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本文通过介绍泡沫混凝土的组成及其原材料的选择,论述泡沫混凝土的性能特点,指出国内泡沫混凝土生产应用中存在的一些问题,同时讨论泡沫混凝土的生产施工工艺及应用前景。 相似文献
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对于非均质性严重的油藏来讲,水驱之后的剩余油多分布在低渗透层和孔隙的角隅中,在此情况下,为提高低渗透层的储量动用程度,确保高效开发和稳产,开展了氮气泡沫调驱试验,要求注入的氮气加泡沫剂在高水洗层内形成大量的泡沫,进而封堵注水串流通道,改善油藏的非均质性,提高注水驱油的波及体积,根据地层流体性质和油藏实际条件开展了氮气泡沫调驱配方体系中泡沫剂性能的评价,并筛选出较适宜的泡沫剂和用量。 相似文献
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随着建筑节能理念的推广,泡沫混凝土作为一种轻质的保温建筑材料,被越来越多地应用到各种场合。对于泡沫混凝土的研究也越来越受到重视,本文就对泡沫混凝土的生产工艺以及国内外的应用现状进行了分析。 相似文献
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拉胀材料因其特殊性能在材料领域备受重视.将负泊松比效应应用在泡沫混凝土中,可使其具备良好的力学性能与吸能效果.本试验利用化学发泡法制备了三种不同孔隙形态的泡沫混凝土,分别为闭孔泡沫混凝土、连通孔泡沫混凝土、内凹孔泡沫混凝土.利用图像法对泡沫混凝土的干密度和孔隙结构参数进行表征,通过万能试验机测试了泡沫混凝土的静态压缩强度、抗折强度,通过工业相机及数字散斑相关方法(DSCM)研究了泡沫混凝土的区域形变行为以及泊松比值.结果表明:泡沫混凝土的孔隙率、孔径及干密度与发泡剂的添加量有关,添加量越多,干密度越小,孔隙率和孔径增大;泡沫混凝土的抗压、抗折强度也与发泡剂的添加量有关,其强度随着添加量的增多而减小,但孔隙呈内凹状的泡沫混凝土具有较高的抗压强度和抗折强度,内凹孔泡沫混凝土的压缩断裂能为33.9×103 J/m3,相比闭孔泡沫混凝土提高44.9%.DSCM表明内凹孔泡沫混凝土在压缩过程中会出现明显的收缩效应,其收缩率为闭孔泡沫混凝土的37.5%,压缩期间负泊松比值最大可达-3.7. 相似文献
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在阐述泡沫混凝土的定义及分类的基础上,总结泡沫混凝土在屋面防水工程应用中的特点,并分析常见泡沫混凝土屋面渗漏的各种原因,最后提出泡沫混凝土隔热层屋面渗漏的处理方法. 相似文献
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轻质泡沫混凝土有自重小、极好的隔音和隔热性能,是一种有前途的结构材料。为了研究轻质泡沫混凝土的物理性能,该文对不加粉煤灰和掺加粉煤灰泡沫混凝土的力学性能进行一系列试验研究,还研究25次冻融循环对混凝土抗压强度的影响。试验结果如下:1)硬化泡沫混凝土的密度与混合料中的泡沫含量密切相关。2)随着泡沫混凝土密度增大,其抗弯强度降低。3)在相同密度下,含粉煤灰混合料的抗压强度比不含粉煤灰的试样低20%左右。研究结果可为轻质泡沫混凝土开发提供参考。 相似文献
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原状脱硫石膏泡沫混凝土的制备与性能研究 总被引:1,自引:1,他引:0
原状脱硫石膏泡沫混凝土是在自主研发的原状脱硫石膏高强胶凝材料体系的基础上,以H2O2为化学发泡剂,同时在催化剂MnO2的作用下,利用反应后产生的O2达到自主发泡的目的,并掺入一定量的聚丙烯纤维和稳泡剂硬脂酸钙分别起到增强增韧和稳定气泡的作用。实验研究了不同组分对原状脱硫石膏泡沫混凝土各项性能的影响,包括干密度、抗压强度、导热系数、气孔率、线性收缩率、吸水率等性能,并利用扫描电子显微镜观察了不同发泡剂掺量时孔结构的微观形貌,最终确定了最佳配合比:胶凝材料体系组分为1(所包含组分质量比为:m(原状脱硫石膏)∶m(矿渣)∶m(水泥)∶m(石灰粉)∶m(水玻璃)∶m(减水剂)=60∶31∶9∶6∶0.7∶1.8),发泡剂掺量为2.5%、硬脂酸钙为3.2%、纤维为0.15%、水胶比为0.38,均外掺(质量比)。原状脱硫石膏泡沫混凝土各项性能均满足标准JC/T 266-2011《泡沫混凝土》的相关要求。本研究大大扩大了工业废石膏的应用范围,有效节约了自然资源,具有重要的社会现实意义。 相似文献
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通过对7片秸秆板轻钢高强泡沫混凝土剪力墙(SSRC剪力墙)足尺试件的轴心受压试验,考察了其在轴心荷载作用下的受力性能、破坏模态和承载力,分析覆盖秸秆板、是否填充泡沫混凝土、泡沫混凝土强度和墙体厚度等因素对剪力墙试件轴心受压性能的影响。试验结果表明:剪力墙的破坏模态主要表现为轻钢立柱的局部屈曲和泡沫混凝土的局部压碎;与未填充泡沫混凝土墙体相比,填充A05级泡沫混凝土的竖向承载力和竖向刚度分别提高1.6倍和2.2倍,填充A07级泡沫混凝土可以提高2.2倍和3.1倍;是否覆盖秸秆板对墙体竖向承载力的影响很小;轻钢立柱截面宽度由89 mm增加到140 mm,墙体厚度由205 mm增加到256 mm,墙体竖向承载力提高了60%~70%。针对覆盖新型材料秸秆板的剪力墙受力性能和破坏模式,总结中、美两国规范及已有研究文献中的轴心受压构件承载力计算公式,提出SSRC剪力墙轴心受压承载力简化计算公式,其计算值与试验值基本一致。 相似文献
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This paper studies the four-point bending response and failure mechanisms of sandwich panels with corrugated steel faces and either plain or fibre-reinforced foamed concrete core. Mechanical properties of both plain and polyvinyl alcohol fibre-reinforced foamed concrete were obtained, which are needed for the design of sandwich panel and numerical modelling. It is found that the fibre-reinforcement largely enhances the mechanical behaviour of foamed concrete and composite sandwich panels. Finite element code Abaqus/Standard was employed to investigate the influence of face/core bonding and fastening on the four-point bending response of the sandwich panels. It was found that face/core bonding plays a crucial role in the structural performance while the influence of fastening is negligible. 相似文献
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为了研究建立飞机机轮与特性材料拦阻系统(Engineered Material Arresting System,简称EMAS)之间作用力的计算模型,设计建造了专门的实验装置。通过改变机轮尺寸、运动速度、负重、轮胎胎压,泡沫材料的厚度与强度等参数,开展了大量实验,发现了泡沫材料在机轮碾压下的一些物理现象,获得了实验数据。在这些实验结果的基础上建立了拦阻力模型,并对模型的准确度进行了验证。研究表明:1) 机轮运动速度对拦阻力的影响较小;2) 被机轮碾压后材料是处于压透状态还是处于未压透状态对拦阻力有重要影响;3) 泡沫材料的强度水平对拦阻力的影响是复杂的,增加材料强度可能降低拦阻力;4) 建立的拦阻力模型较好地反映了实验现象;5) 在实验范围内,模型对机轮所受拦阻力计算结果相对偏差的平均值小于10%,最大相对偏差为17%。 相似文献
