Microsilica Gel

Microsilica Gel

MGP410

Superplasticizing and Waterproofing Paste Additive
Permeability Reduction and Water-Reducing Agent

Description of Microsilica Gel

Microsilica Gel is an advanced modified additive based on polycarboxylate ether, composed of microsilica powder, high-range water reducer, water-repellent agents, and polypropylene fibers. This additive is used for producing high-performance, impermeable, and durable concrete.

As a super pozzolan, Microsilica Gel significantly enhances the strength, durability, and overall properties of concrete. It increases concrete density, improves compressive, flexural, and tensile strength, and enhances workability without requiring an additional superplasticizer.

Mechanism of Action of Microsilica Gel

The silica fume in Microsilica Gel is a highly reactive pozzolanic material that acts as a supplementary cementitious component. Upon mixing with water and calcium hydroxide, it undergoes a chemical reaction, forming calcium silicate hydrate (C-S-H) gel, which significantly contributes to the strength development and durability of concrete.

Additionally, the polycarboxylate ether in the formulation acts as a high-performance superplasticizer. It forms a thin membrane around cement particles, preventing particle agglomeration through steric hindrance and generating electrostatic repulsion, leading to improved workability and fluidity.

Moreover, polypropylene fibers further enhance the mechanical properties and abrasion resistance of concrete.

Properties and Benefits of Microsilica Gel

• Creates a smooth, exposed concrete surface
• Reduces cement content by 15% to 20%
• Prevents thermal stress-induced cracks
• Eliminates bleeding and segregation
• Enhances compressive, tensile, and flexural strength
• Increases abrasion and electrical resistance
• Improves durability against freeze-thaw cycles
• Enhances workability without requiring additional superplasticizers
• Facilitates pumping and reduces equipment wear
• Significantly minimizes surface cracking
• Prevents corrosion of rebar and steel reinforcements
• Reduces water-to-cement ratio and improves rheological properties
• Minimizes water permeability and resistance against chloride and sulfate attacks
• Produces highly cohesive and homogeneous concrete

Applications of Microsilica Gel

• Ideal for high-strength and high-performance concrete
• Suitable for mass concrete placements
• Effective for concrete exposed to freeze-thaw cycles
• Recommended for waterproof and impermeable concrete
• Used in marine structures, bridges, decks, reservoirs, and dams
• Applicable for blast-resistant concrete
• Suitable for chemical and corrosion-prone environments
• Compatible with tunnels, water channels, treatment plants, and storage tanks
• Used in industrial hard-wearing concrete floors
• Applicable for both reinforced and non-reinforced concrete

Physical and Chemical Properties of Microsilica Gel

Property	Specification
Form	Thick slurry or gel
Color	Dark gray
Specific Gravity	1.35 g/cm³
Standards	BS 1881-122, BS EN 12390-8
Chloride Content	None
pH Value	~9

 

Dosage of Microsilica Gel

The optimal dosage of Microsilica Gel depends on laboratory evaluations, considering factors such as material composition, cement type, and environmental conditions.

Typically, the recommended dosage ranges between 5% to 7% of the cement weight. To achieve high compressive strength and durable concrete, 10% to 15% of the mixing water should be reduced before adding the gel.

Instructions for Use

Microsilica Gel can be incorporated into the concrete mix using two methods:

1. Pre-mixing Method:
   • Mix Microsilica Gel with all or part of the mixing water before adding it to the dry components.
2. Post-mixing Method:
   • Add Microsilica Gel to the concrete mix after all components have been incorporated.

Important Notes

• A minimum mixing time of 1 minute per cubic meter of concrete is required.
• For extended delays between mixing and placement, it is recommended to add Microsilica Gel in two stages:
  • The first portion at the batching plant.
  • The second portion 5 minutes before placement, mixing for an additional 2 to 4 minutes.

Safety Guidelines

• Microsilica Gel is non-toxic and environmentally friendly.
• If swallowed, seek medical attention immediately.
• In case of contact with skin or eyes, rinse immediately with plenty of fresh water.
• Use protective gloves, safety goggles, and a mask when handling any chemical additives.

Storage Conditions

• Shelf Life: 1 year in original, sealed packaging.
• Store in a dry, cool place away from direct sunlight, extreme heat, and frost.
• Optimal storage temperature: +10°C to +30°C.

Packaging

• 25 kg pail