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将磷铝酸盐水泥熟料掺入到硅酸盐水泥中制备的改性硅酸盐水泥具有优异的力学性能.对改性水泥IR图谱中-OH基非对称伸缩振动带进行曲线拟合,并与硅酸盐水泥进行对比,研究了磷铝酸盐水泥对硅酸盐水泥的改性机理.结果表明改性硅酸盐水泥浆体中有5种状态的“水”:Ca-OH,Si (P)-OH,Al-OH/AFt结晶水、氢键水和配位水,其在各水化龄期与Si、Al结合的以OH状态存在的“水”较硅酸盐水泥多,而与Ca结合的以OH状态存在的“水”以及氢键结合的水、配位水较少,从而展现较硅酸盐水泥优异的力学性能. 相似文献
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以铝酸盐水泥熟料、硅酸盐水泥熟料和粉煤灰为原料,探讨了掺加少量铝酸盐水泥熟料对硅酸盐水泥及粉煤灰硅酸盐水泥复合体系水化、凝结和硬化性能的影响。结果表明,在硅酸盐水泥及粉煤灰硅酸盐水泥中掺加铝酸盐水泥熟料,可以明显缩短水泥的初、终凝时间,但复合体系的需水量增加;掺加少量铝酸盐水泥熟料(≤3%)可明显提高硅酸盐水泥的早期强度,但后期强度(28d)有所降低;当铝酸盐水泥熟料的掺量达5%时,水泥的各龄期强度均明显降低。少量铝酸盐水泥熟料掺加到粉煤灰硅酸盐水泥中,复合体系的各龄期强度都明显提高,且早期强度的提高幅度较大。 相似文献
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改性硅酸盐水泥的水化动力学研究 总被引:2,自引:0,他引:2
将磷铝酸盐水泥熟料掺入到硅酸盐水泥中制备改性水泥,从水化动力学的角度研究其水化情况,并与硅酸盐水泥的相应行为进行了对比.首先通过测定水化放热速率、新拌水泥浆体中的Ca2+和SiO44-离子浓度、电导率及pH值研究了改性硅酸盐水泥的水化历程,并求得了水化动力学方程.其次,测定了改性硅酸盐水泥的净浆与砂浆的强度,并用XRD等分析方法初步探讨论了改性水泥的水化机理.研究发现,改性硅酸盐水泥的水化历程与硅酸盐水泥相似,也经历初始期、诱导期、加速期、减速期和稳定期,但水化放热速率明显提高;在加速期,两者的水化反应均主要由自动催化反应控制,在减速期,均主要由扩散过程控制,但反应速率常数前者明显高于后者.无论是砂浆强度,还是净浆强度,前者也均高于后者,且凝结时间相对缩短.XRD图谱显示,前者的C3S/C2S衍射峰强度的降低率高于相应龄期的硅酸盐水泥.上述结果均意味着改性硅酸盐水泥的水化速度明显高于硅酸盐水泥;水化加速的机理为磷铝酸盐熟料水化吸收了水化浆体中OH-离子,使水化体系的OH-离子浓度减少,从而加速了C3S、C2S的水化反应. 相似文献
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阿利特—硫铝酸盐水泥与硅酸盐水泥复合性能的研究 总被引:10,自引:1,他引:10
研究了阿利特-硫铝酸盐水泥与硅酸盐水泥复合所制备的水泥的性能。结果表明,复合后水泥的强度性能优于单一品种水泥的性能;凝结时间则由复合体中占比例较多的一种水泥所控制。 相似文献
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A. Amin H. H. M. Darweesh A. M. Ramadan S. M. M. Morsi M. M. H. Ayoub 《应用聚合物科学杂志》2011,121(1):309-320
Hyperbranched polyesteramides (HBPA1 and HBPA2) were synthesized by the bulk polycondensation of maleic anhydride (MAn) as an A2 monomer with both of diisopropanolamine (DIPA) and diethanolamine (DEA), respectively, as B′B2 monomer. The prepared polymers were analyzed with IR, GPC, 1H NMR, TGA, and DSC. The hyperbranched polyesteramides were applied as polymeric admixtures in two different types of cement, namely ordinary Portland cement (OPC) and Portland limestone cement (PLC). Several parameters were studied to evaluate the action of HBPA1 and HBPA2 polymers as cement admixtures. Adding HBPA1 and HBPA2 decreased the water of consistency and increased the compressive strength with no effect on the chemical composition of the cement phases. The combined water content and bulk density displayed the same trend as compressive strength. The IR spectra of the formed phases for the mixed cement pastes with HBPA1 and HBPA2 illustrated increased intensities of the absorption bands than those of the pristine cement pastes. The SEM photos showed that the incorporation of HBPA1 and HBPA2 in cement phases affected the morphology and microstructure of the formed hydrates. