绿色环保水泥基陶粒吸音材料的研究

发布时间：2018-08-16 14:32

【摘要】：随着轨道交通的高速发展,交通噪音污染问题越来越凸显,人们对吸音降噪材料的研究也不断深入。陶粒这种绿色环保材料,因为具备良好的吸音功能而备受人们的关注。利用陶粒制成的多孔吸音材料具有质量轻,吸声性能、耐久性、防火性好等优点,符合交通运输线特别是城市地铁线使用要求,因此越来越受到研发人员的青睐。本文以陶粒、水泥为主要原材料,添加聚丙烯纤维和外加剂等,通过混合、搅拌、压制、养护等工艺制作绿色环保的吸音材料。整个研究过程包括选择原材料,拟定配合比,研究分析成品材料的吸声性能、力学性能、耐久性能和防火性能,进一步调整、优化配合比,保证吸音材料多孔轻质,体积密度在1200~1400kg/m3之间;保证材料达到高性能吸音材料要求,且降噪系数(NRC)达到国家Ⅱ级标准,即0.6≤NRC≤0.8;保证材料满足地铁轨道板承载要求:28d抗压强度≥8.0MPa,28d抗折强度≥2.0MPa;保证材料耐久性、防火性达到国家相关标准。为实现上述目标,主要开展了以下内容的研究工作:(1)优选原材料:通过试验比较陶粒物理力学性能,选择堆积密度低,吸水率低、筒压强度高的陶粒作为吸音材料的原材料。(2)吸音材料初始配合比设计:通过控制吸声材料的密度指标并考虑强度因素,调整陶粒、水泥、水、纤维、减水剂用量,形成初始配合比,即陶粒用量为65%~60%,水泥用量为35%~40%,水灰比为0.19,减水剂掺量为1.2%,纤维掺量为0.3%,按初始配合比制成了密度在1220~1430 kg/m3范围内,7d抗压强度在7.4~11.3MPa内的陶粒吸音材料。(3)研究吸音材料力学性能,以初始配合比为基础,通过试验分析陶粒与水泥比例、粗细陶粒比例、水泥标号、纤维掺量对力学性能的影响,进一步控制强度和密度指标,调整陶粒粒径和级配,优化配合比,得到陶粒用量为60%(其中粗细陶粒的比例为30:70~50:50之间),其他材料用量和参数不变,可以制成的材料密度在1300kg/m3左右,7d抗压强度值在9MPa左右的陶粒吸音材料,达到吸音材料的技术要求。(4)研究吸音材料吸声性能,采用驻波管法对材料吸声系数进行测试,分析陶粒粒径、材料密度、材料厚度、纤维含量对吸声系数的影响。通过试验发现,粒径增大,材料吸声系数峰值点向低频段方向移动;密度增大,吸声系数有所降低,但是低频段吸声系数略有提高;厚度增大,材料吸声系数有所提高,特别是低频段吸声系数提高较为明显;当粗陶粒粒径为6~8mm、细陶粒粒径为2~4mm、材料密度在1200~1300 kg/m3之间、厚度为100mm、纤维添加量在0.3%附近时能最大程度的提高材料吸声系数。所研制的吸音材料经测试属于高性能吸音材料,降噪系数(NRC)达到了国家吸声性能等级Ⅱ级标准:(NRC)≥0.6。采用圆管理论分析各因素对材料吸声性能的影响,与试验分析对比结果是吻合的。(5)测试吸音材料使用性能,包括抗冻融性能和防火性能,保证技术指标达到国家标准。本吸音材料设计抗冻等级F200,在经历200次冻融循环后,材料的质量损失率为3.7%,相对动弹性模量为82.4%,满足国际对材料抗冻融性能的要求,在自然环境下能够正常使用;同时,通过燃烧测试,吸音材料质量损失率△m=9.4%,小于规范规定值50%;炉内平均温升△T=6℃,小于规范规定值30℃;试样持续燃烧时间为t=0,满足规定值要求;总燃烧值PCS=0.47,低于规定值2.0;因此吸音材料的燃烧性能达到国家A1级,满足地铁吸音材料对防火性能的要求。
[Abstract]:With the rapid development of rail transit, the problem of traffic noise pollution is becoming more and more prominent, and the research on sound-absorbing and noise-reducing materials is deepening. Ceramsite, a green environmental protection material, attracts people's attention because of its sound-absorbing function. In this paper, ceramsite, cement as the main raw material, polypropylene fiber and additives are added, through mixing, stirring, pressing, curing and other processes to produce green sound-absorbing materials. Select raw materials, formulate mix proportion, study and analyze the sound absorption performance, mechanical properties, durability and fire resistance of the finished materials, further adjust and optimize the mix proportion, ensure that the sound absorption material porous light weight, volume density between 1200-1400kg/m3; ensure that the material meets the requirements of high-performance sound absorption materials, and noise reduction coefficient (NRC) meets the national level II standards. In order to achieve the above objectives, the following research work has been carried out: (1) Optimizing raw materials: Compressive strength of 28 days (> 8.0 MPa), flexural strength of 28 days (> 2.0 MPa), durability of materials, fire resistance to meet the relevant national standards. (2) Initial mix proportion design of sound-absorbing materials: through controlling density index of sound-absorbing materials and considering strength factors, adjusting the dosage of ceramsite, cement, water, fiber, water reducer, the initial mix ratio is formed, that is, the dosage of ceramsite is 65% ~ 60%, the dosage of cement is 3%. 