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1.
以工程实际常用的二灰和集料比为20:80的石灰粉煤灰稳定碎石混合料为研究对象,研究分析细集料含量对二灰碎石混合料的无侧限强度、抗压回弹模量和干缩性能的影响规律。结果表明,当2.36mm以下细集料含量在10%左右时,二灰碎石混合料可取得理想的强度性能和良好的抗收缩性能,即二灰材料替代细集料可以得到性能良好的二灰混合料,并可有效提高其抗水侵蚀能力。  相似文献   

2.
二灰碎石早期强度影响因素的显著性分析   总被引:1,自引:1,他引:0  
采用双因素方差分析的试验方法,研究了细集料含量和二灰比例双因素对二灰碎石混合料早期强度影响的变化规律,对其显性进行了分析,结果表明,细集料含量对二灰碎石混合料早期抗压强度有显影响,并随龄期的增长影响更为显。  相似文献   

3.
水泥粉煤灰稳定碎石路面的水泥与粉煤灰比例   总被引:3,自引:2,他引:3  
为了研究水泥粉煤灰稳定碎石混合料中水泥与粉煤灰的最优比例,通过集料含量和级配不变,只改变水泥与粉煤灰比例的方法,研究了不同配合比混合料强度指标随龄期的变化规律。结果表明:混合料不同龄期的强度更多地取决于水泥剂量,而非水泥与粉煤灰比例;180d龄期与28d龄期的强度比值R180/R28能够反映水泥与粉煤灰比例的优劣;R180/R28随水泥/粉煤灰变化曲线的拐点对应水泥与粉煤灰的最优比例。  相似文献   

4.
石灰-粉煤灰-普通硅酸盐水泥稳定碎石是一种常用的路面基层材料,但其早期强度较低,用作路面的维修养护材料时不能快速开放交通.为提高稳定碎石的早期强度,将其中的普通硅酸盐水泥用等质量的硫铝酸盐水泥替换,通过无侧限抗压强度试验(UCT)和劈裂拉伸强度试验(STS)对比了两种不同水泥综合稳定碎石的无侧限抗压强度(UCS)和劈裂拉伸强度(STS),并对无机结合料掺量、水泥掺量及级配对稳定碎石强度的影响开展了试验研究.结果表明,稳定碎石的UCS和STS随水泥含量的增加、养护龄期的增长而增大;养护龄期1 d的石灰-粉煤灰-硫铝酸盐水泥稳定碎石的UCS可达2.28 MPa,达到了路面基层开放交通的规定,且后期强度没有出现降低.论文为路面基层的快速维修养护提供了一种新材料.  相似文献   

5.
采用Matlab软件进行了3种粒级的混凝土再生集料复合料的级配设计,通过试验研究了石灰粉煤灰结合料掺量、结合料中石灰与粉煤灰的比例等参数对石灰粉煤灰稳定再生集料混合料的最大干密度、最佳含水量、7 d无侧限抗压强度、28 d劈裂强度、90 d冲刷质量损失等性能的影响,得到了石灰-粉煤灰比例与混合料7 d无侧限抗压强度的关系式,以及石灰粉煤灰稳定再生集料混合料的最优配合比.在此基础上,进行了该最优配合比石灰粉煤灰稳定再生集料的抗冻融试验研究.结果表明,该最优配合比的石灰粉煤灰稳定再生集料是一种力学性能良好的路面基层材料,可用于二级及二级以下等级公路工程.  相似文献   

6.
水泥粉煤灰稳定碎石配合比设计   总被引:5,自引:0,他引:5  
通过强度、干缩和冲刷试验,研究了水泥粉煤灰稳定碎石混合料的组成结构对混合料强度的影响,水泥质量分数与粉煤灰质量分数的最优比例,水泥质量分数及结合料总质量分数对混合料干缩和冲刷性能的影响。提出了混合料配合比设计方法:首先测试低质量分数水泥7d龄期抗压强度,以确定混合料的最优集料质量分数;接着以后期抗压强度增幅指标(180d/28d)确定水泥质量分数与粉煤灰质量分数的最优比例;最后从抗冲刷和抗干缩性能考虑,前两步选定的配合比水泥质量分数应控制在3%-5%之间,结合料总质量分数不应超过25%。  相似文献   

7.
石灰—粉煤灰稳定碎石基层的物理力学性能   总被引:4,自引:0,他引:4  
利用单粒级和连续配的两种集料配制石灰-粉煤灰碎石。在不同集料情况下,分析比较两种石灰-粉煤灰碎石强度的形成以及强度和模量的发展规律,并就几种路面基层材料的耐久性进行了对比试验,认为石灰-煤粉灰碎石具有较好的耐久性能,采用连续级配集料配制的石灰-粉煤灰碎石具有较优的力学和耐久性能。  相似文献   

8.
水泥粉煤灰稳定碎石强度增长特性   总被引:1,自引:2,他引:1  
为了评价水泥粉煤灰稳定碎石强度增长特性,通过不同龄期无侧限抗压强度试验和劈裂试验,研究了不同粉煤灰掺量下水泥粉煤灰稳定碎石强度变化情况.结果表明:粉煤灰的掺入,对水泥稳定碎石早期抗压强度和劈裂强度都有影响,掺量越大早期强度越低;掺加粉煤灰对长期强度有利,就提高长期强度而言,粉煤灰最佳掺量约为10%;由于7d抗压强度不足以反映掺粉煤灰的水泥稳定碎石强度特性.建议采用7~90 d强度增长率作为评价其强度潜能,在实际工程中应适当降低其7 d强度要求.  相似文献   

9.
二灰碎石基层材料的合理结合料质量分数   总被引:2,自引:0,他引:2  
在二灰碎石最优级配的基础上,根据集料不同密实状态下的空隙率变化结合料的体积分数,通过力学性能、干缩、温缩性能试验,研究结合料质量分数的变化对路用性能的影响,并运用灰色关联决策对不同结合料质量分数下二灰碎石路用性能进行了综合评定。结果表明:当石灰与粉煤灰的质量分数达到21.5%时,二灰碎石28d抗压强度、劈裂强度和抗压模量达到最大值;二灰碎石7d龄期的干缩应变随着结合料质量分数的减少而减小;二灰碎石7d龄期的总平均温缩系数(60℃~-30℃)和低温平均温缩系数(10℃~-30℃)随着结合料质量分数的减少而减小,而高温平均温缩系数(60℃~10℃)呈增大趋势;二灰结合料存在一个最佳体积分数,即当二灰结合料的体积分数等于集料的松散状态下空隙率时,其路用综合性能才能达到最优。  相似文献   

10.
为揭示振动搅拌技术对水泥稳定碎石强度的影响及作用机理,进行了基于传统搅拌和振动搅拌技术的水泥稳定碎石无侧限抗压强度和间接拉伸强度试验,并开展了扫描电镜下的细观作用机理分析.结果 表明:振动搅拌技术可提高水泥稳定碎石的无侧限抗压强度和间接抗拉强度,降低变异系数,提高均匀性,缩短强度稳定时间,对低水泥剂量下强度的改善效果更明显;在龄期为7,28 d时,振动搅拌水泥稳定碎石的水化物明显较多,且分布更均匀,在混合料内部形成了大量韧性较好的网状结构,有利于提高强度;在龄期为90 d时,钙矾石晶体成柱状并嵌入集料内部,使结构更致密,强度更高.  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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