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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Hyperbranched polyesteramides (HB1 and HB2) were prepared by the bulk reaction between phthalic anhydride (PhAn) with either diisopropanolamine (DiPA) or diethanolamine (DEA), respectively. The hyperbranched polyesteramides were characterized by IR, GPC, 1H‐NMR, and thermal analysis (TGA and DSC). The effects of solutions of 1, 3, and 5 wt % HB1 and HB2 on the properties of Ordinary Portland Cement (OPC) and Portland Limestone Cement (PLC) were studied. Measurements of water of consistency, setting times, bulk density, apparent porosity, and compressive strength for the cement pastes were performed. Some selected cement pastes were characterized by IR and SEM photos. The results showed that HB1 and HB2 slightly increased the compressive strength, the combined water and density while decreased the apparent porosity. IR of the formed phases showed increase in the intensities of the spectra for the cement pastes mixed with HB1 and HB2 when compared with those of the blank cement pastes. SEM images showed that the incorporation of HB1 and HB2 affected only shape or morphology and crystallinity of the formed hydrates. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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低成本、绿色水泥是在硅酸盐水泥熟料矿物中引入硫铝酸钙(C4A3S)而发展起来的,它同时具有硅酸盐水泥和硫铝酸盐水泥的优良特点,对于配制高强,高温合材掺量的硅酸盐水泥具有明显的优势,本文介绍了低成本、绿色水泥生产技术及生产实践中所取得的效益,从理论和实践方面都证明了它是一项成熟、先进适用的生产技术。 相似文献
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Linear relationships between free chloride and total chloride contents in concrete are proposed based on the results of several long-term exposure tests under marine environment for various cements, such as ordinary portland cement (OPC), high early strength portland cement (HES), moderate heat portland cement (MH), calcium aluminate cement (AL), slag cements of Types A (SCA) and B (SCB), and fly ash cement of Type B (FACB). A high chloride-binding ability is found for AL as compared to the other cements. Replacing the OPC with slag reduces the chloride-binding ability. The proposed linear relationships show reasonably good agreement with field data obtained from the wharf structures. 相似文献
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为了解硅酸盐水泥与硫铝酸盐水泥复合之后性能变化的原因,通过对复合水泥孔隙溶液的pH值进行研究,探讨了pH值变化与性能之间的内在联系。研究表明,孔隙溶液pH值变化与强度有良好相关性,水化3h后复合水泥pH值在SAC掺量为20%-80%之间出现波谷,水化剧烈并开始大量放热,后期强度也出现明显波谷区,其中以其掺量为60%时pH值和后期强度最低;当SAC或PC掺量为0%-20%时,复合水泥孔隙溶液pH值和强度相对于纯的SAC或PC而言基本没有变化,甚至还会稍微提高,这对降低水泥生产成本和提升水泥性能具有积极意义。 相似文献
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对如何提高我国通用水泥质量的探讨(一)--我国水泥质量存在的主要问题 总被引:9,自引:4,他引:5
我国水泥质量民国际先进水平比较,主要关屡高标号水泥数量少,最高强度比较低;水泥早期强度相对值和绝对值都是低;没有控制水泥的及各组分的颗粒级配;还没能按混凝土工艺要求及时生产和供应最佳性能和足够数量的均质水泥。提高我国水泥质量的根本途径是产质量,耒泥性能,包括提高硅酸盐矿物总量和早强矿物含量,提高熟料率值,特别是提高SM,增加细粉含量,控制水泥颗粒级配,以及走掺矿渣和粉煤灰抑制碱集料反应的道路。 相似文献