Coating modification of glass bubble is an effective method to enhance the workability and mechanical properties of lightweight concrete. The surface treatment improves adhesion, dispersion, and interface bonding between the glass bubble and the cement matrix, reducing potential weaknesses while maintaining weight reduction benefits.
- Silane Coupling Agents
- Polymer Coatings (Epoxy, Polyurethane, Polyacrylate)
- Nano-Silica or Pozzolanic Coatings
- Calcium Carbonate or Cementitious Coatings
- Graphene Oxide or Carbon-Based Coatings
Common Coating Modification Approaches
Enhances compatibility with cement and polymers.
Improves dispersion and bonding, reducing microsphere breakage.
Common silanes: Aminosilane, Epoxysilane, Vinylsilane.
Provides a protective layer to prevent crushing during mixing.
Enhances impact resistance and flexural strength.
Improves workability by reducing water absorption.
Promotes hydration reaction and strengthens the interfacial transition zone (ITZ).
Increases compressive strength and durability.
Enhances compatibility with the cement paste.
Reduces microcracking by acting as a micro-filler.
Improves tensile and flexural strength.
Enhances thermal and electrical conductivity, useful for smart concrete applications.
Impact on Lightweight Concrete Properties
- Workability:
- Mechanical Properties:
- Durability:
Modified glass bubbles prevent excessive water absorption, leading to smoother mixing.
Improved dispersion minimizes clustering and maintains uniformity.
Enhanced bonding with the matrix improves compressive, flexural, and impact strength.
Reduces microcracking and enhances fracture toughness.
Surface coatings can reduce permeability, improving water and chemical resistance.
Prevents alkali-silica reaction (ASR) issues.