Interphase Effect on the Macro Nonlinear Mechanical Behavior of Cement-Based Solidified Sand Mixture.

Area of Science:

• Geotechnical Engineering
• Materials Science
• Computational Mechanics

Background:

• Cement-based solidified sand mixture (CBSSM) is crucial for soft soil foundation reinforcement, offering cost reduction and pollution mitigation.
• CBSSM is a multiphase composite comprising soil, cement, sand, and water.
• The interphase between sand aggregates and the cement-based solidified soil (CBSS) phase is often porous and weak, yet its mechanical impact is understudied.

Purpose of the Study:

• To investigate the influence of the interphase on the macro nonlinear mechanical behavior of CBSSM.
• To clarify the mechanical relationship between the interphase and the overall CBSSM performance.
• To provide insights for optimizing CBSSM in engineering applications.

Main Methods:

• Finite element numerical simulation using Abaqus.
• Unconfined compression experiments to obtain nonlinear stress-strain curves.
• Monte Carlo method and Python code for generating realistic CBSSM geometric models with random aggregate distribution.
• Bilinear Cohesive Model (CM) to simulate interphase damage behaviors.

Main Results:

• A significant interphase effect on CBSSM mechanical behavior was identified.
• Increased interphase strength and stiffness positively correlate with macro load capacity and service life.
• A higher number of interphases was found to negatively impact CBSSM durability.

Conclusions:

• The interphase plays a critical role in the macroscopic mechanical properties of CBSSM.
• Optimizing interphase characteristics is essential for enhancing the performance and longevity of CBSSM in geotechnical applications.
• Findings offer valuable guidance for practical engineering design and construction involving CBSSM.