shen X D, Yan S, Wu X Q, et al. Immobilization of stimulated high level wastes into AASC waste form[J]. Cem Concr Res, 1994, 24(1), 133-138. doi: 10.1016/0008-8846(94)90094-9 [4] Shi C, Fernndez-Jiménez A. Stabilization/solidification of hazardous and radioactive wastes with alkali-activated cements[J]. J Hazard Mater, 2006, 137(3): 1656-1663. doi: 10.1016/j.jhazmat.2006.05.008 [5] Duxson P, Lukey G C, van Deventer J S J. The thermal evolution of metakaolin geopolymers: Part 2 Phase stability and structural development[J]. J Non-Cryst Solids, 2007, 353(22/23): 2186-2200. http://www.sciencedirect.com/science/article/pii/S0022309307003080 [6] Talling B, Brandstetr J. Present state and future of alkali-activated slag concrete[C]//Proeeedings of 3rd International Conference on Fly Ash, Silica Fume, Slag and Natural Pozzolans in Concrete. Trondheim, Norway, 1989. [7] Mirandaa J M, Fernndez-Jiménezb A, Gonzlez J A, et al. Corrosion resistance in activated fly ash mortars[J]. Cem Concr Res, 2005, 35(5): 1210-1217. http://www.sciencedirect.com/science/article/pii/S0008884604003515 [8] Bakharev T. Durability of geopolymer materials in sodium and magnesium sulfate solutions[J]. Cem Concr Res, 2005, 35(6): 1233-1246. doi: 10.1016/j.cemconres.2004.09.002 [9] Jambunathan N, Sanjayan J G, Pan Z, et al. The role of alumina on performance of alkali-activated slag paste exposed to 50 ℃[J]. Cem Concr Res, 2013, 54: 143-150. doi: 10.1016/j.cemconres.2013.09.009 [10] Shaikh F U A. Review of mechanical properties of short fibre reinforced geopolymer composites[J]. Constr Build Mater, 2013, 43: 37-49. doi: 10.1016/j.conbuildmat.2013.01.026 [11] Luo X, Xu J Y, Bai E L, et al. Mechanical properties of ceramics-cement based porous material under impact loading[J]. Mater Des, 2014, 55: 778-784. doi: 10.1016/j.matdes.2013.10.046 [12] 许金余, 罗鑫, 吴菲, 等.地质聚合物混凝土动态劈裂拉伸破坏的吸能特性[J].空军工程大学学报(自然科学版), 2013, 14(5): 85-88. http://d.wanfangdata.com.cn/Periodical/kjgcdxxb201305020Xu J Y, Luo X, Wu F, et al. Energy absorption capacities of geopolymer concrete under condition of dynamic splitting-tensile damage[J]. Journal of Air Force Engineering University(Natural Science Edition), 2013, 14(5): 85-88. (in Chinese) http://d.wanfangdata.com.cn/Periodical/kjgcdxxb201305020 [13] 王礼立, 朱兆祥.应力波基础[M].北京: 国防工业出版社, 2005.Wang L L, Zhu Z X. Foundation of Stress Waves[M]. Beijing: National Defense Industry Press, 2005. (in Chinese) [14] Frew D J, Forrestal M J, Chen W. Pulse shaping techniques for testing brittle materials with a split hopkinson pressure bar[J]. Exp Mech, 2002, 42(1): 93-106. doi: 10.1007/BF02411056 [15] Li W M, Xu J Y. Impact characterization of basalt fiber reinforced geopolymeric concrete using a 100-mm-diameter split Hopkinson pressure bar[J]. Mater Sci Eng A, 2009, 513: 145-153. http://www.sciencedirect.com/science/article/pii/S0921509309001890 [16] Lok T S, Zhao P J. Impact response of steel fiber-reinforced concrete using a split Hopkinson pressure bar[J]. J Mater Civ Eng, 2004, 16(1): 54-59. doi: 10.1061/(ASCE)0899-1561(2004)16:1(54) [17] 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]. J Exp Mech, 2006, 21(1): 51-60. http://www.cqvip.com/Main/Detail.aspx?id=21314398 [18] 左宇军, 唐春安, 朱万成, 等.岩石类介质SHPB试验加载波形的数值分析[J].东北大学学报(自然科学版), 2007, 28(6): 859-862.Zuo Y J, Tang C A, Zhu W C, et al. Numerical analysis of loading waveform in SHPB tests of rock-like medium[J]. Journal of Northeastern University(Natural Science), 2007, 28(6): 859-862. (in Chinese) [19] 刘孝敏, 胡时胜.大直径SHPB弥散效应的二维数值分析[J].实验力学, 2000, 15(4): 371-376. http://www.cnki.com.cn/Article/CJFDTotal-SYLX200004002.htmLiu X M, Hu S S. Two-dimensional numerical analysis for the dispersion of stress waves in large-diameter-SHPB[J]. Journal of Experimental Mechanics, 2000, 15(4): 371-376. (in Chinese) http://www.cnki.com.cn/Article/CJFDTotal-SYLX200004002.htm [20] 李夕兵, 古德生.岩石冲击动力学[M].长沙: 中南工业大学出版社, 1994.Li X B, Gu D S. Rock Impact Dynamics[M]. Changsha: Central South University of Technology Press, 1994. (in Chinese) [21] 罗鑫, 许金余, 李为民, 等.应力脉冲在SHPB实验中弥散效应的数值模拟与频谱分析[J].实验力学, 2010, 25(4): 451-456. http://www.cnki.com.cn/Article/CJFDTotal-SYLX201004015.htmLuo X, Xu J Y, Li W M, et al. Numerical simulation and spectrum analysis of dispersion effect of stress pulse in SHPB experiment[J]. Journal of Experimental Mechanics, 2010, 25(4): 451-456. (in Chinese) http://www.cnki.com.cn/Article/CJFDTotal-SYLX201004015.htm [22] 周子龙, 李夕兵, 赵国彦, 等.岩石类SHPB实验理想加载波形的三维数值分析[J].矿冶工程, 2005, 25(3): 18-20. http://d.wanfangdata.com.cn/Periodical/kygc200503006Zhou Z L, Li X B, Zhao G Y, et al. Three dimensional numerical analysis of perfect loading wave form of rock with SHPB[J]. Mining and Metallurgical Engineering, 2005, 25(3): 18-20. (in Chinese) http://d.wanfangdata.com.cn/Periodical/kygc200503006 [23] Ravichandran G, Subhash G. Critical appraisal of limiting strain rates for compression testing of ceramics in a split Hopkinson pressure bar[J]. J Am Ceram Soc, 1994, 77(1): 263-267. doi: 10.1111/j.1151-2916.1994.tb06987.x