Experimental Study on the Strength Characteristics of Modified Guilin Red Clay

To address the engineering challenges associated with Guilin red clay, such as its potentially low strength and unfavorable mechanical behavior, this study investigated the effectiveness of lignin and lime as modifiers. Consolidation undrained triaxial tests and scanning electron microscopy (SEM) we...

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Main Authors: Wenwu Chen, Zhigao Xie, Jiguang Chen, Mengyao Hong, Xiaobo Wang, Haofeng Zhou, Bai Yang
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Buildings
Subjects:
Online Access:https://www.mdpi.com/2075-5309/15/14/2533
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author Wenwu Chen
Zhigao Xie
Jiguang Chen
Mengyao Hong
Xiaobo Wang
Haofeng Zhou
Bai Yang
author_facet Wenwu Chen
Zhigao Xie
Jiguang Chen
Mengyao Hong
Xiaobo Wang
Haofeng Zhou
Bai Yang
author_sort Wenwu Chen
collection DOAJ
description To address the engineering challenges associated with Guilin red clay, such as its potentially low strength and unfavorable mechanical behavior, this study investigated the effectiveness of lignin and lime as modifiers. Consolidation undrained triaxial tests and scanning electron microscopy (SEM) were employed to evaluate the strength characteristics and microstructural changes in modified clay specimens with varying dosages. The results demonstrate distinct strengthening mechanisms: Lignin exhibits an optimal dosage (6%), significantly increasing cohesion and internal friction angle through physical reinforcement (“soil fiber” formation), but higher dosages (8%) lead to particle separation and strength reduction. In contrast, lime provides continuous and substantial strength enhancement with increasing dosage (up to 8%), primarily through chemical reactions producing cementitious compounds (e.g., C-S-H, C-A-H) that densify the structure. Consequently, lime-modified clay shows significantly higher cohesion and internal friction angle compared to lignin-modified clay at equivalent or higher dosages, with corresponding stress–strain curves shifting from enhanced (strain-hardening) to softening behavior. These findings provide practical insights into red clay improvement in geotechnical engineering applications.
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series Buildings
spelling doaj-art-146723cefa8b450ca31a2a995df302912025-08-20T03:08:10ZengMDPI AGBuildings2075-53092025-07-011514253310.3390/buildings15142533Experimental Study on the Strength Characteristics of Modified Guilin Red ClayWenwu Chen0Zhigao Xie1Jiguang Chen2Mengyao Hong3Xiaobo Wang4Haofeng Zhou5Bai Yang6School of Architecture and Transportation Engineering, Guilin University of Electronic Technology, Guilin 541004, ChinaSchool of Architecture and Transportation Engineering, Guilin University of Electronic Technology, Guilin 541004, ChinaSchool of Architecture and Transportation Engineering, Guilin University of Electronic Technology, Guilin 541004, ChinaSchool of Architecture and Transportation Engineering, Guilin University of Electronic Technology, Guilin 541004, ChinaSichuan Road & Bridge Group Co., Ltd., Chengdu 610041, ChinaSchool of Architecture and Transportation Engineering, Guilin University of Electronic Technology, Guilin 541004, ChinaSchool of Architecture and Transportation Engineering, Guilin University of Electronic Technology, Guilin 541004, ChinaTo address the engineering challenges associated with Guilin red clay, such as its potentially low strength and unfavorable mechanical behavior, this study investigated the effectiveness of lignin and lime as modifiers. Consolidation undrained triaxial tests and scanning electron microscopy (SEM) were employed to evaluate the strength characteristics and microstructural changes in modified clay specimens with varying dosages. The results demonstrate distinct strengthening mechanisms: Lignin exhibits an optimal dosage (6%), significantly increasing cohesion and internal friction angle through physical reinforcement (“soil fiber” formation), but higher dosages (8%) lead to particle separation and strength reduction. In contrast, lime provides continuous and substantial strength enhancement with increasing dosage (up to 8%), primarily through chemical reactions producing cementitious compounds (e.g., C-S-H, C-A-H) that densify the structure. Consequently, lime-modified clay shows significantly higher cohesion and internal friction angle compared to lignin-modified clay at equivalent or higher dosages, with corresponding stress–strain curves shifting from enhanced (strain-hardening) to softening behavior. These findings provide practical insights into red clay improvement in geotechnical engineering applications.https://www.mdpi.com/2075-5309/15/14/2533red clayligninlimestrength characteristicsmicrostructure
spellingShingle Wenwu Chen
Zhigao Xie
Jiguang Chen
Mengyao Hong
Xiaobo Wang
Haofeng Zhou
Bai Yang
Experimental Study on the Strength Characteristics of Modified Guilin Red Clay
Buildings
red clay
lignin
lime
strength characteristics
microstructure
title Experimental Study on the Strength Characteristics of Modified Guilin Red Clay
title_full Experimental Study on the Strength Characteristics of Modified Guilin Red Clay
title_fullStr Experimental Study on the Strength Characteristics of Modified Guilin Red Clay
title_full_unstemmed Experimental Study on the Strength Characteristics of Modified Guilin Red Clay
title_short Experimental Study on the Strength Characteristics of Modified Guilin Red Clay
title_sort experimental study on the strength characteristics of modified guilin red clay
topic red clay
lignin
lime
strength characteristics
microstructure
url https://www.mdpi.com/2075-5309/15/14/2533
work_keys_str_mv AT wenwuchen experimentalstudyonthestrengthcharacteristicsofmodifiedguilinredclay
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AT jiguangchen experimentalstudyonthestrengthcharacteristicsofmodifiedguilinredclay
AT mengyaohong experimentalstudyonthestrengthcharacteristicsofmodifiedguilinredclay
AT xiaobowang experimentalstudyonthestrengthcharacteristicsofmodifiedguilinredclay
AT haofengzhou experimentalstudyonthestrengthcharacteristicsofmodifiedguilinredclay
AT baiyang experimentalstudyonthestrengthcharacteristicsofmodifiedguilinredclay