巷道底板泥岩泥化物固化体的力学性能

为避免煤矿巷道底板泥岩泥化物清淤抛弃产生的环境污染问题,提出了将泥岩泥化物快速固化后作为巷道路面基层材料的处理方法,并为此研制了一种高效固化剂.通过不同固化剂掺量、不同养护龄期泥岩泥化物固化体的无侧限抗压试验,对该固化体的强度与变形规律进行了研究.研究结果表明:对于掺15.0%(质量分数)固化剂的泥岩泥化物固化体,其3 d无侧限抗压强度可达28 d的85%,即该固化体具有十分明显的快硬早强特性,可以作为巷道路面的基层材料;最低固化剂掺量与龄期相关,并与龄期呈对数关系,与固化系数呈线性关系.     

抗裂纤维加固泥岩泥化物固化体试验研究

针对某矿区掘进巷道的底板泥岩泥化物,研制了一种高效固化剂,将该固化剂和聚丙烯抗裂纤维用于泥岩泥化物的加固工程中.通过正交试验,研究了纤维固化体的抗压强度、弹性模量、破坏应变与纤维固化体配比之间的关系.研究表明,泥岩泥化物纤维固化体具有较好的强度与抗变形特性,可作为巷道路面的基层材料.     

水泥混凝土路面病害及处理

随着水泥混凝土路面建设的迅速发展 ,出现了大量的公路病害。分析了产生裂缝、板角断裂、沉陷、拱起、错台、唧泥、坑洞、剥落、露骨、麻面、磨损等公路病害的原因 ,并提出了防治这些病害的措施和一些采用的新材料和新工艺 ,如 :磷石膏石灰粉煤灰稳定锰渣 (6 %磷石膏、8%石灰、16 %粉煤灰、70 %锰渣 ) ,其 7d无侧限抗压强度达到 1.6 1MPa,可作为高速以及一级公路基层材料 ;MG聚合物早强微膨胀水泥砂浆可进行罩面快速修补材料 ,该修补方法完工 1d后就可开放交通等 ,这些对水泥混凝土路面的施工、养护和水泥混凝土路面病害处理具有一定的参考意义     

石灰干化污泥应用于道路基层的研究

为实现石灰干化污泥的再生利用,以干化污泥作为路面基层材料为主要应用研究对象,在充分利用干化污泥中石灰活性的条件下,分别配制了干化污泥稳定土、干化污泥石灰稳定土、干化污泥水泥稳定土和干化污泥粉煤灰稳定土,并以其无侧限抗压强度为主控指标,通过干化污泥与土、石灰、水泥、粉煤灰按照不同比例混合配制混合料的强度对比,进行了配合比优化。试验结果表明:经配合比优化,利用石灰干化污泥配制的稳定土强度可以满足道路基层材料要求。     

石灰掺量对粉煤灰石灰桩性能的影响

本文分析了试验所用原材料的化学成分 ,研究了不同配合比粉煤灰石灰桩的无侧限抗压强度 ,探讨了石灰掺量对粉煤灰石灰桩无侧限抗压强度的影响 ,为工程中合理使用粉煤灰石灰桩提供依据。     

固化粉煤灰抗压强度试验及固化机理研究

将具有优异性能的固化剂作为外掺剂应用于粉煤灰的固化研究。通过室内无侧限抗压强度试验,探讨了固化剂掺入比和龄期对固化粉煤灰强度的影响规律;通过固化粉煤灰X射线衍射（XRD）试验,研究了固化粉煤灰各组分在强度形成过程中的变化规律;通过扫描电镜（SEM）测试,分析了固化粉煤灰的微结构特点及微结构形成过程;在分析粉煤灰-石灰体系反应基本原理的基础上,提出了固化粉煤灰的固化机理,该研究将为固化粉煤灰在工程中的进一步应用奠定理论和试验基础。     

