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The use of fine portions from construction and demolition waste for Expansive soil stabilization: A review

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Frontiers of Structural and Civil Engineering 2022年第7期16卷 803-816页

作者： Mgboawaji Claude UJILE Samuel Jonah ABBEY Civil Engineering Faculty of Environment and TechnologyUniversity of the West of EnglandBristol BS161QYUK Geotechnical Engineering Faculty of Environment and TechnologyUniversity of the West of EnglandBristol BS161QYUK

Construction and demolition waste(CDW)are the largest waste products in the world today and competes as a viable recycled additive material in place of natural aggregates.Due to the increase in compressive strength of different mix proportions of CDW,it is also considered for reuse in concrete and subbase construction.This study shows the effect of CDW in Expansive soil stabilization.The chemical and mechanical properties of these materials have shown that they are capable of developing compressive strength properties for replacement of cement with significant reduction in carbon emission.The inherent compositional properties of recycled CDW compared in this review suggests that CDW have good filler properties in highly Expansive soils.Mixtures of crushed brick and recycled aggregates characterised based on chemical properties of different replacement ratios suggests that CDW of good-quality aggregates reduces swell potential of Expansive soils and increased mechanical strength in pavement construction.

关键词： mixed fine portions construction and demolition waste Expansive soil soil stabilization

Intermittent swelling and shrinkage of a highly Expansive soil treated with polyacrylamide

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第1期14卷 252-261页

作者： Amin Soltani An Deng Abbas Taheri Brendan C.O’Kelly School of Engineering Information Technology and Physical SciencesFederation UniversityChurchillVIC3842Australia School of Civil Environmental and Mining EngineeringThe University of AdelaideAdelaideSA5005Australia Department of Civil Structural and Environmental EngineeringTrinity College DublinDublinD02 PN40Ireland

This laboratory study examines the potential use of an anionic polyacrylamide(PAM)-based material as an environmentally sustainable additive for the stabilization of an Expansive soil from South Australia.The experimental program consisted of consistency limits,sediment volume,compaction and oedometer cyclic swell-shrink tests,performed using distilled water and four different PAM-to-water solutions of P_(D)=0.1 g/L,0.2 g/L,0.4 g/L and 0.6 g/L as the mixing liquids.Overall,the relative swelling and shrinkage strains were found to decrease with increasing number of applied swell-shrink cycles,with an‘elastic equilibrium’condition achieved on the conclusion of four cycles.The propensity for swelling/shrinkage potential reduction(for any given cycle)was found to be in favor of increasing the PAM dosage up to P_(D)=0.2 g/L,beyond which the excess PAM molecules self-associate as aggregates,thereby functioning as a lubricant instead of a flocculant;this critical dosage was termed‘maximum flocculation dosage’(MFD).The MFD assertion was discussed and validated using the consistency limits and sediment volume properties,both exhibiting only marginal variations beyond the identified MFD of P_(D)=0.2 g/L.The accumulated axial strain progressively transitioned from‘expansive’for the unamended soil to an ideal‘neutral’state at the MFD,while higher dosages demonstrated undesirable‘contractive’states.

关键词： Expansive soil Polyacrylamide(PAM) Consistency limits Sediment volume Swell-shrink cycles Swelling and shrinkage strains Accumulated axial strain

Improved Geotechnical Behavior of an Expansive soil Amended with Cationic Polyacrylamide

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Journal of Renewable Materials 2021年第11期9卷 1941-1957页

作者： Shengquan Zhou Minjie Shi Wei Chen Yongfei Zhang Weijian Wang Haojin Zhang Dongwei Li School of Civil Engineering and Architecture Anhui University of Science and TechnologyHuainan232001China School of Civil and Architectural Engineering East China University of TechnologyNanchang330013China

The characteristics of soil treated with cationic polyacrylamide(CPAM)mass content of 0%,0.2%,0.4%,0.6%,0.8%,and 1%were investigated through a series of laboratory tests to explore the practical engineering effect of an Expansive soil amended with environmental protection material CPAM.The results indicate that with the increasing CPAM content,the liquid limit and plasticity index of soil decrease,the plastic limit increases,and the free swelling ratio and loaded swelling ratio decrease.Besides,the improved soil has less disintegrating property and better water stability.The shear strength increases as the content increases,and the optimal content is 0.6%.Meanwhile,the cohesion of the soil first increases and then decreases,and the internal friction angle increases.Additionally,the unconfined compressive strength first increases and then decreases.The improved soil presents the characteristics of brittle failure and reaches the peak value(410.1 kPa)at the content of 0.8%after curing for 14 days.Scanning electron microscope(SEM)exhibits that the number of curved and wrinkled sections of the Expansive soil is reduced after CPAM improvement.Simultaneously,the arrangement of the superimposed polymer changes from face-face to side-angle or side-face-angle,and the reticular structure formed improves the strength and spatial stability of the soil.Therefore,adding appropriate cationic polyacrylamide could improve Expansive soil in engineering.

