Stress-strain behavior of cementitious materials with different sizes

Area of Science:

• Civil Engineering
• Materials Science
• Structural Engineering

Background:

• The flexural properties of cementitious materials are influenced by specimen size.
• Existing size effect laws provide a basis for understanding this phenomenon.
• The stress-strain behavior of cement mortar and concrete requires further refinement to account for size variations.

Purpose of the Study:

• To investigate the size dependence of flexural properties in cement mortar and concrete beams.
• To evaluate the applicability of established size effect laws.
• To propose a modified equation for stress-strain curves that incorporates size-dependent correction factors.

Main Methods:

• Experimental testing of cement mortar and concrete beams of varying sizes.
• Analysis of flexural strength using Bazant's size effect law and Kim and Eo's modified law.
• Development and empirical validation of a modified Li's equation with size-dependent correction factors.

Main Results:

• Both cement mortar and concrete beams exhibit a significant size effect on flexural strength.
• Cement mortar demonstrates a more pronounced size effect compared to concrete.
• The modified Li's equation accurately predicts the stress-strain behavior across different specimen sizes.

Conclusions:

• The size effect is a critical factor in the flexural performance of cementitious materials.
• The proposed modified equation offers improved accuracy in describing size-dependent stress-strain relationships.
• Findings provide valuable insights for structural design and material characterization.