摘要
为研究水玻璃模数对粉煤灰地聚物强度和凝结性能的影响,文中进行初终凝试验、无侧限抗压强度试验和微观试验,分析了不同模数(1.0、1.5、2.0、2.5、3.0)水玻璃对粉煤灰地聚物凝结时间和无侧限抗压强度性能的影响。结果表明:(1)水玻璃模数为2.0时,粉煤灰地聚物的凝结时间最短;水玻璃模数在1.0~1.5时,试样的无侧限抗压强度较高,水玻璃模数超过2.0时,与峰值强度相比其无侧限抗压强度降低约90%。为保证粉煤灰地聚物凝结时间较短且无侧限抗压强度较高,结合初终凝试验和无侧限抗压强度试验结果,宜选择的水玻璃模数为1.0~2.0;(2)水玻璃模数越低,试样内部结构相对密实,颗粒与水化产物的粘结程度越强,所能承受的抗压强度越大;(3)从微观定量参数发现,当试样的养护龄期越长且水玻璃模数越小,地聚物内部孔隙形态越圆滑;试样的养护龄期越长,内部颗粒间的排列变得无序,水玻璃模数越大,对内部各物质间聚合的抑制作用更为明显。研究结论为粉煤灰地聚物作为注浆材料提供试验依据,对粉煤灰的利用和推广具有一定的指导意义。
In order to study the effects of sodium silicate modulus on the strength and setting properties of fly ash geopolymer,the effects of sodium silicate with different moduli(1.0,1.5,2.0,2.5 and 3.0)on the setting time and unconfined compressive strength properties of fly ash geopolymer are analyzed by carrying out initial and final setting test,unconfined compressive strength test and microscopic test.The results show that:(1)The setting time of fly ash geopolymer is the shortest when the sodium silicate modulus is 2.0;the compressive strength of the sample is higher when the modulus is 1.0~1.5.Its unconfined compressive strength is about 90%lower than the peak strength with the modulus exceeding 2.0.In order to ensure short setting time and high unconfined compressive strength of fly ash geopolymer,the sodium silicate modulus should be 1.0~2.0 in combination with the results of the initial and final setting test and unconfined compressive strength test;(2)The lower the modulus of sodium silicate,the denser the internal structure of the sample is.The stronger the bonding degree between particles and hydration products,the greater the compressive strength they can bear;(3)According to the microscopic quantitative parameters,the longer the curing age of the sample and the smaller the modulus,the smoother the pores inside the geopolymer is;the arrangement of internal particles becomes disordered with longer curing age of the sample.The larger the modulus of sodium silicate,the more significant the inhibition effect on the polymerization of internal substances is.The research provides experimental basis for fly ash geopolymer as grouting material,which has certain guiding significance for the application and promotion of fly ash.
作者
解邦龙
张吾渝
孙翔龙
崔靖俞
XIE Banglong;ZHANG Wuyu;SUN Xianglong;CUI Jingyu(School of Civil Engineering,Qinghai University,Key Laboratory of Energysaving Building Materials and Engineering Safety,Xining 810016,China)
出处
《青海大学学报》
2021年第5期77-84,共8页
Journal of Qinghai University
基金
青海省科学技术厅项目(2020-ZJ-738)
国家自然科学基金项目(51768060)。
关键词
粉煤灰
水玻璃
模数
微观定量参数
fly ash
sodium silicate
modulus
micro quantitative parameters
