Mechanical properties of saline soil solidified with lime, fly ash and modified polyvinyl alcohol under freeze-thaw cycles

The repeated freeze-thaw cycles with seasonal alternations have an obvious effect on soil structure. To reduce the temperature sensitivity of saline soil and then use it in engineering, a combined treatment method is proposed, where lime, fly ash and modified polyvinyl alcohol (MPA) are used as soli...

Full description

Bibliographic Details
Main Authors: LI Min, YU He-miao, DU Hong-pu, CAO Bao-yu, CHAI Shou-xi
Format: Article
Language:English
Published: SCIENCE PRESS , 16 DONGHUANGCHENGGEN NORTH ST, BEIJING, PEOPLES R CHINA, 100717 2022-02-01
Series:Rock and Soil Mechanics
Subjects:
Online Access:http://rocksoilmech.whrsm.ac.cn/EN/10.16285/j.rsm.2021.5132
_version_ 1811303824605839360
author LI Min
YU He-miao
DU Hong-pu
CAO Bao-yu
CHAI Shou-xi
author_facet LI Min
YU He-miao
DU Hong-pu
CAO Bao-yu
CHAI Shou-xi
author_sort LI Min
collection DOAJ
description The repeated freeze-thaw cycles with seasonal alternations have an obvious effect on soil structure. To reduce the temperature sensitivity of saline soil and then use it in engineering, a combined treatment method is proposed, where lime, fly ash and modified polyvinyl alcohol (MPA) are used as solidified materials. Unconfined compressive strength (UCS) tests and microstructure characterization are firstly used to evaluate the solidified effect and obtain the parameters range of solidified materials. Then, the shear strength tests for determining cohesion and internal friction angle are conducted. Experiments are conducted by considering separate and combined treatments of materials mentioned above. The results indicate that the combined treatment with lime, fly ash and MPA can improve the strength of saline soil. After combined treatment, the UCS is 1130.25 kPa, which is 5.18 times than that of saline soil (218 kPa). The strength of combined solidified saline soil meets the requirements of engineering specification (JTG 3430-2020). The stable value of UCS of combined solidified saline soil is 700 kPa under freeze-thaw cycles. The fluctuation is about 5% after three freeze-thaw cycles. The cohesion and the internal friction angle of combined solidified saline under the optimal proportion can be 208.2 kPa and 38.56°, respectively after three freeze-thaw cycles. The sensitivity of the factors is in an order of decreasing importance: curing time, lime content, MPA content, dry density, salt content, and freeze-thaw cycles. With an increase of lime, fly ash and MPA content, the strength of combined solidified saline soil increases and then tends to become stable. The optimization of solidification parameters can effectively weaken the influence of freeze-thaw on coastal saline soil. Based on tests results of compressive strength and shear strength, it can be concluded that the optimal combination of solidified parameters is 14% of lime, 30% of fly ash, 1% of MPA, 28 days of curing time, and a dry density of 1.65 g/cm3.
first_indexed 2024-04-13T07:55:04Z
format Article
id doaj.art-b9073f7c510c44139b12ba8f0ceed6fc
institution Directory Open Access Journal
issn 1000-7598
language English
last_indexed 2024-04-13T07:55:04Z
publishDate 2022-02-01
publisher SCIENCE PRESS , 16 DONGHUANGCHENGGEN NORTH ST, BEIJING, PEOPLES R CHINA, 100717
record_format Article
series Rock and Soil Mechanics
spelling doaj.art-b9073f7c510c44139b12ba8f0ceed6fc2022-12-22T02:55:26ZengSCIENCE PRESS , 16 DONGHUANGCHENGGEN NORTH ST, BEIJING, PEOPLES R CHINA, 100717Rock and Soil Mechanics1000-75982022-02-0143248949810.16285/j.rsm.2021.5132Mechanical properties of saline soil solidified with lime, fly ash and modified polyvinyl alcohol under freeze-thaw cyclesLI Min0YU He-miao1DU Hong-pu2CAO Bao-yu3CHAI Shou-xi4School of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, ChinaSchool of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, ChinaRadio and Television Henan Network Co., Ltd, Zhengzhou, Henan 450046, ChinaSchool of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, China School of Geology and Geomatics, Tianjin Chengjian University, Tianjin 300384, ChinaThe repeated