粉煤灰对页岩陶砂轻集料砂浆性能的影响试验

Effect of Fly Ash on Performance of Shale Ceramisite Sand Light Aggregate Mortar

为探索粉煤灰页岩陶砂轻集料砂浆在隧道衬砌中的应用前景,采用内掺法配制了五种粉煤灰掺量的陶砂砂浆,测试了掺量对砂浆力学性能、抗冻性能、耐火性能,以及吸水率的影响.结果表明:粉煤灰可提高砂浆的强度,抗压和抗折强度随掺量的增加均先升高、后降低,二者对应的最佳掺量分别约为10%、5%;冻融循环和高温燃烧对砂浆的危害极大,粉煤灰可有效改其善抗冻性,掺量大于15%后改善效率显著下降,过火后砂浆强度损失可达92%,粉煤灰对改善耐火性能的作用有限,掺加粉煤灰后,强度损失率依然高达76%以上.另外,粉煤灰的掺加降低了砂浆的孔隙率,对吸声效果具有一定的负面影响.

In order to explore the application prospect of fly ash shale ceramisite sand light aggregate mortar in tunnel lining,five kinds of ceramic sand mortar with fly ash content were prepared by internal mixing method,and the effects of the content on the mechanical properties,frost resistance,fire resistance and water absorption of the mortar were tested.The results show that the strength of mortar can be improved by fly ash,and the compressive strength and flexural strength increase first and then decrease with the increase of fly ash content,and the corresponding optimal content is about 10%and 5%,respectively.Freeze-thaw cycle and high-temperature combustion do great harm to mortar,and fly ash can effectively improve its frost resistance.When the content of fly ash is more than 15%,the improvement efficiency decreases significantly,and the strength loss of mortar after fire can reach 92%.The effect of fly ash on improving fire resistance is limited.After adding fly ash,the strength loss rate is still as high as 76%.In addition,the addition of fly ash reduces the porosity of mortar,which has a certain negative impact on sound absorption.