纳米二氧化硅改性超高韧性水泥基复合材料冲击压缩试验研究

发布时间：2018-01-09 09:28

本文关键词：纳米二氧化硅改性超高韧性水泥基复合材料冲击压缩试验研究　出处：《工程力学》2017年02期 　论文类型：期刊论文

【摘要】：该文采用Ф80 mm的分离式霍普金森压杆装置,研究了纳米改性后的UHTCC(ultra high toughness cementitious composites)在高速冲击压缩应力状态下的力学响应,并与常规UHTCC材料、钢纤维混凝土进行了对比。试验得到了各组材料在准静态和动态共计4组应变率(2.36×10~(-5) s~(-1)、120 s~(-1)、160 s~(-1)、200 s~(-1))下的准静态压缩强度及冲击压缩应力-应变曲线,并计算了各组试件的耗能能力。为了进一步优化材料的抗冲击性能,该文还研究了纳米改性后的UHTCC基体中钢纤维和PVA纤维的混杂效果。试验结果表明:5组材料均具有应变率敏感性,峰值应力和耗能能力随着应变率的增大而上升;经过纳米改性后的UHTCC材料冲击压缩力学强度及耗能能力明显提高;在冲击荷载下,钢纤维和PVA纤维产生正混杂效应,提高钢纤维掺量可以强化UHTCC的抗冲击能力;应变率的大小和钢纤维的掺量之间的关系影响了动态峰值应力的提升。
[Abstract]:This paper adopts the device of 80 mm diameter split Hopkinson pressure bar, the research of nano modified UHTCC (ultra high toughness cementitious composites) in high speed impact compressive mechanical response under stress, compared with the conventional UHTCC materials were compared. The test of steel fiber reinforced concrete material under quasi-static and dynamic groups a total of 4 sets of strain rate (2.36 * 10~ (-5) s~ (-1), 120 s~ (-1), 160 s~ (-1), 200 s~ (-1)) under quasi-static strength and shock compression stress-strain curves of specimens, the energy dissipation capacity is calculated. In order to further optimize the material the anti shock performance, the paper also studied the effect of hybrid nano modified UHTCC matrix of steel fiber and PVA fiber. The results showed that: 5 groups of materials have strain rate sensitivity, peak stress and energy dissipation capacity with the strain rate increasing and increased; after nano modified UHTCC The impact compressive mechanical strength and energy dissipation capacity is obviously increased; under the impact load, steel fiber and PVA fiber positive hybrid effect, improve the content of steel fiber can strengthen the UHTCC anti impact ability; relationship between dosage of strain rate and the size of steel fiber affects the dynamic peak stress increase.

【作者单位】：浙江大学高性能建筑结构与材料研究所;
【基金】：国家自然科学基金项目(51378462) 中央高校基本科研业务费专项资金项目(2014FZA4017)
【分类号】：TU528.572
【正文快照】： 军事防御体、核电站外壳、超大型桥梁等特殊构筑物在服役的过程中不仅要承受静载作用,还可能承受诸如地震、海啸、武器攻击、爆炸等强动载作用,这就要求此类建筑物具备一定的抗冲击和抗贯穿能力[1]。传统的混凝土材料由于本身的脆性较大,在较低冲击荷载下就会发生脆断。同时,

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