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Foam concretes are divided into two groups: on the one hand the physically foamed concrete is mixed in fast rotating pug mill mixers by using foaming agents. This concrete cures under atmospheric conditions. On the other hand the autoclaved aerated concrete is chemically foamed by adding aluminium powder. Afterwards it is cured in a saturated steam atmosphere.New alternatives for the application of foam concretes arise from the combination of chemical foaming and air curing in manufacturing processes. These foam concretes are new and innovative building materials with interesting properties: low mass density and high strength. Responsible for these properties are the macro-, meso- and microporosity. Macropores are created by adding aluminium powder in different volumes and with different particle size distributions. However, the microstructure of the cement matrix is affected by meso- and micropores. In addition, the matrix of the hardened cement paste can be optimized by the specific use of chemical additives for concrete.The influence of aluminium powder and chemical additives on the properties of the microstructure of the hardened cement matrices were investigated by using petrographic microscopy as well as scanning electron microscopy. 相似文献
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B. Figiela K. Korniejenko M. Hebdowska-Krupa 《Materialwissenschaft und Werkstofftechnik》2023,54(4):466-473
Current research focuses heavily on geopolymer concrete as possible applications for insulation materials. The aim of the research is to test the strength properties of lightweight geopolymer concrete after exposure to high temperatures. Waste material from the Wieczorek mine (Poland) was used to produce the foamed geopolymers. Alkaline activation took place by mixing the mine powder with an aqueous solution of sodium hydroxide combined with an aqueous sodium silicate with a concentration of 10 M. Prepared geopolymer samples after temperature curing at 75 °C for 24 hours in a laboratory dryer, they were seasoned for 28 days, after which the strength properties were determined. Mechanical tests: compressive strength and bending strength were carried out at temperatures: 20 °C, 200 °C, 600 °C, 800 °C, 1100 °C. Research has shown the precursor activation with the presence of hydrogen peroxide enabled the manufacturing of foamed geopolymers. Heating in the temperature range up to 1100 °C influenced, to some extent, the total porosity of the tested foams. The geopolymer foams based on coal gangue present stable mechanical properties in the range up to 800 °C. No sharp mechanical performances decrease or material chipping was observed. Only colour change of heated samples occurred. 相似文献
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Chemical and mechanical foaming techniques are commonly used in foam concrete technology for developing lightweight construction materials. The characteristics of the foam before the lightweight structure sets and maintains its shape has a great impact on the properties of foamed concretes. The tendency of the foams to coalesce and collapse during the preparation process brings some challenges in controlling the properties of cellular structures. Consequently, it is critical to improve the stability of fresh foams in order to produce high quality cellular structures using a predictable and reliable approach. Aggregating the liquid film around bubbles is known to be effective in improving the stability of foams, but the impact of this stabilizing method has not been investigated for foam concrete applications. In this paper, Xanthan gum (with a thickening capacity) has been utilized as the foam stabilizer to aggregate the liquid film. This stabilizing method is shown to significantly enhance the pore size distribution of foam concretes. The resulting pre-made foams are remarkably more stable than the control foam, and the mechanical properties of the final cellular structure are considerably improved (about 34% in mechanical foaming and 20% in the chemical foaming technique). 相似文献