水泥粉煤灰改良盐渍土最优配比研究  

Study on the Optimal Ratio of Cement Coal Fly Ash Improved Saline Soil

作　　者：訾亚丹 崔宏环[1,2] ZI Yadan;CUI Honghuan(Hebei University of Architecture,Zhangjiakou 075000,China;Civil Engineering Diagnosis of Hebei Province,Key Laboratory for Reconstruction and Disaster Resistance,Zhangjiakou 075000,China)

机构地区：[1]河北建筑工程学院,河北张家口075000 [2]河北省土木工程诊断、改造与抗灾重点实验室,河北张家口075000

出　　处：《河南科技》2024年第7期52-57,共6页Henan Science and Technology

摘　　要：【目的】在传统水泥改良土的基础上加入粉煤灰复合改良盐渍土,粉煤灰固化盐渍土与“双碳”目标契合,具有积极的意义。【方法】设计三因素四水平正交试验分析改良剂掺量、养护条件、含水率对试样抗压强度及弹性模量的影响。控制水泥粉煤灰固定比例为1∶2,掺量及含水率水平为12%、14%、16%、18%,养护方式分别为清水、盐水、高温养护及标准养护。【结果】通过击实试验可得试验范围内水泥粉煤灰掺量对最大干密度的影响不大,最大干密度约为1.8 g/cm^(3),最优含水率介于14%~16%之间。改良土呈应变软化型,7 d及14 d龄期不同组别抗压强度最高为1.69 MPa、1.99 MPa,最小为0.34 MPa、0.55 MPa。【结论】试样随着掺量增大及火山灰反应、水化程度的加深应变软化特征明显;改良剂掺量为18%、含水率为16%、养护方式为高温养护时强度最大,三个因素对盐渍土强度的影响排序依次为养护条件>改良剂掺量>含水率,因素影响权重分别为养护条件57%、改良剂掺量24%、含水率19%;将抗压强度与回弹模量进行拟合,发现二者具有良好的线性关系。[Purposes]On the basis of traditional cement improved soil,fly ash is added to improve saline soil.Fly ash solidified saline soil is in line with the goal of“double carbon”goal,which has positive significance.[Methods]A three-factor and four-level orthogonal test was designed to analyze the effects of cement fly-ash content,curing conditions and water content on the compressive strength and elastic modulus of the sample.The fixed proportion of cement fly ash is controlled to be 1∶2,the content t levels are 12%,14%,16%,18%,and the curing methods are clean water,salt water,high temperature curing and standard curing.[Findings]The compaction test showed that the content of cement fly-ash had little effect on the maximum dry density within the test range,the maximum dry density was about 1.8 g/cm^(3),and the optimal water content was between 14%and 16%.The improved soil shows strain softening type.The highest compressive strength is 1.69 MPa and 1.99 MPa,and the smallest compressive strength is 0.34 MPa and 0.55 MPa at 7 d and 14 d ages.[Conclusions]The strain softening characteristics are obvious with the increase of dosage and the deepening of reaction and hydration degree of volcanic ash.The amendment content is 18%,the moisture content is 16%,and the strength is the highest when the curing method is high temperature curing.The strength of saline soil is the largest when the dosage of modifier is 18%,the moisture content is 16%,and the curing method is high temperature curing.The order of the influence of the three factors on the strength of saline soil is curing condition>modifier dosage>moisture content.The weight of the factors is 57%of curing condition,24%of modifier dosage and 19%of moisture content.The compressive strength and resilient modulus are fitted,and it is found that there is a good linear relationship between them.

关 键 词：盐渍土 水泥粉煤灰改良 正交试验 无侧限抗压强度 

分 类 号：TU448[建筑科学—岩土工程]