Generally speaking, solid sodium silicate is primarily used in concrete as an accelerator, waterproofing agent, and reinforcement. Its core advantage lies in its rapid reaction with cement hydration products, significantly improving the setting time and density of concrete. The following are its key performance advantages:
1. Excellent Rapid Setting: This is the most classic application of sodium silicate.
• Mechanism of Action: When sodium silicate solution is added to concrete, it rapidly reacts with calcium hydroxide (Ca(OH)₂) produced by cement hydration to form a calcium silicate (CaSiO₃) gel. This gel encapsulates cement particles, forming a dense network structure, significantly accelerating the setting and hardening of concrete.
• Performance Advantages:
◦ Rapid Initial and Final Setting: Concrete sets within minutes to tens of minutes, far exceeding the hours required for conventional concrete.
It is suitable for emergency projects such as tunnel support, mine wall leak plugging, and pool repair, where rapid water stabilization or early strength development is required.
◦ Used in shotcrete: It is an essential accelerator in both dry and wet shotcrete processes, ensuring rapid setting and preventing detachment of concrete after application.
2. Significant waterproofing and impermeability properties • Mechanism of action: The calcium silicate gel and subsequent precipitate produced by the reaction effectively block capillary channels and micro-cracks within the concrete, significantly reducing its porosity and making the concrete denser.
• Performance advantages:
◦ Improved waterproofing: This effectively resists water penetration and is suitable for structures requiring waterproofing, such as basements, dams, water tanks, and swimming pools.
◦ Enhanced freeze-thaw resistance: By making it less susceptible to water ingress, freeze-thaw damage to concrete in cold regions can be reduced (freeze-thaw damage requires water).
3. Improved durability and corrosion resistance
• Mechanism of action: The sodium silicate reaction increases the alkalinity of the concrete and forms a protective layer, providing a certain degree of resistance to corrosion from acids, salts, and other chemicals.
• Performance Advantages:
◦ Acid Corrosion Resistance: While not completely resistant to strong acids, it offers good resistance to attack by weak acids and acidic gases (such as CO₂), making it suitable for environments such as industrial flooring and chemical workshops.
◦ Carbonation Resistance: High alkalinity helps protect rebar from rust (stabilizing the passive film) and slowing the carbonation process in concrete.
4. Increased Surface Strength and Wear Resistance
• Mechanism of Action: The resulting calcium silicate gel is extremely hard, filling pores and making the concrete surface harder and denser.
• Performance Advantages:
◦ Suitable for Flooring: Commonly used in industrial flooring applications requiring high strength and wear resistance, such as warehouses, workshops, and parking lots. ◦ Sanding Treatment: It can be used to address dusting and sanding issues on the concrete surface, providing sealing and reinforcement.
5. Cost-Effectiveness • Solid sodium silicate is widely available as a raw material and has a mature production process. It is a relatively inexpensive chemical additive that can effectively reduce the overall cost of specific projects (such as water-stopping and leak-proofing).
Post time: Sep-20-2025