摘要
废弃黏土工程特性较差,难以作为路基材料进行资源化利用,还有工业废渣的产量日益增长,其利用率根本追不上产量,针对该问题研究了不同掺量矿渣-脱硫石膏-电石渣(GGBS-DG-CCS,GDC)固化剂对黏土力学性能和微观机理的影响。采用Design Expert中的box-behnken design(BBD)得出矿渣、脱硫石膏、电石渣的最佳配合比,通过无侧限抗压强度、劈裂抗拉强度和水稳试验评价了GDC固化土的宏观力学性能;然后采用SEM和XRD分析了GDC固化剂与黏土之间的相互作用机理,并与同掺量的传统水泥固化方案进行对比。结果表明:矿渣、脱硫石膏、电石渣的最佳配合比为11.93︰1.53︰6.01,GDC固化黏土的无侧限抗压强度均随固化剂掺量和养护龄期的增加而增大;相较于水泥固化土,GDC固化土具有更好的水稳定性,且随着养护龄期的增长,GDC固化土呈现出更高的抗压强度、抗劈裂性以及更低的脆性;SEM和XRD分析显示,GDC固化土在养护过程中会不断生成水化硅酸钙(C-S-H)、水化铝酸钙(C-A-H)等胶凝性水化物以及膨胀性水化产物钙矾石(Aft),与水泥土相比,28 d龄期的GDC固化土微观结构更密实,水化产物的覆盖范围更广。GDC固化剂对废弃黏土改性效果显著,具有较好应用前景。
The waste clay has poor engineering properties and is difficult to be used as subgrade material for resource utilization.This paper studies the effects of different amounts of ground granulated blast furnace slag-desulfurization gypsum-calcium carbide slag(GDC)soil stabilizer on the mechanical properties and micro mechanism of marine clay.Firstly,the unconfined compressive strength,splitting tensile strength and water stability tests were used to evaluate the macroscopic mechanical properties of GDC solidified soil.Then the interaction mechanism between the curing agent and marine clay was analyzed by SEM and XRD,and compared with the traditional cement curing scheme with the same content.The results show that the unconfined compressive strength of GDC solidified clay and cement solidified clay increases with the increase of curing agent content and curing age.Compared with cement solidified soil,GDC solidified soil has better water stability.With the growth of curing age,GDC solidified soil shows higher compressive strength,splitting resistance and lower brittleness;SEM and XRD analysis shows that GDC solidified soil would continuously generate cementitious hydrates such as hydrated calcium silicate(C-S-H),hydrated calcium aluminate(C-A-H)and expansive hydrated product ettringite(Aft)during curing,which can effectively wrap and connect clay particles and fill soil micro pores.Compared with cement stabilized soil,GDC solidified soil at the age of 28 days has a denser microstructure and a wider coverage of hydrated products.GDC soil stabilizer has remarkable effect on the modification of waste marine clay and has a good application prospect.
作者
金胜赫
王修山
吴越鹏
KIM Sunghyok;WANG Xiushan;WU Yuepeng(School of Architectural and Civil Engineering,Zhejiang Sci-Tech University,Hangzhou 310018,China;Faculty of Resources Probing Engineering,Kim Chaek University of Technology,Pyongyang 999093,D.P.R.Korea)
出处
《工程地质学报》
CSCD
北大核心
2023年第2期397-408,共12页
Journal of Engineering Geology
基金
浙江省自然科学基金项目(资助号:LGF22E080016)。
关键词
固化黏土
工业废渣
固化剂
道路工程
无侧限抗压强度
Solidified clay
Industrial waste residue
Soil stabilizer
Highway engineering
Unconfined compressive strength
