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本文简要介绍了铜渣的研究现状、主要化学组成和岩相特征,综述了铜渣在水泥领域中的应用对水泥砂浆性能的影响。铜渣中含有大量的2Fe O·Si O2和Fe3O4,可以作为吸波材料进行相关研究。铜渣的回收利用可以降低成本,保护环境,节约资源,具有广阔的应用前景和社会经济效应。 相似文献
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HPMC分散碳纤维的水泥砂浆电学性能研究 总被引:1,自引:1,他引:0
采用HPMC(羟丙基甲基纤维素)分散碳纤维,利用四电极法研究了内掺CCCW(水泥基渗透结品防水材料)的碳纤维石墨水泥砂浆试样水化期间和固化后的导电特性及在压缩循环荷载作用下的压阻特性.结果表明:随着固化龄期的增加,碳纤维石墨砂浆试样的电阻值逐渐增加,并且逐步趋于稳定.石墨掺入量越大,试样电阻达到稳定值所需的养护时间越短,试样的体积电阻率随石墨掺量的增加而下降.此外,在循环荷载作用下,石墨掺量为水泥质量分数的25%时,碳纤维石墨砂浆试样的体积电阻牢与压应力之间呈现良好的对应关系,电阻值在应力加载时几乎以线性下降,而卸载时增加.羟丙基甲基纤维素(HPMC)可以代替羧甲基纤维素(CMC)分散短切碳纤维以提高材料的耐霉性. 相似文献
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在介绍碳纳米管的结构特征、力学性能和含均匀分布的超细颗粒致密体系即DSP材料的特征、技术性能以及应用前景的基础上,分析了多壁碳纳米管增强DSP材料的可能性,得出拟解决的关键问题是碳纳米管在基体中的均匀分散和与基体的相容性,提出与分析化学专家合作是进行这一领域研究的一条高效途径. 相似文献
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Hosam.El_Din H. Seleem Alaa M. Rashad Tarek. Elsokary 《Construction and Building Materials》2011,25(2):1009-1017
Pozzolanas are readily available for use in concrete in the local markets for strength and/or durability enhancement. Although safety and security against disasters are not new, they still presuming a challenge. For instance, the fire resistive properties of concrete are of prime interest.Through this work, the effect of different kinds of pozzolana on the fire resistive properties of concrete was studied. Four types of pozzolana were incorporated into the concrete mixtures, i.e. metakaolin (MK), silica fume (SF), fly ash (FA), and ground granulated blast furnace slag (GGBS). Each of the employed pozzolana was used in two ratios: 10% and 20%, either in the form of cement replacement or as an addition without affecting the cement content. A total of 17 mixes were cast.For all mixtures, compressive strength is evaluated after 28 days of water curing. The mixtures’ compressive strengths were also evaluated after exposure to elevated temperatures: 200 °C, 400 °C, 600 °C, and 800 °C. The residual compressive strengths after heat exposure are evaluated. The formed cementitious phases after incorporation of pozzolana and the heat-induced transformations are investigated via the X-ray diffraction technique (XRD).Test results demonstrate the impact of each type of the employed pozzolana on the heat resistive properties of concrete in addition to their influence on the strength development of the investigated mixes. Therefore, a decision could be made regarding optimizing the benefits specific to each type of pozzolana and their employment method. 相似文献
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水泥砂浆固化土物理力学特性试验研究 总被引:6,自引:0,他引:6
为了解水泥砂浆固化土的掺砂量与强度之间的关系,找出具有工程应用前景的配比,在不同掺砂量不同龄期条件下对水泥砂浆固化土进行了无侧限抗压强度试验,研究了水泥砂浆固化土的强度和变形特性,分析了掺砂量和龄期对水泥砂浆固化土的强度和变形特性的影响。研究结果表明:在水泥土中掺入一定量的砂,可有效提高水泥土强度;一定水泥掺入比下,存在一个最佳掺砂量,使水泥砂浆固化土强度(qu)最高,变形系数(E50)最大;水泥砂浆固化土与水泥土的应力应变曲线均有明显的峰值,应力应变关系属加工软化型,其残余强度随着掺砂量的增加而增加;采用水泥砂浆搅拌桩加固软弱地基时,即使采用较高的掺砂量和置换率,加固体本身重量增加有限,下卧层附加应力增加也很小。 相似文献
