Mechanical Behavior and Predictive Modeling of Cementitious Composites Incorporating Recycled HDPE

Area of Science:

• Materials Science
• Civil Engineering
• Environmental Science

Background:

• Plastic waste, particularly High-Density Polyethylene (HDPE), presents a significant environmental challenge.
• Recycling plastic waste into construction materials offers a sustainable solution for waste management.
• Incorporating recycled materials into concrete requires understanding their impact on mechanical properties.

Purpose of the Study:

• To investigate the feasibility of using HDPE granules as fine aggregate replacements in concrete.
• To quantify the effects of varying HDPE substitution rates on concrete's physical and mechanical properties.
• To develop and validate predictive models for assessing HDPE's influence on cementitious composites.

Main Methods:

• High-Density Polyethylene (HDPE) granules were used to replace fine aggregate in concrete at 10%, 20%, and 30% by volume.
• Standard tests were conducted to evaluate slump, density, compressive strength, tensile strength, flexural strength, modulus of elasticity, and strain.
• A comprehensive database combining experimental results with existing literature data was created for model development.

Main Results:

• Increasing HDPE substitution rates led to decreased compressive strength (12-34%), tensile strength (7-23%), flexural strength (6-21%), and modulus of elasticity (15-34%).
• Axial and lateral strain values increased by 4-44%, while density (3-9%) and slump (4-19%) decreased with higher HDPE content.
• Developed exponential equations accurately predicted mechanical properties, outperforming existing models in statistical evaluations.

Conclusions:

• HDPE can be utilized as a fine aggregate replacement in concrete, contributing to plastic waste recycling.
• While HDPE incorporation negatively impacts concrete's mechanical strength, its effect on strain capacity is positive.
• The proposed predictive models offer a reliable tool for assessing the mechanical performance of HDPE-modified cementitious composites.