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1.
配制了由减水剂、盐类组成的NY-2复合激发剂,并将期掺入由425R水泥和粘土混合而成的火山灰水泥中。实验结果表明,当粘土掺量为30%时,掺加0.8% ̄1.2%的NY-2复合激发剂,可以在提高水泥早、后期强度的同时,改善水泥流动性,调整水泥凝结时间并保持火山灰水泥的其他特性。应用该复合外加剂可取得较好的经济效益。  相似文献   

2.
《河南科学》2016,(6):910-916
掺碱激发剂火山灰-水泥既可以有效利用火山灰和保护环境,又可以改善火山灰-水泥胶凝材料的性能.选用掺合料为火山灰,变换不同含量的碱激发剂(氢氧化钠与水玻璃),测定龄期为7、28、90 d时混凝土的力学性能,确定最佳组合,并进行电镜试验,观察微观结构.研究结果表明:掺碱激发剂会使胶凝材料的强度随碱掺量的变化而变化,掺氢氧化钠的早期强度要优于掺水玻璃的早期强度,而后期掺水玻璃的强度要比掺氢氧化钠的强度发展得好.  相似文献   

3.
煤矸石水泥复合体系强度的化学激发   总被引:1,自引:0,他引:1  
以正交设计实验法研究了Ca(OH)2、CaSO4.2H2O和NaOH等激发剂对煤矸石水泥复合体系早期强度的影响。结果表明:加入激发剂可以大幅度地提高煤矸石水泥复合体系的3天、7天早期强度;适当掺量的激发剂对复合体系的后期强度也有促进作用。依据实验结果,最佳的Ca(OH)2、CaSO4.2H2O和NaOH激发剂掺量分别为2.5%,4.0%,0.5%。另外,对激发剂对体系强度影响的机理进行了探讨。  相似文献   

4.
为了克服矿渣水泥稳定碎石基层早期强度不足的问题,选择氢氧化钠与硅酸钠两种碱性激发剂对矿渣水泥的活性进行激发,根据单掺试验结果掺配出一种复合碱激发剂,并研究了该复合碱激发剂对水稳碎石基层无侧限抗压强度、劈裂强度、抗弯拉强度、抗压回弹模量及干缩性能的影响。试验结果表明,掺入氢氧化钠或硅酸钠均能有效激发矿渣水泥的活性,二者的合理掺量分别为6%与4%,按此合理掺量复配而成的复合碱激发剂具有比单掺更优异的效果;该复合碱激发剂较好地提高了基层试块的无侧限抗压强度、劈裂强度、抗弯拉强度、抗压回弹模量,但对干缩性能产生了不利影响。  相似文献   

5.
以钢渣、粉煤灰、水泥熟料为主要原料,并掺入少量激发剂,制备高混合材掺量高强复合水泥.研究钢渣细度、水泥的复合组分比例及激发剂对钢渣粉煤灰复合水泥性能的影响,并通过SEM、XRD分析激发剂对复合水泥水化性能的影响.结果表明:钢渣比表面积在310m2/kg以上时,钢渣具有较好的活性.激发剂可进一步增大钢渣、粉煤灰的水化活性,加快复合水泥的水化速度,从而提高水泥的力学性能,缩短水泥的凝结时间,但激发剂对复合水泥水化产物种类影响不大.  相似文献   

6.
镁渣和矿渣对复合水泥性能的影响   总被引:1,自引:0,他引:1  
掺加10%~40%镁渣制备了镁渣矿渣复合硅酸盐水泥,研究了镁渣对复合水泥物理性能的影响规律。结果表明:镁渣中主要矿物是β-C2S和γ-C2S,具有较好的火山灰活性。随着镁渣矿渣比(MS/BS)的增加,复合水泥凝结时间延长,强度逐渐下降,当MS/BS为0.67时,即镁渣掺量20%,矿渣掺量30%时复合水泥28d抗折强度达9.10MPa,抗压强度达42.53MPa,达到了国标42.5#复合硅酸盐水泥要求。  相似文献   

7.
煤矸石的热力-化学复合活化研究   总被引:2,自引:0,他引:2  
采用不同温度下的煅烧和添加化学激发物质的复合活化方法对煤矸石用作高性能水泥辅助性胶凝材料时潜在活性激发效果进行了实验探讨。实验结果表明,原始煤矸石未经任何处理直接用作水泥混合材时基本上不表现出火山灰活性,会导致水泥强度大幅度降低。煤矸石经600~900℃加热处理之后再与水泥混合使用,表现出显著的火山灰活性,水泥强度得到明显改善。用芒硝或水玻璃作为激发荆对煤矸石施加热力-化学复合活化,在适宜的掺量范围内水泥强度,尤其是早期强度,得到进一步改善。采用水玻璃的场合活化效果优于采用芒硝的场合。煤矸石热力一化学复合活化的适应范围为热处理温度600~800℃,水玻璃掺量不超过4%。  相似文献   

8.
矿渣和层硅-Na_2SO_4复合激发剂对磷渣水泥力学性能的影响   总被引:1,自引:0,他引:1  
分别研究矿渣和层硅-Na2SO4复合激发剂对磷渣水泥力学性能的影响,用扫描电镜(SEM)以及X射线衍射(XRD)等方法对磷渣及磷渣水泥性能进行表征.结果表明:矿渣以不同比例掺入磷渣水泥体系中可以一定程度提高磷渣水泥强度,且在磷渣掺量较大的情况下,这种矿渣增长效应更加显著,平均增长率可超过15%.在磷渣水泥体系中掺入适量的层硅-Na2SO4复合激发剂,在高磷渣掺量(60%)条件下,28 d抗压强度提高了5.6 MPa.  相似文献   

9.
探讨了化学激发剂Na2CO3对高掺量矿渣水泥的力学及耐久性能的影响。研究结果证明:在矿渣掺量达70%的情况下,以1.5%Na2CO3作为激发剂可显著改善高掺量矿渣水泥的力学性能,28 d的抗折强度提高了25%,且该高掺量矿渣水泥的耐久性能如安定性、水化热、抗硫酸盐腐蚀均优于纯硅酸盐水泥。  相似文献   

10.
采用掺入30%,50%粉煤灰的水泥胶砂强度试验,研究了CaCl2和CaSO4.2H2O两种激发剂在单掺、复掺时对粉煤灰活性的激发效果。在试验范围内,CaCl2单掺对30%,50%粉煤灰水泥胶砂体系的粉煤灰激发效果显著;CaSO4·2H2O的单掺对30%粉煤灰激发效果随掺量呈非线性关系,早期强度的激发效果相对明显,掺入量为1.5%时,效果最佳。复掺时粉煤灰活性的激发均高于单掺激发,30%掺量粉煤灰复掺编号F2的粉煤灰水泥体系胶砂早期强度提高最为显著,50%掺量粉煤灰复掺编号F4的整体激发效果最佳。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

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