Novel Fractional Approach to Concrete Creep Modeling for Bridge Engineering Applications

Area of Science:

• Civil Engineering
• Materials Science
• Structural Engineering

Background:

• Concrete creep is a critical factor in bridge structure longevity.
• Accurate modeling of concrete creep is essential for modern construction techniques like balanced cantilever and incremental launching.
• Existing design codes like Eurocode 2 may not fully capture creep behavior for all concrete mixes.

Purpose of the Study:

• To investigate the influence of concrete mix composition, specifically blast furnace slag content and air-entrainment, on concrete creep.
• To calibrate and validate advanced fractal rheological models (Kelvin-Voigt and Huet-Sayegh) for improved creep prediction.
• To compare the accuracy of proposed models with existing standards like Eurocode 2.

Main Methods:

• Laboratory testing of nine concrete mixes with varying blast furnace slag content (0%, 25%, 75%) and air-entrainment.
• Calibration of fractal rheological models by replacing the viscous element with a fractal element.
• Experimental data validation of the calibrated models for creep prediction.

Main Results:

• The fractal rheological models demonstrated high agreement with experimental creep data.
• The proposed models significantly improved the accuracy of creep prediction compared to traditional methods.
• Discrepancies of up to 64% were observed when comparing model predictions with Eurocode 2, particularly for slag-free concretes.

Conclusions:

• Mineral additives, such as blast furnace slag, play a crucial role in reducing concrete creep strains.
• Individual concrete mix characteristics must be considered in structural design calculations for accurate long-term behavior analysis.
• The proposed advanced modeling approach offers enhanced precision for analyzing long-term structural behavior, contributing to safer and more durable concrete infrastructure.