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Physical Characterization of Cementitious Materials on Casting and Placing Process
1Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea. yimhongjae@gmail.com.
Materials (Basel, Switzerland)
|August 10, 2017
Summary
Cement particle coagulation, crucial for fresh cement-based materials, influences rheology and hydration. This study categorizes microstructural buildup into permanent coagulation and strong/weak flocculation.
Area of Science:
- Materials Science
- Civil Engineering
- Colloid Science
Background:
- Coagulation of cement particles is a fundamental process in cement-based materials during solidification.
- This phenomenon impacts rheological properties (shear thinning, thixotropy) and hydration kinetics.
- Understanding coagulation is key to controlling fresh concrete properties.
Purpose of the Study:
- To quantify the mechanical properties and coagulation behavior of cement particles.
- To investigate the influence of mix proportions on cement paste coagulation.
- To establish a classification system for microstructural buildup in fresh cement pastes.
Main Methods:
- Utilized a laser backscattering instrument to measure two types of coagulation (reversible flocculation and irreversible coagulation).
- Analyzed variations in volume fraction and size distribution of coagulated particles.
- Correlated mix proportions with observed coagulation characteristics.
Main Results:
- Experimental setups successfully differentiated between reversible flocculation and irreversible coagulation.
- Quantified particle volume fraction and size distribution, revealing distinct variations.
- Identified three distinct categories of microstructural buildup: permanent coagulation, strong flocculation, and weak flocculation.
Conclusions:
- The study provides a quantitative method for assessing cement particle coagulation.
- Mix proportions significantly influence the type and extent of coagulation.
- A three-category classification (permanent coagulation, strong/weak flocculation) effectively describes fresh cement paste microstructure.
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