木质素聚合物改性粉煤灰混凝土性能的试验研究

以高沸醇溶剂法制备木质素,并经化学处理获得木质素磺酸钙作为减水剂改性粉煤灰混凝土:通过粉煤灰混凝土配比的设计,对试验数据进行了研究与分析.试验证明,通过自制的木质素聚合物改性粉煤灰混凝土,对其性能具有一定的影响.     

粉煤灰资源化及综合利用可持续发展的研究

指出了随着时代的发展,粉煤灰的利用越来越广泛,但随之出现的问题也越来越多,当时人们还没有可持续发展的观念,粉煤灰的综合利用没有形成规模,且技术落后,产品并没有达到预期效果。提出了粉煤灰资源化是粉煤灰综合利用的前提条件,生产高附加值产品是粉煤灰综合利用的重要方向,最终要实现粉煤灰综合利用的可持续发展。     

高钙粉煤灰/水泥刨花板制备及性能

研究了利用高钙粉煤灰代替部分水泥制作粉煤灰/水泥刨花板,探讨了粉煤灰替代量、激活剂、木刨花种类等对板材性能的影响.结果表明,当木灰比为0.25,采用沙柳刨花,高钙粉煤灰替代量可达到40%,制备得到的板材性能指标能够达到水泥木屑板标准的要求;用杨木刨花代替沙柳刨花,板材强度明显增加,粉煤灰的替代量达到50%,仍能制备合格产品;激活剂氯化钙、三乙醇胺和硫酸钠作用比较显著,可明显提高板坯早期强度,抑制反弹.     

半干法粉煤灰水泥刨花板的生产工艺

通过改进粉煤灰水泥刨花板的生产工艺,在不改变水泥的等级、保证板材力学性能的前提下,选择粉煤灰的替代比例、添加剂的种类、用量以及密度、水灰比和灰木比等因子进行试验,以确定粉煤灰水泥刨花板的最佳工艺.     

用粉煤灰改善石灰石粉混凝土的氯离子扩散性

采用RCM法测定混凝土试件的氯离子扩散系数,研究了石灰石粉单掺以及粉煤灰和石灰石粉双掺对混凝土抗氯离子渗透性能的影响.结果表明,混凝土中掺入石灰石粉对其抗氯离子渗透不利;粉煤灰能有效降低石灰石粉混凝土的氯离子扩散系数,提高其抗氯离子渗透能力;当混凝土中石灰石粉掺量为20%时,粉煤灰改善混凝土抗氯离子渗透性能的最佳掺量为20%.     

谈粉煤灰对混凝土性能的改善

本文通过对粉煤灰的性质的分析,将其在掺入混凝土中,可以改善混凝土的性能,特别是粉煤灰对混凝土抗硫酸盐侵蚀性能改善进行了分析,为利用粉煤灰创造了条件。     

路面基层中粉煤灰SO3含量超标的危害及防治对策

石灰粉煤灰稳定碎石基层松散从而导致沥青路面结构开裂、起拱,经分析是由于基层中粉煤灰原材料SO3含量偏高,遇水后产生化学反应造成结构体积膨胀,最终导致基层和面层整体破坏。本文进一步分析粉煤灰原材料SO3含量偏高的原因,进而提出石灰粉煤灰稳定碎石结构原材料及施工过程的质量控制措施。     

粉煤灰刨花板的胶合机理

粉煤灰刨花板是以粉煤灰为主要原料 ,木刨花为增强材料 ,经热压而成的一种复合板材。本文从粉煤灰的物理化学性质、活性、水化机理以及温度和外加剂作用机理等方面着手 ,通过扫描电镜 (SEM)、X-衍射仪 (XRD)等微观分析结果 ,对粉煤灰刨花板的胶合机理进行了探讨。结论认为 ,其胶合机理是一个包含多种作用的复杂的物理化学过程     

粉煤灰掺量对粉煤灰水泥竹碎料板生产中原料相适性的影响

水泥竹碎料板是利用水泥、粉煤灰和竹碎料为主要原料,辅之以其他添加剂,经一定加工工艺制成的一种无机刨花板.煤灰水泥竹碎料板是在水泥竹碎料板生产中以一定量的粉煤灰替代一定量的水泥制成的一种无机刨花板,它质量轻,强度高,耐久性、耐候性、耐火性、耐热性、隔音性好,可装饰性能强(板材具有很好的机械加工性能,可对其进行钻、锯、磨、钉、胶结等加工,板材表面可贴装饰纸、喷灰浆和油漆等),并具有较好的环保功能(以无机物水泥、粉煤灰作为胶凝剂,不存在游离甲醛和酚等污染,符合人们的健康要求),是一种优质的建筑装修材料,可广泛应用于室内外建筑装修等领域.     

粉煤灰高效活化剂

一种新型高分子复合材料——“ＨＢ粉煤灰高效活化剂”由安徽大学高分子材料研究所研制成功，为高掺量、高水平利用粉煤灰开辟了一条新途径。原本严重污染环境的粉煤灰成为代替水泥的廉价材料，兼有经济和环保的双重效应。粉煤灰是以煤为燃料的火力发电厂烟道中排出的粉状...     