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采用3种粒径(20、200、2 000目)的废玻璃粉等体积取代水泥胶砂中的标准砂,体积取代率分别为5%、10%、15%、20%,研究玻璃粉粒径和掺量对水泥胶砂的抗压强度和抗折强度的影响,并对玻璃粉水泥胶砂强度随龄期的变化规律进行了分析讨论。结果表明:不同粒径玻璃粉水泥胶砂的强度随玻璃粉掺量的变化规律存在较大的差异;在玻璃粉掺量相同的情况下,掺入较大粒径玻璃粉的水泥胶砂强度明显降低,玻璃粉粒径越小,强度降低程度越小,当玻璃粉粒径达到微米级,水泥胶砂的抗压强度和抗折强度均显著提高;玻璃粉水泥胶砂的抗压强度随龄期增长,早期强度增加的较快,后期发育增速变缓,而抗折强度早期增长的幅度较大,后期发育比较平缓。 相似文献
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针对引气减水剂在改善混凝土耐久性和工作性的同时,造成混凝土强度降低的问题,研究了改性木质素系高效减水剂GCL1与4种阴离子表面活性剂配伍后对水泥砂浆物理力学性能的影响。表面活性剂与GCL1的质量比为1∶100时,增强了溶液的起泡性能,LAS降低了GCL1的减水率和硬化砂浆的抗压强度和抗渗性能。AS和AES可使GCL1的砂浆减水率从15.4%提高到17.1%,K12可使GCL1的砂浆减水率提高到18.8%,AS和K12降低了砂浆的抗压强度和抗渗性。AES使掺GCL1砂浆的抗渗压力比提高了12%~18%。孔结构测试表明,GCL1与AES配伍后可在砂浆中引入细小、均匀的气泡,增加硬化水泥砂浆中小孔的数量,提高抗压强度和抗渗性能。 相似文献
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This study reports on the effects of multilayer graphene oxide (MGO) on compressive strength, flexural strength, and microstructure of cement mortar. The cement mortar was prepared with type P. II. 52.5 Portland cement, standard sand, and MGO. Four mixes were prepared with inclusion of MGO (0%, 0.02%, 0.04%, and 0.06% by weight of cement). The testing result shows that the compressive of GO-cement mortar increased by 4.84%–13.42%, and the flexural strength increased by 4.37%–8.28% at 3 d. GO-cement mortar’s compressive strength and flexural strength at 7 d increased by 3.84%–12.08% and 2.54%–13.43%, respectively. MGO made little contribution to the increases of compressive strength and flexural strength of cement mortar at 28 d. The results of X-ray diffraction (XRD), scanning electron microscope (SEM), and nitrogen (N2) adsorption/desorption tests show that the types of hydration products and crystal grain size did not change after adding MGO. Still, it can help to improve the microstructure of the cement mortar via regulating hydration products and can provide more condensed cores to accelerate hydration. Furthermore, the regulating action of MGO for the microstructure of cement mortar at an early age was better than that at 28 d. 相似文献
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本文主要研究新型外加剂——CTF混凝土增效剂在砂浆中的适宜掺量、与减水剂的适应性及对砂浆重要参数指标的影响。通过合理的配合比设计,试验结果表明,CTF混凝土增效剂对纯水泥砂浆的性能改善作用显著,其适宜掺量为水泥用量的0.6%~0.8%;与同水泥适应性良好减水剂的适应性同样优越,并与聚羧酸系高效减水剂的适应性更好;在不同水灰比和水泥用量的情况下,CTF混凝土增效剂对砂浆流动度及力学性能的影响呈现出一些共同规律。 相似文献
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波浪型钢纤维水泥砂浆吸波性能的研究 总被引:2,自引:0,他引:2
为了适应建筑工程对电磁防护的需要,水泥基吸波材料的研究得到了迅速发展.但水泥作为吸波材料的基材,不仅起胶结材料的作用,其本身的吸波性能也不容忽视.在1~18GHz波段范围内,选用P·Ⅱ42.5R水泥和改性硫铝酸盐水泥(SAC),并掺入6%波浪型钢纤维,制成厚度为10~30 mm的水泥砂浆试样,进行了吸波性能研究.测试结果显示,随试样厚度的增加,吸收峰的位置会向低频区移动;最大吸收率基本都在16 dB左右,6 dB平均累计带宽约5.5 GHz;试样表面粗糙度变化时,低频率区的吸收率基本不变,而高频率区的吸收率有所波动.波浪型钢纤维对SAC水泥砂浆的吸波性能具有一定的改善作用,6 dB吸收峰累计带宽超过11GHz. 相似文献
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