可喷射PVA纤维增强水泥基复合材料基本性能试验研究

发布时间：2018-01-18 02:33

本文关键词：可喷射PVA纤维增强水泥基复合材料基本性能试验研究　出处：《广西大学》2013年硕士论文　论文类型：学位论文

【摘要】：PVA-ECC(Engineered cementitious composites,简称ECC),是近年来发展较快的一种以PVA(聚乙烯醇)纤维作为增强纤维的超高韧性水泥基复合材料。因其具有多缝开裂和显著的应变-硬化现象等传统水泥基材料所不具备的诸多优良性能,在国内外逐渐引起广泛关注。目前,对PVA-ECC的研究和应用大多集中在普通浇筑工作性能下,对其具有喷射施工性能时的相关研究较少。本文结合现有普通PVA-ECC的研究成果,对具备可喷射工作性能的PVA-ECC进行了初步探索和研究,主要工作内容和研究成果如下： (1)通过拌合物工作性能试验,研究了不同掺合料和掺量对工作性能的影响规律。研究结果表明：单掺50%粉煤灰或50%粉煤灰与偏高岭土、硅灰复掺时,在仅辅以高效减水剂条件下能够配制出满足简单喷射施工要求的PVA-ECC,并得到若干组配合比。 (2)通过抗压强度试验和薄板弯曲试验,研究了不同掺合料和掺量对基本力学性能的影响规律。研究结果表明：随着掺和料掺量增加对抗压强度不利,但可以明显提高抗弯性能；当在单掺50%粉煤灰基础上三种掺合料复掺时效果最好。 (3)通过快速碳化试验和电通量试验,研究了不同掺合料和掺量对抗碳化能力及抗氯离子渗透能力等耐久性的影响规律。研究结果表明：粉煤灰掺量超过30%会明显导致材料抗碳化性能降低,但抗氯离子渗透能力却有显著提高。当在单掺50%粉煤灰基础上复掺硅灰后,能够适当改善抗碳化性能；复掺偏高岭土后,对提高抗碳化性能不明显。偏高岭土、硅灰对阻止氯离子渗透有显著作用,偏高岭土效果更好于硅灰；与50%粉煤复掺后,可充分发挥叠加效应,尤其对早期抗氯离子渗透性能有更大提高作用。 (4)提出了可供具体工程喷射施工参考的PVA-ECC配合比建议。
[Abstract]:PVA-ECC(Engineered cementitious composites. PVA (polyvinyl alcohol) is a kind of polyvinyl alcohol (PVA), which has been developed rapidly in recent years. Fiber as a reinforced fiber super-high toughness cement matrix composites, because of its multi-joint cracking and remarkable strain-hardening phenomenon and other traditional cement-based materials do not have many excellent properties. At present, the research and application of PVA-ECC mainly focus on the general pouring performance. There are few related studies on the performance of jet construction. Combined with the existing research results of ordinary PVA-ECC, the PVA-ECC with jetting performance has been preliminarily explored and studied. The main work and findings are as follows: 1) the effects of different admixtures and contents on the performance of the mixture were studied. The results showed that only 50% fly ash or 50% fly ash were mixed with metakaolin. When the silica fume is mixed, PVA-ECCs which can meet the requirements of simple spray construction can be prepared under the condition of only adding superplasticizer, and some groups of mixing ratio can be obtained. 2) through the compressive strength test and the bending test of thin plate, the influence of different admixtures and contents on the basic mechanical properties is studied. The results show that the increase of the content of the admixture is unfavorable to the compressive strength. But the bending resistance can be improved obviously. The effect is the best when the three admixtures are mixed on the basis of 50% fly ash. Through rapid carbonization test and electric flux test. The effects of different admixtures and amounts on the durability such as resistance to carbonation and resistance to chloride ion penetration were studied. The results showed that the carbonation resistance of the materials decreased obviously when the content of fly ash exceeded 30%. However, the resistance to chloride ion permeation has been improved significantly. The carbonation resistance can be improved when the silica fume is added on the basis of 50% fly ash. After mixed with metakaolin, the carbonization resistance was not obviously improved. Metakaolin and silica fume had significant effect on preventing chloride ion permeation, and the effect of metakaolin was better than that of silica fume. When mixed with 50% pulverized coal, the superposition effect can be brought into full play, especially the resistance to chlorine ion permeation in the early stage can be improved more greatly. Finally, the paper puts forward the suggestion of PVA-ECC mix ratio which can be used as reference for specific project jet construction.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU528

【参考文献】