摘要
本工作采用废弃砖粉和循环流化床固硫灰协同制备新型路基稳定材料,对其力学、收缩及抗冻等性能进行了系统研究。结果表明,在按m(砖粉)∶m(粉煤灰)=1∶2-1∶4、m(结合料)∶m(混合料)=20∶80-15∶85的要求设计的实验条件下新型路基材料7 d无侧限抗压强度优于石灰粉煤灰基准样。随着砖粉掺量的增加,路基稳定材料的力学性能和耐久性能呈现出先提高后下降的趋势,但都优于标准规定值。当砖粉掺量为30%、固硫灰掺量为70%(均为质量分数)时,新型路基稳定材料的力学、收缩和冻融性能最优。通过XRD、SEM和TGA等方法分析各方案下新型路基材料水化产物的矿物组成、微观形貌和热失重特性,研究多固废协同作用机理。结果表明,在砖粉协同固硫灰制备的新型路基材料中生成的水化产物有钙钒石、水化硅酸钙及碳酸钙,这些水化产物可为新型路基稳定材料提供强度。
In this work, waste brick powder and circulating fluidized bed solid sulfur ash are used to prepare a new roadbed stabilization material synergistically, and its mechanical, shrinkage and frost resistance properties were systematically studied. The results show that the 7 d unconfined compressive strength of the new roadbed material is better than that of the lime-fly ash reference sample, under the experimental ratios designed according to the requirements of m(brick dust): m(fly ash)=1∶2-1∶4 and m(binding material): m(mixture)=20∶80-15∶85, and the mechanical properties and durability of the roadbed stabilization material show a trend of increasing and then decreasing with the increase of brick dust dosing, but they are better than the standard specified values. When the brick dust dosing is 30% and the stable sulfur ash dosing is 70%(both are mass fractions), the mechanical, shrinkage and freeze-thaw properties of new roadbed stabilization materials were optimal. XRD SEM and TGA methods were used to analyze the mineral composition, microstructure and thermal weight loss characteristics of each scheme’s new roadbed materials’ hydration products, and the synergistic mechanism of multi-solid waste was studied. The results show that the hydration products generate in the new roadbed materials prepared by the synergistic sulfur ash fixation of brick powder were as follows: ettringite, calcium silicate hydrate and calcium carbonate;these hydration products provide strength for new road base stabilization materials.
作者
张瑞
刘文欢
张浩
李辉
ZHANG Rui;LIU Wenhuan;ZHANG Hao;LI Hui(College of Materials Science and Engineering,Xi'an University of Architecture&Technology,Xi'an 710055,China;Shaanxi Ecological Cement&Concrete Engineering Technology Research Center,Xi'an 710055,China;Ecological Cement Engineering Research Center of Ministry of Education,Xi'an 710055,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2022年第12期112-118,共7页
Materials Reports
基金
榆林市科技计划项目(CXY⁃2020⁃059)。
关键词
废弃砖粉
固硫灰
路基材料
水化机理
waste brick powder
sulfur⁃fixing ash
subgrade material
hydration mechanism