关键词： Expansive soil cationic polyacrylamide chemical modification laboratory tests microstructure

Expansive soil Stabilization by Bagasse Ash in Partial Replacement of Cement

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Journal of Renewable Materials 2023年第4期11卷 1911-1935页

作者： Waleed Awadalseed Honghua Zhao Hemei Sun Ming Huang Cong Liu State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsDalian University of TechnologyDalian116023China State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsInternational Research Center for Computational MechanicsDalian University of TechnologyDalian116023China Department of Geotechnical Engineering College of Civil EngineeringHunan UniversityChangsha410082China College of Civil Engineering Fuzhou UniversityFuzhou350116China

This study examined the effects of using bagasse ash in replacement of ordinary Portland cement(OPC)in the treatment of Expansive soils.The study concentrated on the compaction characteristics,volume change,compressive strength,splitting tensile strength,microstructure,California bearing ratio(CBR)value,and shear wave velocity of Expansive soils treated with cement.Different bagasse ash replacement ratios were used to create soil samples.At varying curing times of 7,14,and 28 days,standard compaction tests,unconfined compressive strength tests,CBR tests,Brazilian split tensile testing,and bender element(BE)tests were carried out.According to X-ray diffraction(XRD)investigations,quartz and crystobalite make up the majority of the minerals in bagasse ash.Bagasse ash contains a variety of grain sizes,including numerous fiber-shaped particles,according to a scanning electronic microscope(SEM)test.For all of the treated specimens with various replacement ratios,the overall additive content has not changed.The results of the Brazilian split tensile tests demonstrate improved tensile strength for all specimens with various replacement proportions.A lower maximum dry density and a greater optimal water content would result from the substitution of bagasse ash.When the replacement ratio is not more than 20%,the CBR values of the parts replaced specimens are even higher than the cement treatments.The results of BE testing on the treated soils show that there is significant stiffness anisotropy but that it steadily diminishes with curing time and replacement ratio.According to the study,bagasse ash is a useful mineral additive,and the best replacement ratio(CBA20)is 20%.

关键词： Expansive soil bagasse ash cement calcium silicate hydrate(CSH) stiffness anisotropy

Swelling pressure evolution characterization of strong Expansive soil considering the influence of reserved expansion deformation

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Journal of Mountain Science 2024年第1期21卷 252-270页

作者： LI Tianguo KONG Lingwei GUO Aiguo YAN Junbiao State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China

Numerous engineering cases have demonstrated that the Expansive soil channel slope remains susceptible to damage with the implementation of a rigid or closed protective structure. It is common for the protective structure to experience bulging failure due to excessive swelling pressure. To investigate the swelling pressure properties of Expansive soil, the constant volume test was employed to study the influence of water content and reserved expansion deformation on the characteristics of swelling pressure in strong Expansive soils, and also to explore the evolution mechanism of the swelling pressure. The findings demonstrate that the swelling pressure-time curve can be classified into swelling pressure-time softening and swelling pressure-time stability type. The swelling pressuretime curve of the specimen with low water content is the swelling pressure-time softening type, and the softening level will be weakened with increasing reserved expansion deformation. Besides, the maximum swelling pressure Psmax decreases with increasing water content and reserved expansion deformation, especially for expansion ratio η from 24% to 37%. The reserved deformation has little effect on reducing Psmax when it is beyond 7% of the expansion rate. The specimen with low water content has a more homogeneous structure due to the significant expansion-filling effect, and the fracture and reorganization of the aggregates in the specimens with low water content cause the swelling pressure-time softening behavior. In addition, the proposed swelling pressure-time curve prediction model has a good prediction on the test results. If necessary, a deformation space of about 7% expansion rate is recommended to be reserved in the engineering to reduce the swelling pressure except for keeping a stable water content.

