摘要
软土承载力低,工程特性较差,无法直接作为地基进行工程建设,此外我国工业废渣产量巨大,且利用率较低,为推动高质量发展要求,本文采用粉煤灰作为前驱体,电石渣、硫酸钠作为激发剂,研究软土的固化机理与微观结构发展。结果表明,最优配合比为粉煤灰掺量17.3%(质量分数,下同)、电石渣掺量7.3%、硫酸钠掺量5.0%。最优配合比下固化土7和28 d无侧限抗压强度分别为2474.0和3134.0 kPa,与预测强度相比误差较小,响应面法优化配比具备有效性和科学性。固化土7和28 d水稳系数分别为0.73和0.85,固化土具有较好的抗水侵蚀能力。28 d固化土水化产物主要为水化硅酸钙(C-S-H)和钙矾石(AFt),二者填充、包裹固化土内部孔隙,固化土微观结构逐渐密实,力学性能得到提高。
Soft soil has low bearing capacity and poor engineering characteristics,so it can not be directly used as foundation for engineering construction.In addition,China’s industrial waste residue has a huge output and low utilization rate.In order to promote the requirements of high-quality development,this paper uses fly ash as precursor,carbide slag and sodium sulfate as activators to study the solidification mechanism and microstructure development of soft soil.The results show that the optimal mix ratio is 17.3%(mass fraction,the same below)of fly ash,7.3%of carbide slag and 5.0%of sodium sulfate.The 7 and 28 d unconfined compressive strength of solidified soil under the optimal ratio are 2474.0 and 3134.0 kPa,respectively,and the error is small compared with the predicted strength.The response surface method is effective and scientific to optimize the mix ratio.The water stability coefficients of solidified soil at 7 and 28 d are 0.73 and 0.85,respectively,indicating that the solidified soil has good water erosion resistance.The hydration products of 28 d solidified soil are mainly hydrated calcium silicate(C-S-H)and ettringite(AFt),which fill and wrap the internal pores of solidified soil.The microstructure of solidified soil is gradually dense and the mechanical properties are improved.
作者
张顶飞
吕启航
张鹏
朱珍
陈向南
曹吉昌
ZHANG Dingfei;LYU Qihang;ZHANG Peng;ZHU Zhen;CHEN Xiangnan;CAO Jichang(School of Civil Engineering,Qingdao University of Technology,Qingdao 266520,China;China Railway Communication and Signal Survey and Design Institute Co.,Ltd.,Beijing 100083,China;Technology and Industrialization Development Center of the Ministry of Housing and Urban Rural Development,Beijing 100083,China)
出处
《硅酸盐通报》
CAS
北大核心
2023年第8期2821-2829,2845,共10页
Bulletin of the Chinese Ceramic Society
基金
国家自然科学基金面上项目(42177167)。
关键词
地质聚合物
粉煤灰
电石渣
响应面法
配合比优化
geopolymer
fly ash
carbide slag
response surface method
mix ratio optimization
