秸秆纤维自保温混凝土砌块砌体性能试验研究

发布时间：2018-04-05 07:57

本文选题：泡沫混凝土　切入点：粉煤灰　出处：《延边大学》2017年硕士论文

【摘要】：目前,我国严寒地区大部分建筑人采用外墙外保温的形式,此形式存在着诸多缺点,其中最大的缺点在于外墙保温材料的使用年限为25年,远远低于建筑本身的50-100年的使用寿命,导致外墙保温系统一般需要二次维修;其次外墙外保温材料由于自身原因,使得外墙外保温系统具有较大的防火安全隐患。因此必将出现一种新的保温形式来取代外墙外保温,因此应运而生了外墙自保温系统,它也将成为外墙保温的必然趋势。此外针对我国现行的建筑节能标准,将粉煤灰和秸秆纤维作为主要掺合料,解决了粉煤灰大量堆积造成的土地浪费,以及废弃农作物秸秆处理对环境的破坏等问题,为资源的回收再利用提供方向。最后针对考虑到我国资源现状,本文提出利用粉煤灰、秸秆纤维为主要材料,加入高效发泡剂,通过机械方法搅拌,自然养护研制出一种符合节能要求的自保温材料—秸秆纤维增强粉煤灰自保温泡沫混凝土。本研究的具体工作方法和研究结果如下:(1)确定秸秆纤维粉煤灰自保温泡沫混凝土的配合比。以秸秆纤维和粉煤灰作为主要变量,其中粉煤灰掺量分别为35%、40%、45%,秸秆纤维掺量为0%、1%、2%。通过对混凝土抗压强度、干体积密度和干燥收缩进行对比,得出最佳配合比为秸秆纤维掺量为1%,粉煤灰掺量为40%,此时自保温泡沫混凝土的强度可达到5.0MPa以上,密度等级为916kg/m3,为A05、B09级泡沫混凝土。(2)研究秸秆纤维粉煤灰自保温泡沫混凝土砌块各项性能。在最佳配合比下对尺寸为600×240×200的泡沫混凝土砌块的干密度、抗压强度、抗折强度、导热系数、抗冻性和质量吸水率等各项性能按照规范进行试验研究,得出泡沫混凝土砌块各项性能均满足《泡沫混凝土砌块》JC/T1062-2007规范要求。可见泡沫混凝土试块的力学性能和热工性能良好。(3)对秸秆纤维粉煤灰自保温泡沫混凝土砌块进行ANSYS有限元热分析和力学分析。热分析中对砌块的温度场分布和热流密度分布进行分析,发现砌块内部温度分布均匀,不易产生温度裂缝。(4)研究秸秆纤维粉煤灰自保温泡沫混凝土砌块砌体的基本力学性能。利用砌块的主尺寸及半块的辅助尺寸块体制成三层的砌块砌体,对其轴心抗压强度以及沿通缝的抗剪强度进行试验,得出其破坏形态以及本构关系。得出轴心抗压强度和沿通缝的抗剪强度均符合要求,为秸秆纤维粉煤灰自保温泡沫混凝土砌块的推广提供依据。通过对秸秆纤维粉煤灰自保温泡沫混凝土砌块进行试验研究得出秸秆纤维自保温泡沫混凝土具有很好的力学性能,强度可以达到5.0MPa以上,保温隔热性能良好,导热系数为0.19W/(m·K),抗冻性能良好,15次冻融循环后的质量和强度均符合严寒地区的抗冻性要求。可以在严寒地区推广使用,是集承重保温为一体的秸秆纤维自保温泡沫混凝土砌块。但在砌块的砌筑过程中应该采用保温砂浆,从而确保整个墙体的保温性;此外对砌块的其他性能需要更深层次的研究,例如抗渗性等,以便于秸秆纤维粉煤灰自保温泡沫混凝土砌块的推广使用。
[Abstract]:At present, most of the cold regions of China by building exterior wall insulation form, this form has many disadvantages, the biggest disadvantage is that the external wall thermal insulation material life for 25 years, the building itself is far less than the 50-100 years of life, resulting in external wall insulation systems generally require two maintenance; second exterior insulation materials because of their own reasons, a fire safety hazard because of the large exterior insulation system. It will be a new form to replace the insulation of exterior wall insulation, thereforebecome external wall insulation system, it will become the inevitable trend of external wall insulation. In addition to the existing standard of building energy saving in our country, the fly ash and straw fiber as main admixture, solved a large number of fly ash caused by the accumulation of land waste and waste destruction of the environment problems of straw treatment, for the capital The source of the recycling direction. Finally, considering the current situation of China's resources, this paper proposes the use of fly ash, straw fiber as the main material, adding high foaming agent by mechanical mixing method, natural curing developed a meet the energy requirements of the insulation material of straw fiber reinforced fly ash self insulation foam concrete. Study of specific methods and results are as follows: (1) determined with straw fiber fly ash self insulation foam concrete. Straw fiber and fly ash as the main variable, the fly ash content is 35% and 40% respectively, 45%, straw fiber content is 0%, 1%, 2%. on the compressive strength of concrete dry bulk density, and dry shrinkage are compared, the optimum mix ratio of straw fiber content is 1%, the amount of fly ash is 40%, the self insulation foam concrete strength can reach more than 5.0MPa, density grade 916kg/m3, A05, B09 (2). The foam concrete self insulation foam concrete of straw fiber fly ash block. The performance in the best mix proportion to the size of the dry density of foam concrete block, 600 x 240 x 200 of the compressive strength, flexural strength, thermal conductivity resistance, frost resistance and water quality the performance experiments were carried out according to the standard, the performance of foam concrete block can meet the requirements of >JC/T1062-2007 < foam concrete block. Visible foam concrete block the mechanical properties and good thermal properties. (3) of straw fiber fly ash self insulation foam concrete block was analyzed by ANSYS finite element thermal analysis and mechanical thermal analysis. To block the temperature distribution and heat flux distribution is analyzed, it is found that the internal temperature distribution of the block is uniform, not easy to produce temperature crack. (4) fly ash of straw fiber insulation foam The basic mechanical properties of foam concrete block masonry. The main block size and half block size block masonry auxiliary body made of three layers, the axial compressive strength and shear strength along the seam test, the failure pattern and the constitutive relation. The axial compressive strength and straight seam the shear strength meets the requirements, provide the promotion of self thermal insulation foam concrete block for straw fiber fly ash. It is concluded that straw fiber insulation foam concrete has good mechanical properties of straw fiber fly ash self insulation foam concrete block, the strength can reach above 5.0MPa, good insulation properties, thermal conductivity 0.19W/ (M - K), good frost resistance, after 15 freeze-thaw cycles. The quality and strength meet the requirements. The frost resistance of cold regions can be promoted in the cold area, is set As one of the straw fiber bearing insulation insulation foam concrete block masonry. But in the process of building blocks should be used for insulation mortar, so as to ensure the insulation of the wall; in addition to other properties of the block need further research, such as anti permeability, in order to promote the use of straw fiber fly ash self insulation foam concrete block.

【学位授予单位】：延边大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU522.3;TU364

【参考文献】