Flexural Response of Functionally Graded Rubberized Concrete Beams

Area of Science:

• Materials Science
• Civil Engineering
• Sustainable Construction

Background:

• Waste tires present a significant recycling challenge.
• Incorporating recycled rubber in concrete offers sustainability benefits but can negatively impact mechanical properties.
• Functionally graded (FG) materials offer a potential solution to mitigate property degradation.

Purpose of the Study:

• To investigate the flexural behavior of functionally graded (FG) concrete beams incorporating recycled rubber and steel fibers.
• To evaluate the effectiveness of FG beams in overcoming the limitations of rubberized concrete in structural applications.
• To compare the performance of FG beams with plain concrete and conventional rubberized concrete beams.

Main Methods:

• Five beams were tested under a four-point bending configuration.
• Beams included plain concrete, rubberized concrete (RuC), steel-fiber reinforced rubberized concrete (SFRRuC), and two-layered FG beams (plain concrete top layer, RuC or SFRRuC bottom layer).
• Moment-curvature relationships were predicted and compared with experimental data.

Main Results:

• FG beams with steel-fiber reinforced rubberized concrete (SFRRuC) and plain concrete layers demonstrated enhanced flexural strength (9.9%), displacement ductility ratio (12.9%), and toughness (24.4%) compared to plain concrete beams.
• The predicted moment-curvature relationships closely matched the experimentally measured ones.
• Steel fiber reinforcement significantly improved the performance of rubberized concrete components.

Conclusions:

• Functionally graded beams offer a promising approach to utilize recycled rubber and steel fibers in concrete construction.
• FG beams incorporating SFRRuC can overcome the reduced flexural performance typically associated with rubberized concrete.
• This study validates the potential of FG beams for sustainable and high-performance construction materials.