河道清淤底泥固化材料正交试验研究

介绍了河道底泥常用的固化方法,通过无侧限抗压强度的正交试验,研究了水泥、粉煤灰、生石灰、沸石对固化底泥强度的影响规律,试验结果表明,掺入水泥、粉煤灰、生石灰、沸石后,固化底泥的强度得到明显改善,在四种固化剂中,水泥对固化土抗压强度的影响处于主导地位,粉煤灰次之,生石灰和沸石最小。     

石灰粉煤灰稳定黄土的无侧限抗压强度研究

以石灰粉煤灰稳定黄土为对象,通过标准击实试验、无侧限抗压强度试验,研究养护龄期和石灰粉煤灰掺量对稳定黄土最佳含水率、最大干密度及无侧限抗压强度的影响。结果表明,随石灰粉煤灰掺量的增加,稳定黄土最佳含水率增大,最大干密度减小;石灰粉煤灰掺量一定时,随粉煤灰掺量的增加,最大干密度增大,最佳含水率减小;无侧限抗压强度随养护龄期的增长、石灰粉煤灰掺量的增加而增大。通过对试验数据的拟合回归,建立了稳定黄土无侧限抗压强度与孔隙率、粉煤灰与石灰的比值（F/L）及石灰粉煤灰总体积掺量的关系。     

基于响应面法的固化泥浆强度试验研究

试验选用水泥、粉煤灰、生石灰和硅酸钠作为泥浆的固化材料,即以水泥、粉煤灰、生石灰、硅酸钠作为四个影响因子,以28 d的无侧限抗压强度为响应值。采用Box-Behnken响应面试验设计方法安排试验。通过方差分析排除不显著项,建立二次多项式回归方程,并分析各影响因子间的交互关系。结果显示:水泥、生石灰对固化泥浆抗压强度的线性作用显著;粉煤灰在一定掺量条件下可以以1∶1的比例代替水泥对泥浆进行固化。生石灰掺量不宜过高,否则会影响水泥对泥浆的固化作用。生石灰作为粉煤灰的碱性激发剂,对提升粉煤灰的固化作用效果显著。     

复合方法改良膨胀土无侧限抗压强度试验研究

本文以改良膨胀土标准养护7 d的无侧限抗压强度为研究对象,分别在膨胀土中掺入水泥、石灰、粉煤灰、风化砂来进行单一方法改良,测试其无侧限抗压强度;在膨胀土中分别掺入水泥和风化砂、石灰和风化砂、粉煤灰和风化砂来进行复合方法改良,进行无侧限抗压强度试验。试验结果表明,在膨胀土中分别单一掺入水泥、石灰、粉煤灰、风化砂均能有效提高改良膨胀土的无侧限抗压强度,而且石灰、粉煤灰、风化砂的掺入量均有一个最佳值,使改良膨胀土的无侧限抗压强度达到最大值,从提高膨胀土无侧限抗压强度的角度来讲,单一方法改良的效果由好到差依次是水泥、石灰、风化砂、粉煤灰。而在膨胀土中分别掺入水泥和风化砂、石灰和风化砂、粉煤灰和风化砂来进行复合方法改良,无侧限抗压强度值均有了大幅度的提升,从提高无侧限抗压强度的角度来看,水泥和风化砂复合改良的效果要优于石灰和风化砂复合改良的效果,粉煤灰和风化砂复合改良的效果最差。通过复合改良方法与单一改良方法对比,可以发现,在相同条件下,复合改良方法的无侧限抗压强度值要比单一改良方法大得多,复合改良方法要大大优于单一改良方法。     

Unconfined compressive strength of fly ash reinforced with jute geotextiles

A series of unconfined compressive strength (UCS) tests have been conducted on unreinforced fly ash as well as fly ash reinforced with jute geotextiles. The effects of different governing parameters viz., degree of saturation, size of samples, number of jute geotextile layers and age of sample on UCS have been studied. From the test results it is found that the values of UCS are maximum at degree of saturation of 70–75%. The effect of sample size on the values of UCS for unreinforced fly ash is insignificant, whereas with increase in diameter of sample, values of UCS increase in case of reinforced fly ash. With increase in number of jute geotextile layers for reinforced fly ash samples, values of UCS increase and maximum enhancement is found to be around 525% with 4 layers of reinforcement. A non-linear power model has been developed to estimate unconfined compressive strength (UCS_R) of fly ash reinforced with jute geotextiles in terms of unconfined compressive strength (UCS_UR) of unreinforced fly ash and number of layers of reinforcement (N).     

