摘要
试验探讨了SiO_2气凝胶粒径对隧道防火砂浆强度、耐水性与导热性能的影响规律。按照体积法设计防火砂浆配合比,将骨料体积固定为60%,采用0.5~2、0.5~4 mm两种粒径的商用SiO_2气凝胶取代骨料,取代率分别取0、20%、40%、60%、80%;通过添加Ti O2、可再生分散乳胶粉、甲基纤维素醚以及聚丙烯纤维改善防火砂浆性能。结果表明:两种粒径的砂浆强度、耐水性与导热性能均达到防火材料要求;相对于粒径0.5~4 mm气凝胶砂浆,0.5~2 mm气凝胶砂浆的28 d抗压强度、28d抗折强度和导热系数分别降低了32%、37%、7%,而软化系数提高了8%。扫描电镜SEM结果显示,0.5~2 mm气凝胶砂浆结构均匀疏松,更适用于制备隧道防火砂浆。
The influence rule of different particle sizes of the SiO2 aerogel played on the high performance concrete-special fire retardant coating mortar was tested, so was strength, resistance to water and heat conduetion performance.The design of mortar mix ratio was based on volume method,the total volume ＆the aerogel and sand was fixed to 60%,two kinds of particle size of commercial SiOz aerogel were used to replace the fine aggregate which are 0.5-2 mm and 0.5-4 mm and the replace rate were 0.20%. 40%, 60%, 80% respectively.The performance of fire retardant mortar has been improved through adding TiO2, renewable disperse latex powder, methyl cellulose ether and polypropylene fiber.The result was indicated that the strength, water resistance and thermal conductivity of two kinds of particle size of mortar meet the requirements of fireproof material.The 28 d compressive strength. 28 d flexural strength and thermal conductivity of aerogel mortar 0.5-2 mm were less 32%.37% and 7% than tt of aerogel mortar with 0.5-4 ram,while the softening coefficient of aerogel mortar with 0.5-2 mm was more 8% than that of aerogel mortar with 0.5-4 mm respectively.The structure of aerogel mortar with 0.5-2 mm is uniform and loose, and it is more suitable for the preparation of fire retardant mortar, alongside scanning electron microscopy （SEM） analyses.
出处
《混凝土》
CAS
北大核心
2017年第12期132-135,共4页
Concrete
基金
国家自然科学基金(51678080
51678081)
江苏省产学研合作前瞻性联合研究项目(BY2015027-23)
常州市社会发展项目(CE20155039)
关键词
隧道
防火砂浆
气凝胶
粒径
tunnel
fireproof mortar
aerogel
particle size