5%~40%, water cement ratio is 0.19, water reducer is 1.2%, fiber is 0.3%. According to the initial mix proportion, ceramsite sound absorbing materials with density in the range of 1220~1430 kg/m3 and compressive strength in the range of 7.4~11.3 MPa for 7 days are prepared. (3) The mechanical properties of sound absorbing materials are studied. Based on the initial mix ratio, the ratio of ceramsite to cement and the ratio of coarse to fine ceramsite are analyzed through experiments. By further controlling the strength and density index, adjusting the grain size and gradation of ceramsite and optimizing the mixing ratio, the amount of ceramsite is 60% (the proportion of coarse and fine ceramsite is 30:70-50:50), and other materials and parameters are unchanged. The density of the material can be made is about 1300 kg/m3, and the compressive strength is about 7 days. (4) The sound absorption properties of the materials were studied, and the sound absorption coefficient was measured by standing wave tube method. The influence of the particle size, material density, material thickness and fiber content on the sound absorption coefficient was analyzed. When the density increases, the sound absorption coefficient decreases, but the sound absorption coefficient increases slightly in the low frequency band; when the thickness increases, the sound absorption coefficient increases, especially in the low frequency band; when the coarse ceramsite particle size is 6-8 mm, the fine ceramsite particle size is 2-4 mm, the material density is between 1200-1300 kg/m3, and the thickness is between 1200-1300 kg/m3. The sound absorption coefficient of the material can be improved to the greatest extent when the fiber content is about 0.3%. The sound absorption material developed in this paper belongs to the high performance sound absorption material. The noise reduction coefficient (NRC) reaches the national sound absorption grade II standard: (NRC) > 0.6. (5) Testing the performance of sound-absorbing materials, including freeze-thaw resistance and fire resistance, to ensure that the technical indicators meet the national standards. This sound-absorbing material design freeze-thaw resistance grade F200, after 200 freeze-thaw cycles, the material mass loss rate is 3.7%, the relative dynamic modulus of elasticity is 82.4%, to meet the international anti-freeze-thaw performance of materials. Requirements, in the natural environment can be used normally; at the same time, through combustion testing, sound absorption material mass loss rate (?) M = 9.4%, less than 50% of the specified value; furnace average temperature rise (?) T = 6 (?) C), less than the specified value of 30 (?); sample continuous combustion time (?) t = 0, to meet the specified value requirements; total combustion value PCS = 0.47, less than the specified value of 2.0; therefore, sound absorption material The combustion performance of the material reaches the national A1 level, and meets the requirements of the subway sound absorbing material for fire resistance.
【学位授予单位】：广西科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU552

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