水泥粉煤灰稳定碎石钢渣混合料作为基层配合比的研究

本文以钢渣为原料,通过室内试验对水泥粉煤灰稳定碎石钢渣作为高等级公路路面基层的性能进行了分析,得到不同配比下水泥粉煤灰稳定碎石钢渣混合料的最大密度和最佳含水量,以及7d无侧限抗压强度,为水泥粉煤灰稳定碎石钢渣用于高等级公路基层提供了技术依据。     

Study on lime–fly ash–phosphogypsum binder

In this study a new type of lime–fly ash–phosphogypsum binder was prepared to improve the performances of lime–fly ash binder which was a typical semi-rigid road base material binder in China. The modified lime powder had much higher activity than ordinary quick lime or slaked lime powder, it was the best alkali activator to prepare lime–fly ash–phosphogypsum binder. The optimum formulation of this binder was consisted of 8–12% modified lime, 18–23% phosphogypsum and 65–74% fly ash. The parallel experiments shown that lime–fly ash–phosphogypsum binder had higher strength than ordinary lime, cement, and lime–fly ash stabilized soils road base materials, granular soils stabilized with this binder had higher later strength than that of lime–fly ash or cement stabilizing granular soil, it had higher early strength and steady strength development. The phosphogypsum hastened the pozzuolana reactions between the lime and fly ash, it reacted with lime and fly ash also, this reaction formed some AFt and the formation of AFt brought on a slight expansivity which could compensate the shrinkage of the binder. The pore structure of this binder was finer than that of the lime–fly ash, so the strength and performances of the road base material stabilized with lime–phosphogypsum–fly ash binder was much higher than those of the lime–fly ash road base material.     

Parameters Controlling Strength of Industrial Waste-Lime Amended Soil

Unconfined compression tests and suction measurements were carried out in the present work on sandy specimens with distinct Class F fly ash amounts, lime contents, porosities and curing periods to assess key parameters controlling strength of fly ash-lime amended soil. A special effort has been allocated in order to develop a dosage methodology for fly ash-lime improved soils based in a rational criterion, as it exists in the concrete technology where the water/cement ratio plays a fundamental role in the assessment of the target strength. The results show that the unconfined compressive strength (UCS) increased linearly with the amount of lime for soil-fly ash-lime mixtures at all curing time periods studied. A power function fits better the relation UCS-porosity for soil-fly ash-lime mixtures. The bigger the amount of fly ash and the curing time, the larger the UCS for any given porosity and lime content. Finally, the porosity/volumetric lime content ratio, in which volumetric lime content is adjusted by a coefficient (in this case a unique value-0.12-was found for all soil-fly ash-lime mixtures and all curing periods studied) to end in single correlations for each curing period, show to be a good parameter in the evaluation of the unconfined compressive strength of the soil studied (UCS varies non-linearly with the porosity/volumetric lime content ratio in the case of fly ash-lime addition).     

