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近几年来粉煤灰在建材、建筑行业得到广泛利用,我站也频繁地接受粉煤灰的委托试验,但在试验中笔者发现粉煤灰中SO3含量的测定方法有必要进行进一步探讨. 相似文献
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近几年来粉煤灰在建材、建筑行业得到广泛利用,我站也频繁地接受粉煤灰的委托试验,但在试验中笔者发现粉煤灰中SO_3含量的测定方法有必要进行进一步探讨。 相似文献
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烧胀粉煤灰陶粒课题,是由原建材部和陕西省科委下达给我所的一项研制任务。经过几年努力,已完成了研制任务,并于1985年7月通过省级技术鉴定。现将有关研制情况介绍如下:(一)粉煤灰的烧胀性能及改善途径1.粉煤灰的烧胀性能为了更好地了解粉煤灰的膨胀性能及掌握影响膨胀性能的因素,我们对22个省市的40家电厂的粉煤灰的化学组成及膨胀性能作了检验 相似文献
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粉煤灰在商品砼中的应用,在发达国家中较为普遍,在我国也不是新鲜事,北京市也有单位应用。但是,相对普遍应用来说,可说本市还是刚刚起步。本市现有的搅拌站中,已有的搅拌机多数不带有粉煤灰装置系统,我站的搅拌机就是这样的。我们根据国家经委和北京市经委《关于 相似文献
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研究采用工业废弃物粉煤灰为原料,辅以粉煤灰激发剂,在实验室研究粉煤灰的最佳配比。通过研究发现,在碱性条件下使用强酸盐作为活性激发剂以及使用经过机械粉磨的粉煤灰制造而成的粉煤灰小型空心砌块,经过配方的调整与优化,使砌块中粉煤灰的掺量高,砌块的性能同样能满足标准的要求。 相似文献
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垃圾焚烧飞灰因极高的重金属含量而被认为是一种危险废弃物,但与火山灰成分的相似使该材料有着资源化利用的潜在价值。以飞灰及其螯合物为研究对象,探讨了含水率、养护条件等因素对材料应力应变及环境特性的影响。研究结果表明:飞灰螯合物重金属浸出浓度较低,并有着较强的吸水特性;飞灰及其螯合物强度早期随着养护时间的增长呈上升趋势,破坏应变随之减小,脆性不断增大;材料强度在中后期出现明显分化,飞灰(90%湿度养护)强度约为螯合飞灰的23.11倍。飞灰强度随含水率的增大而减小,可归结于孔隙水对压实能量的吸收和结构的影响;螯合飞灰强度均随养护时间和含水率增加而显著增大。 相似文献
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Cold-bonded fly ash aggregate concrete with fly ash as part of binder or fine aggregate facilitates high volume utilization of fly ash in concrete with minimum energy consumption. This paper investigates the influence of fly ash on strength and sorption behaviour of cold-bonded fly ash aggregate concrete due to partial replacement of cement and also as replacement material for sand. While cement replacement must be restricted based on the compressive strength requirement at desired age, replacement of sand with fly ash appears to be advantageous from early days onwards with higher enhancement in strength and higher utilization of fly ash in mixes of lower cement content. Microstructure of concrete was examined under BSEI mode. Replacement of sand with fly ash is effective in reducing water absorption and sorptivity attributable to the densification of both matrix and matrix–aggregate interfacial bond. Cold-bonded fly ash aggregate concrete with a cement content of 250 kg/m3, results in compressive strength of about 45 MPa, with a total inclusion of around 0.6 m3 of fly ash in unit volume of concrete. 相似文献
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This paper presents the laboratory study on the bearing ratio of unreinforced and reinforced fly ash overlying soft soil beds of a total of 11 fly ash samples collected from different thermal power plants located in the Eastern part of India. The thickness of the bottom clay layer (Hc) was maintained as 100 mm in the bearing ratio mould. The upper layer thickness of compacted fly ash (Hf) was varied. The values of the ratio Hf/Hc used were 0.75, 1.00 and 1.25 in this study. The fly ash layer was reinforced with single layer and double layers of geotextiles. The effects of (i) position and number of layers of geotextiles, (ii) thickness of the compacted fly ash layer overlying soft soil layer, and (iii) moulding water content of the soft soil, on the bearing ratio of fly ash are highlighted. The inclusion of geotextile into the compacted fly ash bed enhances the bearing ratio. An increase in the thickness of compacted fly ash layer over the soft soil layer also increases the bearing ratio of the compacted fly ash bed. The values of unconfined compressive strength and deformation modulus of all the fly ash samples are also presented. Empirical relationships to estimate deformation modulus of fly ash from unconfined compressive strength and relationships between initial tangent modulus and secant modulus of fly ash are presented. It may be concluded from this research study that reinforced compacted fly ash overlying soft soil with a geotextile layer at the interface can find potential application in the construction of roads over soft soil. 相似文献
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《Construction and Building Materials》2007,21(9):1869-1878
The study presented herein provides a new insight into the effects of physical and chemical properties of the fly ash on the characteristics of the cold-bonded fly ash lightweight aggregates. LWAs were manufactured through the cold-bonding pelletization of two fly ashes differing in their physical and chemical properties. Moreover, one type of the LWAs was surface treated by water glass. The produced fly ash aggregates were then examined by means of ESEM micrograph, EDX spectrum, and XRD pattern to resolve the microstructural and the mineralogical characteristics of the LWAs. The findings of the study revealed that the fly ash with higher specific surface and with lower CaO content yielded higher strength LWAs. Furthermore, the surface treatment with water glass provided a marked increase in the aggregate strength and a reduction in the water absorption. The LWCs made with such LWAs had a compressive strength of as high as 60 MPa. 相似文献
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简要阐述了粉煤灰在混凝土中的作用机理,分析了粉煤灰掺入可降低混凝土水化热的原因,阐明了粉煤灰对大体积混凝土所起的作用,从而推广粉煤灰的应用。 相似文献
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再论粉煤灰小型空心砌块 总被引:5,自引:1,他引:5
文章通过分析粉煤灰小型空心砌块胶凝材料结石的矿物组成,认为其并非是粉煤灰混凝土制品.而是粉煤灰硅酸盐混凝土制品。并指出自然养护粉煤灰小型空心砌块与粉煤灰“免烧砖”属同一类产品,不宜发展,并再次建议修订行业标准《粉煤灰小型空心砌块》(JC862--2000)。 相似文献
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粉煤灰在建筑中的应用研究 总被引:2,自引:0,他引:2
综述了粉煤灰在建筑中用于生产粉煤灰水泥、粉煤灰制砖、粉煤灰微晶玻璃等方面的应用,并在此基础上对加强粉煤灰在建筑中的应用提出了几点建议,同时对粉煤灰应用前景作了分析与展望,以提高经济效益和环境社会效益。 相似文献
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为了更全面的了解粉煤灰混凝土,研究了粉煤灰混凝土的防火性能,ANSYS软件模拟表明,粉煤灰混凝土与普通混凝土有相同的热传导性能;高温试验表明,粉煤灰混凝土与普通混凝土的强度降低值的差异不超过0.1%,在防火研究方面可以用粉煤灰混凝土代替普通混凝土。 相似文献