铁道科学与工程学报2025，Vol.22Issue(3)：1039-1051,13.DOI:10.19713/j.cnki.43-1423/u.T20240710
水玻璃激发矿渣粉改良铁路路基黄土性能研究
Properties of railway subgrade loess improved by sodium silicate activated GGBS
摘要
Abstract
In order to solve the insufficient strength of raw loess directly used in railway subgrade filling,as well as the engineering problems associated with.Sodium silicate alkali was used to stimulate the base polymer of GGBS to improve the mechanical property of the Q3 loess exploited in Xi'an.Through the unconfined compressive strength test of 44 groups'improved loess samples cured under 3 d,7 d,14 d and 28 d respectively,as well as the compaction tests and direct shear test,the optimal dosage of slag powder and sodium silicate during single use or combined use were both obtained for engineering application under different curing period.Furthermore,the scanning electron microscopy tests,particle size analysis tests,XRD mineral fraction tests were combined with the mechanical ones to reveal the strengthen mechanism.The results show that the strength of these loess samples increase with the increasing curing period.The c value of the shear strength index of 7 days can increase to 91.9 kPa,31.7%higher than the one of raw loess when the ratio of silt particle is 80%.That is,the optimal mass ratio of loess to GGBS is 1:0.75.The value of φ increased to 32.1°.For the test combined the GGBS with the sodium silicate,with the decrease of sodium silicate modulus and the increase of alkali content,the compressive strength of sodium silicate induced GGBS solidified loess increase.The optimal sodium silicate dosage is 1.5%alkali content with 1.5 modulus.The compressive strength can reache to 14.9 MPa in 28 days,33.7 times higher than that of raw loess.The strengthen mechanism is summarized as follows.The sodium silicate can stimulate the GGBS to generate Calcium silicate(aluminate)gel(C(-A-)-S-H),which can make less and smaller pores,generate the inlay structure,and cement the loess skeleton particles and filled the intergranular pores,divide the bigger pores to smaller ones,make the channel narrower,connectivity poorer,finally improve the friction and bonding strength of the loess.It is engineering applicable,economical and environment friendly to use sodium silicate induced GGBS solidified loess in railway subgrade.关键词
水玻璃/矿渣粉/改良黄土/强度/固化机理Key words
sodium silicate/GGBS/improved loess/strength/strengthen mechanism分类
建筑与水利引用本文复制引用
贾能,贺礼..水玻璃激发矿渣粉改良铁路路基黄土性能研究[J].铁道科学与工程学报,2025,22(3):1039-1051,13.基金项目
陕西省自然科学基础研究计划(2021JQ-232) （2021JQ-232）
中央高校自然科学基金资助项目(300102280106) （300102280106）
长安大学教改项目(300108231142) （300108231142）
大学生创新创业训练计划项目(S202410710305) （S202410710305）