关键词： Expansive soil Swelling pressure Reserved expansion deformation Water content

Fly Ash/Paraffin Composite Phase Change Material Used to Treat Thermal and Mechanical Properties of Expansive soil in Cold Regions

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Journal of Renewable Materials 2022年第4期10卷 1153-1173页

作者： Yong Chen Yinghao Huang Min Wu Shuo Wang Geotechnical Engineering Department Nanjing Hydraulic Research InstituteNanjing210024China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Science Nanjing210029China

Phase change materials(PCMs)can store large amounts of energy in latent heat and release it during phase changes,which could be used to improve the freeze-thaw performance of soil.The composite phase change material was prepared with paraffin as the PCM and 8%Class C fly ash(CFA)as the supporting material.Laboratory tests were conducted to reveal the influence of phase change paraffin composite Class C fly ash(CFA-PCM)on the thermal properties,volume changes and mechanical properties of Expansive soil.The results show that PCM failed to establish a good improvement effect due to leakage.CFA can effectively adsorb phase change materials,and the two have good compatibility.CFA-PCM reduces the volume change and strength attenuation of the soil,and 8 wt.%PCM is the optimal content.CFA-PCM turns the phase change latent heat down of the soil and improves its thermal stability.CFA-PCM makes the impact small of freeze-thaw on soil pore structure damage and improves soil volume change and mechanical properties on a macroscopic scale.In addition,CFA-8 wt.%PCM treated Expansive soil has apparent advantages in resisting repeated freeze-thaw cycles,providing a reference for actual engineering design.

关键词： Composite phase change material freeze-thaw performance Expansive soil thermal properties mechanical properties

Weak Expansive soil Physical Properties Modification by Means of a Cement-Jute Fiber

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Fluid Dynamics & Materials Processing 2023年第8期19卷 2119-2130页

作者： Zisheng Yang Wendong Li Xuelei Cheng Ran Hai Shunqun Li School of Architectural and Civil Engineering Zhongyuan University of TechnologyZhengzhou450007China Yellow River Institute of Hydraulic Research Zhengzhou450003China School of Civil Engineering Tianjin Chengjian UniversityTianjin300384China

Sixteen groups of comprehensive tests have been conducted to investigate the modifications in the physical properties of a weak Expansive soil due to the addition of a cement jute fiber.The tests have been conducted to analyze the liquid plastic limit,the particle distribution and the free expansion rate.The results show that:(1)With an increase in the cement-jute fiber content,the free expansion rate of the modified Expansive soil gradually decreases,however,such a rate rebounds when the fiber content exceeds 0.5%and the cement content exceeds 6%.(2)With an increase in the cement percentage,the particle unevenness coefficient(Cu)and curvature coefficient(Cc)of the modified Expansive soil tend to grow gradually.The Cc coefficient reaches 1.0 when the cement content is 6%.The unevenness coefficient of 16 soil samples is greater than 5.0,however,the Cu coefficient decreases when the cement content reaches 6%.(3)The plastic limit of soil increases as the cement content is made higher,while the liquid limit and plastic index decrease gradually.When the content of the modified material is 2%+0.1%~2%+0.7%(Cement content+jute fiber content),the change of particle size distribution is most obvious.(4)When the contents of cement and jute fiber are is 6%and 0.5%,respectively,the modification induced in the physical properties of soil samples corresponds to the best case.

关键词： Cement jute fiber Expansive soil expansion optimal dosage

Engineering Properties of Expansive soil

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Journal of Wuhan University of Technology(Materials Science) 2005年第2期20卷 109-110页

作者：戴绍斌 Institute of Architecture Design and Research Wuhan University of TechnologyWuhan 430070China Assoc.Prof

The components of Expansive soil were analyzed with EDAX, and it is shown that the main contents of Expansive soil in the northern Hubei have some significant effects on engineering properties of Expansive soil. Furthermore, the soil modified by lime has an obvious increase of Ca^(2+) and an improvement of connections between granules so as to reduce the expansibility and contractility of soil. And it also has a better effect on the modified Expansive soil than the one modified by pulverized fuel ash.

关键词： Expansive soil engineering property mineral composition chemical component

Dynamic characteristics of lime-treated Expansive soil under cyclic loading

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Journal of Rock Mechanics and Geotechnical Engineering 2012年第4期4卷 352-359页

作者： Min Wang Lingwei Kong Chong Zhao Meng Zang State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of Sciences

To better understand the dynamic properties of expansive clay treated with lime, a series of laboratory tests were conducted using a dynamic triaxial test system. The influential factors, including moisture content, confining pressure, vibration frequency, consolidation ratio, and cycle number on the dynamic characteristics were discussed. Experimental results indicate that specimens at low moisture contents tend to damage along the 30~ shear plane and they present brittle failure, while saturated specimens show swelling phenomenon and plastic failure. A redtiction in cohesion has been observed for unsaturated samples at large number of cycles, while it is opposite for the internal friction angle. For the saturated specimens, both the cohesion and internal friction angle decrease with increasing number of cycles.

关键词： Expansive soil lime-treated soil dynamic characteristics low lime proportion