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纳米复合水泥中ZrO2纳米粉体作用机理初探 总被引:1,自引:0,他引:1
高强和高性能胶凝材料研究是当前研究的新亮点。随着纳米材料科学技术发展.纳米材料制备和应用已日益普及。低温强碱合成法制得的纳米ZrO2粉体,具有特征的纳米颗粒效应和相变过程。在一定条件下掺入水泥中,起到填隙和镶嵌作用.改善了水泥产物微观结构并提高了其抗压强度。介绍了纳米ZrO2粉体制备过程,该粉体形貌特征和粒径分析以及相变机理。 相似文献
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掺纳米SiO2高性能混凝土研究进展 总被引:1,自引:0,他引:1
纳米材料的问世及其在诸多工程领域的成功应用,为改善传统混凝土的性能开辟了新途径.纳米SiO2粉体因其特殊的表面与界面效应以及来源广泛、经济性好等特征,成为目前纳米混凝土研究中最常见的纳米改性剂.综述了目前国内外掺纳米SiO2高性能混凝土的制备工艺、工作性能、力学性能和耐久性等相关研究;并结合本研究组的试验成果,分析了纳米SiO2粉体掺量对纳米混凝土强度的影响规律以及纳米材料对混凝土强度的改善机理;概述了纳米SiO2对混凝土自收缩性能、抗氯离子渗透性能、抗冻耐久性的影响,并对掺纳米SiO2高性能混凝土的未来研究方向提出了积极建议. 相似文献
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纳米氧化铝纤维改性酚醛树脂及性能 总被引:3,自引:0,他引:3
采用原位法成功合成了摩擦材料用纳米氧化铝纤维改性酚醛树脂.利用示差扫描量热分析(DSC)对合成树脂的固化反应及其动力学进行了研究,结果表明:纳米氧化铝纤维可降低酚醛树脂的固化温度和表观活化能.通过热重分析(TGA)对合成树脂的热性能进行了研究,结果显示,纳米氧化铝纤维对酚醛树脂热性能的影响较小.通过冲击强度测试和断口形貌分析研究了合成树脂的韧性,结果表明,纳米氧化铝纤维对酚醛树脂韧性有显著影响;随着纳米氧化铝纤维含量的增加,改性树脂的冲击强度先增大,后减小,在含量为1.8%时,达到最大值,与纯酚醛树脂相比,提高了约91%. 相似文献
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Solid waste management in developing countries is often unsustainable, relying on uncontrolled disposal in waste dumps. Particular problems arise from the disposal of treatment residues generated by removing arsenic (As) from drinking water because As can be highly mobile and has the potential to leach back to ground and surface waters. This paper reviews the disposal of water treatment wastes containing As, with a particular emphasis on stabilisation/solidification (S/S) technologies which are currently used to treat industrial wastes containing As. These have been assessed for their appropriateness for treating As containing water treatment wastes. Portland cement/lime mixes are expected (at least in part) to be appropriate for wastes from sorptive filters, but may not be appropriate for precipitative sludges, because ferric flocs often used to sorb As can retard cement hydration. Brine resulting from the regeneration of activated alumina filters is likely to accelerate cement hydration. Portland cement can immobilise soluble arsenites and has been successfully used to stabilise As-rich sludges and it may also be suitable for treating sludges generated from precipitative removal units. Oxidation of As(III) to As(V) and the formation of calcium-arsenic compounds are important immobilisation mechanisms for As in cements. Geopolymers are alternative binder systems that are effective for treating wastes rich in alumina and metal hydroxides and may have potential for As wastes generated using activated alumina. The long-term stability of cemented, arsenic-bearing wastes is however uncertain, as like many cements, they are susceptible to carbonation effects which may result in the subsequent re-release of As. 相似文献
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溶胶改性水泥基材料的探讨 总被引:1,自引:0,他引:1
在众多外加物质(混合材料、掺和料、聚合物、减水剂、纳米级矿粉等)改性水泥基材料的基础上,提出了使用溶胶改善水泥材料结构和性能的方案.溶胶的胶粒尺寸在纳米级范围.硅溶胶与铝溶胶都可以作为配制高性能水泥基材料的外加剂.掺入硅溶胶,可以明显提高水泥净浆和混凝土的力学性能.与纳米SiO2相比,硅溶胶具有掺量较少、分散性好和价格较低的优势. 相似文献
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丁苯橡胶改善高铝水泥石 总被引:2,自引:0,他引:2
梁乃兴 《混凝土与水泥制品》1994,(5):11-13
本文研究了丁苯橡胶对高铝水泥石物理力学性能的改善。从凝结时间及初期水化热研究了丁苯橡胶对高铝水泥水化过程的影响。用扫描电镜观察分析了高铝水泥石微观结构形态的改变。 相似文献
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ABSTRACTIn order to improve its transesterification process, performance and emission parameters, nanoparticles are mixed to neat biodiesel. This work aims to investigate the cause of alumina nanoparticles on transesterification, emission and performance of coconut biodiesel. Two fuel samples are prepared by transesterification process with and without adding alumina nanoparticles. Experimental results revealed that the nitrogen oxide emission and smoke emission are reduced by 6% and 8% for coconut biodiesel by transesterification with adding alumina nanoparticles (CBD100A) when compared to coconut biodiesel by transesterification without alumina nanoparticles (CBD100). In addition, the introduction of alumina nanoparticles in coconut biodiesel during transesterification reduces the unburned hydrocarbon, carbon monoxide emissions considerably. Experimental results show that the CBD100A reduces fuel consumption which increases brake thermal efficiency. 相似文献
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石灰石粉对高铝水泥性能的影响 总被引:2,自引:0,他引:2
研究了石灰石粉对高铝水泥胶砂试件强度及孔结构的影响,分析了石灰石粉在高铝水泥水化过程中的作用.结果表明:高铝水泥胶砂试件抗折强度和抗压强度均随石灰石粉掺量(质量分数,下同)的增加呈现先升高后降低的趋势,各龄期(1,3,7,28d)胶砂试件的抗折强度与抗压强度均在石灰石粉掺量为3%时达到最大值;适量石灰石粉掺入高铝水泥中可生成单碳型水化碳铝酸钙和氢氧化铝,提高胶砂试件的密实度和强度;高铝水泥胶砂试件28d总孔隙率、大孔孔隙率和小孔孔隙率均随石灰石粉掺量的增加呈现先减小后增大的趋势,当石灰石粉掺量为3%时,胶砂试件各孔隙率均最小. 相似文献