freeze-thaw cycles with seasonal alternations have an obvious effect on soil structure. To reduce the temperature sensitivity of saline soil and then use it in engineering, a combined treatment method is proposed, where lime, fly ash and modified polyvinyl alcohol (MPA) are used as solidified materials. Unconfined compressive strength (UCS) tests and microstructure characterization are firstly used to evaluate the solidified effect and obtain the parameters range of solidified materials. Then, the shear strength tests for determining cohesion and internal friction angle are conducted. Experiments are conducted by considering separate and combined treatments of materials mentioned above. The results indicate that the combined treatment with lime, fly ash and MPA can improve the strength of saline soil. After combined treatment, the UCS is 1130.25 kPa, which is 5.18 times than that of saline soil (218 kPa). The strength of combined solidified saline soil meets the requirements of engineering specification (JTG 3430-2020). The stable value of UCS of combined solidified saline soil is 700 kPa under freeze-thaw cycles. The fluctuation is about 5% after three freeze-thaw cycles. The cohesion and the internal friction angle of combined solidified saline under the optimal proportion can be 208.2 kPa and 38.56°, respectively after three freeze-thaw cycles. The sensitivity of the factors is in an order of decreasing importance: curing time, lime content, MPA content, dry density, salt content, and freeze-thaw cycles. With an increase of lime, fly ash and MPA content, the strength of combined solidified saline soil increases and then tends to become stable. The optimization of solidification parameters can effectively weaken the influence of freeze-thaw on coastal saline soil. Based on tests results of compressive strength and shear strength, it can be concluded that the optimal combination of solidified parameters is 14% of lime, 30% of fly ash, 1% of MPA, 28 days of curing time, and a dry density of 1.65 g/cm3.http://rocksoilmech.whrsm.ac.cn/EN/10.16285/j.rsm.2021.5132mechanical propertyfreeze-thaw performancecombined treatment methodcompressive strengthshear strengthmicrostructuresaline soil
spellingShingle LI Min
YU He-miao
DU Hong-pu
CAO Bao-yu
CHAI Shou-xi
Mechanical properties of saline soil solidified with lime, fly ash and modified polyvinyl alcohol under freeze-thaw cycles
Rock and Soil Mechanics
mechanical property
freeze-thaw performance
combined treatment method
compressive strength
shear strength
microstructure
saline soil
title Mechanical properties of saline soil solidified with lime, fly ash and modified polyvinyl alcohol under freeze-thaw cycles
title_full Mechanical properties of saline soil solidified with lime, fly ash and modified polyvinyl alcohol under freeze-thaw cycles
title_fullStr Mechanical properties of saline soil solidified with lime, fly ash and modified polyvinyl alcohol under freeze-thaw cycles
title_full_unstemmed Mechanical properties of saline soil solidified with lime, fly ash and modified polyvinyl alcohol under freeze-thaw cycles
title_short Mechanical properties of saline soil solidified with lime, fly ash and modified polyvinyl alcohol under freeze-thaw cycles
title_sort mechanical properties of saline soil solidified with lime fly ash and modified polyvinyl alcohol under freeze thaw cycles
topic mechanical property
freeze-thaw performance
combined treatment method
compressive strength
shear strength
microstructure
saline soil
url http://rocksoilmech.whrsm.ac.cn/EN/10.16285/j.rsm.2021.5132
work_keys_str_mv AT limin mechanicalpropertiesofsalinesoilsolidifiedwithlimeflyashandmodifiedpolyvinylalcoholunderfreezethawcycles
AT yuhemiao mechanicalpropertiesofsalinesoilsolidifiedwithlimeflyashandmodifiedpolyvinylalcoholunderfreezethawcycles
AT duhongpu mechanicalpropertiesofsalinesoilsolidifiedwithlimeflyashandmodifiedpolyvinylalcoholunderfreezethawcycles
AT caobaoyu mechanicalpropertiesofsalinesoilsolidifiedwithlimeflyashandmodifiedpolyvinylalcoholunderfreezethawcycles
AT chaishouxi mechanicalpropertiesofsalinesoilsolidifiedwithlimeflyashandmodifiedpolyvinylalcoholunderfreezethawcycles