硅酸钙板的制备及纤维增强

发布时间：2018-10-16 20:16

【摘要】：硅酸钙板的主要成分是硅酸盐水合物,具有强度高、导热系数低、使用温度高、隔音隔热效果好、使用安全等优点。硅酸钙板应用十分广泛,室内主要用于隔墙、吊顶、天花板、写字楼的防火墙和地面铺设等；室外主要用作外墙挂板和外墙贴面。但在实际应用中硅酸钙板常常表现为破损率高、表面平整度差、易产生裂缝和起皮、吸水率过高,吸水后板材强度急剧下降,导热系数急剧升高,最终导致硅酸钙板的耐久性下降。因此对于提高硅酸钙板的性能极为迫切。本文采用二氧化硅、熟石灰和水泥为原材料,经过常压凝胶预备反应和蒸压养护后生成硅酸钙水合物。研究了原材料中Ca/Si比和水热反应的温度时间等因素对合成产物的组成以及对硅酸钙板的弯曲强度的影响；同时比较了玻璃纤维和岩棉纤维在硅酸钙体系中的耐腐蚀性能和耐腐蚀机理；最后研究了纸纤维和岩棉纤维在硅酸钙板体系中的纤维增强效果,得到以下结论：(1)实验研究了不同Ca/Si、水热反应温度和时间下对生成物组成的影响,通过XRD、 IR和TG-DSC对生成物进行测试分析得到：当Ca/Si为0.83、水热反应温度和时间分别为180-C和8h时,生成托贝莫来石型硅酸钙水合物,并且养护温度越高以及时间越长,生成的托贝莫来石型硅酸钙水合物越多,弯曲强度也越高,最高可达到16MPa。(2)在温度为80℃的饱和石灰水溶液中加速老化12天后,玻璃纤维的表面基本被腐蚀,呈鳞状,其质量损失达到22%,而岩棉纤维表面几乎没有被腐蚀的痕迹,质量基本保持不变。在温度为180℃的饱和石灰水溶液中,在水热条件下腐蚀20h,玻璃纤维表面形成一层可以脱去的壳层,而其他几种岩棉表面被腐蚀的形貌各有不同,主要表现为生成了某种物质附着在纤维表面。得到岩棉纤维在碱性溶液中的腐蚀机理是溶液中的氢氧根离子与纤维中的阳离子反应生成了其他的物质,导致纤维内部的网状结构遭到了破坏。(3)当硅酸钙板中纸纤维含量在0-8%范围内,随着纸纤维含量的增加,板材的强度逐渐降低,而板材的韧性越好；当加入0-8%的岩棉纤维时,随着岩棉纤维的含量的增加,板材强度先是增加后下降,板材始终呈脆性断裂。然而当纸纤维和岩棉纤维含量均为4%时,板材强度最高,可达到16MPa,其抗冻融性能也较好。
[Abstract]:The main component of calcium silicate plate is silicate hydrate, which has the advantages of high strength, low thermal conductivity, high temperature, sound insulation and safety. Calcium silicate board is widely used in indoor, mainly used for partition wall, ceiling, office building firewall and floor laying, etc. Outdoor is mainly used as external wall hanging board and external wall veneer. However, in practical application, calcium silicate plates are often characterized by high breakage rate, poor surface smoothness, easy to produce cracks and peeling, high water absorption rate, sharp decrease of plate strength after water absorption, and sharp increase of thermal conductivity. Finally, the durability of calcium silicate plate is decreased. Therefore, it is urgent to improve the performance of calcium silicate plate. In this paper, silica, hydrated lime and cement were used as raw materials to form calcium silicate hydrate after preparation reaction and autoclaved curing under atmospheric pressure gel. The effects of the ratio of Ca/Si in raw materials and the temperature and time of hydrothermal reaction on the composition of the synthesized products and the bending strength of calcium silicate plates were studied. At the same time, the corrosion resistance and mechanism of glass fiber and rock cotton fiber in calcium silicate system were compared. Finally, the fiber reinforcement effect of paper fiber and rock cotton fiber in calcium silicate plate system was studied. The main conclusions are as follows: (1) the effects of different hydrothermal reaction temperature and time of Ca/Si, on the composition of the product are studied experimentally. The results of XRD, IR and TG-DSC analysis show that when the Ca/Si is 0.83, the hydrothermal reaction temperature and time are 180-C and 8h, respectively. The higher the curing temperature and the longer the curing time, the more Tobiamurite calcium silicate hydrates are formed and the higher the bending strength is, Up to 16 MPA 路(2) after 12 days of accelerated aging in saturated lime solution at 80 鈩，

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