Deformation behaviors of highly-fluidized geopolymer concrete during dynamic compression at high strain rates

作者：Luo Xin^*; Xu Jin Yu; Su Hao Yang; Li Wei Min; Bai Er Lei

来源：Explosion and Shock Waves, 2014, 34(2): 216-222.

• Deformation behavior
• Dynamic compression tests
• Geopolymer concrete
• Pulse shaping techniques
• Solid mechanics

The highly-fluidized geopolymer concrete (HFGC) with the strength grade of C30 was prepared by using slag and fly ash as raw material as well as NaOH and Na2CO3 as 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 10 to 100 s-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 function Εc = -1.2×10-6Ε˙¯2 + 1.6×10-4Ε˙¯+0.0017, and the critical strain rate of deformation behaviors is 66.7 s-1. The dynamic elastic moduli of the HFGC are lower than the quasi-static ones.

• 出版日期2014
• 单位Polytechnic university