粉煤灰炉渣加固土的室内无侧限抗压强度试验研究(英文)

给出了用粉煤灰、炉渣等工业废料加固土的室内无侧限抗压强度试验结果,分析了加固土无侧限抗压强度与外加剂掺量、养护龄期之间的影响规律,得出了针对不同工业废料加固土所用外加剂的最佳掺量。     

Potential use of stockpiled circulating fluidized bed combustion ashes in manufacturing compressed earth bricks

There is currently 123 million tons of coal combustion by-products produced in US each year. Among these include fly ash, bottom ash, boiler slag, and flue gas desulphurization material. Of that approximately 40% are utilized as a construction material in cement manufacturing, roadway construction, and others. However, the utilization of some ashes such as those produced by fluidized bed combustion has been limited due to their inherent high sulfate and carbon content. This paper is aimed at the evaluation of the potential use of stockpiled circulating fluidized bed combustion ash (SCFBCA) to develop compressed earth brick (CEB). Laboratory tests were conducted to determine the physical, chemical, and mineralogical properties with respect to SCFBCA. A series of tests were carried out to evaluate the properties of the bricks related to filler and binder types on compressive strength, density, and absorption. Test results indicate that SCFBCA can be used to manufacture CEB. Subordinately, test results may provide a means to reduce a waste disposal problem while providing the brick industry with a new, useful, low cost raw material.     

Experimental study of the influence of water and temperature on the mechanical behavior of mudstone and sandstone

Understanding the influence of water and temperature on the mechanical behaviors of coal measure rocks is important for deep coal resource exploitation. Using an electro-hydraulic servo-controlled testing system (MTS816) with a self-designed thermostatic water tank, a series of water absorption experiments and uniaxial compression experiments were performed on mudstone and sandstone samples that were immersed in water under different temperature conditions (from 25 to 95 °C). The water absorption characteristics at different temperatures and the effect of water and temperature on the mechanical strength, deformation and failure mode of the samples under uniaxial compression were systematically analyzed. In addition, computerized tomography (CT) scanning was used to examine the microstructural changes in the mudstone and sandstone before and after water saturation at different water temperatures. The results from the water absorption tests show that the water content of the mudstone and sandstone samples kept increasing with immersion time until a saturated state was reached, with the trend generally following an exponential law. The higher water temperature allowed additional water absorption in the saturated mudstone, but less water absorption in the saturated sandstone. The mechanical tests suggest that the presence of water can significantly reduce the mechanical properties of the coal measure rocks. Decreases in the uniaxial compressive strength (UCS) of 76.0 and 38.9 % and the elastic modulus of 68.1 and 48.5 % were observed in the mudstone and sandstone, respectively, because of water saturation at room temperature. Moreover, the water-weakening effect was sensitive to water temperature, and as the water temperature increased from 25 to 95 °C, the UCS and elastic modulus decreased linearly in the saturated mudstone by 53.8 and 70.4 %, respectively, and increased linearly in the saturated sandstone by 21.3 and 20.2 %, respectively. The increasing water temperature also promoted a transition in the saturated mudstone from brittle to ductile behavior, but it had a negligible effect on the failure mode of the saturated sandstone. The CT scanning tests demonstrated that new fractures are produced inside the mudstone after water saturation and that the increasing temperature can exacerbate such water-induced damage. However, no obvious fractures were observed in the CT images of the sandstone at room temperature or at high water temperatures, and the water-induced damage in the sandstone appeared as the micro-fractures at a scale below the CT resolution.     

C60高性能混凝土配合比设计及其性能试验研究

利用粉煤灰、高效减水剂配制出了C60高性能混凝土。当粉煤灰掺量为16%,高效减水剂掺量为1.0%,高性能混凝土28d强度高达77.3MPa,CI-扩散系数低至1.52×10~(-9)cm~2/s,1m~3混凝土节省水泥约200kg。本课题即C60高性能混凝土的配制试验,为今后高性能混凝土在实际中的应用打下良好的基础。     

粉煤灰水泥稳定碎石在场道工程中的应用

以粉煤灰在海口美兰机场场道基层施工中的利用为示例，详细阐述了粉煤灰用于水泥稳定碎石基层时配合比的设计与确定，力学性能的变化与对,比以及混合料拌和和施工控制措施等，并就粉煤灰在水泥稳定碎石基层中的应用作了评价。