Investigation of the Effects of Two Different Biopolymers on the Strength Parameters of Silty Soil

Öz

Soil improvement methods are commonly employed to enhance the load-bearing capacity of weak soils. Due to environmental concerns, traditional additives like lime and cement are increasingly being replaced by more sustainable alternatives. Recently, biopolymers have gained attention as environmentally friendly options for soil stabilization. However, combining biopolymers with additional agents to enhance bond strength is rare. This study investigates the effects of using Guar Gum and Xanthan Gum biopolymers in combination with Calcium Chloride (CaCl₂) on the strength parameters of silty soil. Biopolymers are known to form gel-like structures between soil particles, increasing strength. At the same time, Calcium Chloride interacts with the carboxyl groups of biopolymers, creating cross-linkages that further improve soil strength. In this research, biopolymers and Calcium Chloride were combined with silty soil and subjected to 7,28,56 and 90 days of curing. Unconfined compressive strength (UCS) and direct shear tests were conducted, and the results were compared with reference samples. Changes in internal friction angle and cohesion were also analyzed based on different biopolymer ratios. The results demonstrated significant improvements in the strength of long-term cured samples, with Calcium Chloride enhancing the cross-linking effect of biopolymers. These findings suggest that biopolymers, in combination with Calcium Chloride, can be effective in environmentally friendly soil stabilization projects.

Anahtar Kelimeler

• Biopolymer
• Soil stabilization
• Xanthan gum
• Guar gum
• Cross-linking

İki Farklı Biyopolimerin Siltli Zemin Dayanım Parametreleri Üzerindeki Etkilerinin Araştırılması

Öz

Zemin iyileştirme yöntemleri zayıf zeminlerin taşıma gücünü artırmak için yaygın olarak kullanılır. Çevresel kaygılar nedeniyle kireç ve çimento gibi geleneksel katkı maddeleri, yerini giderek daha sürdürülebilir alternatiflere bırakmaktadır. Son zamanlarda, biyopolimerler zemin iyileştirme amacıyla, çevre dostu seçenekler olarak dikkat çekmektedir. Ancak, zemin ve biyopolimer arasında oluşan bağların mukavemetini artırmak için biyopolimerleri ek maddelerle birleştirmek nadirdir. Bu çalışma, Guar Gum ve Xanthan Gum biyopolimerlerinin kalsiyum klorür (CaCl₂) ile birlikte kullanılmasının siltli zeminin mukavemet parametreleri üzerindeki etkilerini araştırmaktadır. Biyopolimerlerin zemin matrisi arasında jel benzeri yapılar oluşturarak mukavemeti artırdığı bilinmektedir. Aynı zamanda kalsiyum klorür, biyopolimerlerin karboksil gruplarıyla etkileşime girerek zemin mukavemetini daha da artıran çapraz bağlar oluşturur. Bu çalışmada, biyopolimerler ve kalsiyum klorür siltli zeminle birleştirilerek ve 7,28,56 ve 90 günlük kürlemeye tabi tutulmuştur. Kürlenen numunelerin serbest basınç ve kayma mukavemetleri, referans numune ile karşılaştırılmıştır. İçsel sürtünme açısı ve kohezyondaki değişiklikler de farklı biyopolimer oranlarına göre analiz edilmiştir. Sonuçlar, kalsiyum klorürün biyopolimerlerin çapraz bağlama etkisini artırmasıyla uzun süreli kürlenmiş numunelerin mukavemetinde önemli iyileştirmeler olduğunu göstermiştir. Bu bulgular, biyopolimerlerin kalsiyum klorürle birlikte çevre dostu zemin stabilizasyon projelerinde etkili olabileceğini ortaya koymaktadır.

Anahtar Kelimeler

• Biyopolimer
• Zemin iyileştirme
• Xanthan gum
• Guar gum
• Çapraz bağlanma

Kaynakça

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