粘土路基施工技术

本文主要论述了路基填筑粘土不利因素以及粘土掺灰的机理特点，同时介绍了粘土处理在工程施工中的技术应用。     

Multielement analysis using PIXE for beneficial use of ashes from a biomass power plant

Elemental analysis of wood fuels and ashes from a biomass power plant was carried out using particle induced X-ray emission (PIXE) to confirm that the ashes can be utilized safely. The power plant produced four types of ash: one cinder and three fly ashes. Ignition loss tests revealed that the cinder included little unburned carbon, while the unburned carbon concentrations in the fly ashes were considerably higher. From PIXE analysis, more than 20 elements were found in all the ashes and it was shown that aluminum, silicon, calcium, potassium, and iron were the major elements in the ashes. In the fly ash collected in a bag filter, sodium, sulfur, and chlorine were also classified as major elements. Although chromium, arsenic, and lead were detected in all the ashes, leaching tests indicated that there were no potential problems associated with landfill treatment of the ashes. It was assumed that temporal fluctuation in the concentrations of major elements in the ashes was not significant. Nine kinds of waste wood fuels were analyzed by PIXE and 24 elements were determined. Lead was detected in all the woody fuels, but arsenic was not detected. Part of this report was presented at the 57th Annual Meeting of the Japan Wood Research Society, Hiroshima, August 2007.     

Characterization of the ashes of Nigerian red and white mangrove woods

Summary An investigation of the analytical characterization of ashes of Nigerian red and white mangrove woods was carried out. The ashes obtained from the woods were subjected to intense heating in water to extract the chemical constituents. Some quantitiy of rock salt was also dissolved in water and analysed. The solution obtained from the ashes were differently analysed for K⁺, Na⁺, Ca²⁺, Mg²⁺, Cl^–, SO₄, PO₄, NO₃ and total solid. The pH of each sample solution was measured. Various concentrations of these cations and anions were obtained and they were found in each case to be more than those obtained from rock salt. Solutions obtained from the ashes of red and white mangrove woods have wide applications particularly in Nigeria as tasty food additive and in softening and accelerating the cooking time of yam, plantain and beans in particular.     

Composition of inorganic elements and the leaching behavior of biomass combustion ashes discharged from wood pellet boilers in Japan

To evaluate the characteristics of wood ash as fertilizer, composition of inorganic elements and the leaching behavior were studied. The leaching behavior was evaluated by three leaching methods using different solvents (water, hydrochloric acid, and acetic acid: Japanese leaching test Nos. 18 and 19 and modified toxicity characteristic leaching procedure prescribed by the US Environmental Protection Agency). The ash composition varied according to raw materials for fuel and ash collection systems. Concentration of Na, Al, Si, and V became higher in bark ashes while that of K became higher in wood ashes. Pb, Cd, Se, and Zn were more volatile and enriched in fly ashes. Of the nutrient elements, K showed high water solubility and its phytoavailability also appeared high, although the amount of water-soluble K was low in bark ash. Ca and Mg had intermediate solubility while P was less soluble in both water and acetic acid. The amount of hazardous substances having leached was low for most, but not all the ashes, in terms of Pb, Cr and As. Nevertheless, the phytoavailability of these hazardous substances after their application to the forest appeared low, due to their amphoteric leaching behavior and the acidity of Japanese forest soils.     

茶叶灰分和水分与品质关系

阐述了茶叶灰分及其检验意义和世界茶叶标准中的灰分指标,分析了我国茶叶灰分检验现状和影响茶叶灰分的主要因素,提出了有效控制茶叶灰分的4项措施;同时从营养化学的角度分析了水分对茶叶中微生物的生长繁殖、茶化反应、营养成分及风味物等方面的直接影响,低水分活度对茶叶品质起到的稳定作用。     

Determination of cations and anions in the ashes of some medicinally used tropical woods

Summary The ashes of some medicinally used tropical woods were characterised. These were Afzelia africana, Alstonia congensis, Antiaris africana, Terminalia ivorensis, Azadirachta indica, Ricinodendron heudelotti, Chlorophora excelsa and Daniellia ogea. The ashes were obtained by treating wood in a muffle furnace, after which the ashes dissolved in distilled water. The very alkaline solutions obtained were analysed for Na⁺, K⁺, Ca²⁺, Mg²⁺, Mn²⁺, Fe²⁺, Cu²⁺, Cl^-, SO ₄ ^2- and PO ₄ ^3- . Due to wide medicinal application of these wood species experiments were made to determine the cations and anions which may be active ingredients in the compounds (drugs) used in the treatment of differet ailments.The authors are thankful to A. Amusan of Soil Science Department, Obafemi Awolowo University, Ile-lfe for technical assistance     

浅谈二灰碎石基层施工

本文主要论述了二灰碎石基层的施工方法及养护措施。     

多孔板体结构足尺性能分析

本文通过验证足尺试验数据。深入分析了诸如蛋白石这样的疏松多孔矿料同灰土构成的混合料在路面结构中表现出的独特有效的抗冻作用机理。     

Do higher summer temperatures restrict the dissemination of Hymenoscyphus fraxineus in France?

Hymenoscyphus fraxineus is an invasive pathogen that severely affects European ashes, jeopardizing the use of this species in forestry. However, even aggressive invasive pathogens require environmental conditions conducive to disease development. Hence, H. fraxineus survival at temperatures above 35°C is limited, which could reduce its impact in southern Europe. This study examined the effect of environmental conditions, mainly summer temperatures, on ash dieback development in southeast France between 2015 and 2016. Fourteen sites were selected according to altitudinal and longitudinal gradients covering a wide range of mean summer temperatures. Disease severity, density of infected and healthy rachises in the litter and quantity of apothecia produced on infected rachises were measured. Results point to limited disease severity in this area because of the occurrence of high summer temperatures that are unfavourable to the pathogen. In a context of global warming, increases in temperatures could have a positive impact on ashes by limiting ash dieback development.