Cost-Effective High-Performance Concrete: Experimental Analysis on Shrinkage.

Area of Science:

• Materials Science
• Civil Engineering
• Concrete Technology

Background:

• Shrinkage is a critical factor affecting the durability and performance of concrete structures.
• Understanding shrinkage behavior in Self-Compacting High-Performance Concrete (SCC HPC) is essential for its effective application.

Purpose of the Study:

• To experimentally determine the shrinkage process in SCC HPC under dry air and autogenous conditions.
• To compare shrinkage curves obtained using different measurement devices and specimen sizes.
• To investigate the influence of the initial measurement time (t0) on shrinkage values.

Main Methods:

• Utilized special molds (100 mm × 60 mm × 1000 mm and 50 mm × 50 mm × 300 mm) with movable heads for shrinkage measurement.
• Employed inductive sensors and embedded strain gauges for early-age shrinkage (48 h).
• Used embedded markers and mechanical strain gauges for long-term shrinkage monitoring after demolding.

Main Results:

• Both measurement equipment types yielded similar early-age shrinkage results, particularly under autogenous conditions.
• Early and long-term shrinkage measurements were influenced by sensor placement, especially in dry air conditions.
• The choice of initial measurement time (t0) fundamentally impacts final shrinkage values and size effect conclusions.

Conclusions:

• Measurement sensor position and the initial time of measurement significantly influence SCC HPC shrinkage assessment.
• Accurate determination of shrinkage requires careful consideration of measurement methodology and environmental conditions.
• The study highlights the importance of standardized procedures for reliable shrinkage evaluation in SCC HPC.