What Is Non-Shrink Grout and Why Do You Need It?

Non-shrink grout is a cement-based material with specific performance properties, widely used in construction and civil engineering. During the hardening process, it undergoes micro-expansion to compensate for the shrinkage that occurs during cement curing, ensuring structural stability and durability. Below we introduce the key properties of non-shrink grout and its importance in engineering applications.

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Properties

1. Shrinkage Compensation

Shrinkage compensation means the grout micro-expands during hardening to offset the shrinkage effect of cement curing. This expansion occurs primarily during the plastic and hardening phases, ensuring the material does not develop shrinkage cracks after setting. This property is critical for maintaining structural integrity and stability, particularly in high-stress and heavy-load applications. Additives in non-shrink grout generate expansion during the plastic and hardening process, effectively compensating for volume reduction caused by moisture evaporation and cement hydration.

2. Easy to Mix and Apply

Non-shrink grout is typically a single-component product that only requires adding the correct amount of water. This straightforward process makes construction more convenient while ensuring uniform mixing and consistent quality.

3. Excellent Flowability

This type of grout material has outstanding flowability, easily filling voids, cavities, and gaps of various shapes and sizes. Good flowability ensures even distribution, preventing voids and weak points.

4. Rapid Strength Development

Non-shrink grout develops high strength early in the hardening process, meaning structures can bear loads sooner, shortening construction timelines and improving efficiency.

5. High Ultimate Strength

After full curing, non-shrink grout achieves very high ultimate strength, meeting the demands of heavy-duty and high-load applications. This high-strength characteristic makes it suitable for structures that must withstand significant pressure and impact.

6. Impact and Vibration Resistance

The material offers excellent impact and vibration resistance, suitable for environments with dynamic loads and mechanical vibration, ensuring structural durability and stability.

7. Non-Corrosive

Non-shrink grout contains no chlorides or other corrosive substances, eliminating the risk of corroding reinforcing steel and bolts, thereby extending the project's lifespan and ensuring structural safety.

Applications

Non-shrink grout is widely used in the following areas:

1. Machinery Foundations

In machinery base construction, non-shrink grout provides high strength and stability, ensuring safe and stable equipment operation.

2. Precast Building Columns

In precast column installation, non-shrink grout ensures stable and secure joints, preventing structural issues caused by shrinkage.

3. Concrete Anchoring

The high strength and shrinkage compensation properties make non-shrink grout ideal for anchoring bolts, reinforcing bars, and other fixtures.

4. Bridge Bearings

Bridge bearings must withstand dynamic loads and environmental exposure. The impact and vibration resistance of non-shrink grout makes it an ideal material choice.

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What Does 'Grout' Mean?

In Hong Kong's construction industry, Non-Shrink Grout is commonly known as 'five-star cement'. Grouting refers to the process of injecting flowable grout material into gaps, holes, or spaces between substrates and equipment, which then hardens to form a solid fill.

Limitations and Precautions

While non-shrink grout offers excellent performance, note these limitations:

• Temperature sensitive - High temperatures accelerate hardening and shorten working time; low temperatures slow strength development. Application is generally recommended between 5 and 35 degrees C.
• Accurate water content required - Too much water reduces strength and expansion; too little water results in poor flowability, making it difficult to fill narrow spaces.
• Thickness limits - Maximum single-pour thickness varies by product (typically 10-100mm per layer); excessive thickness may cause heat buildup and cracking.
• Not suitable for dynamic joints - Non-shrink grout sets rigid and is not suitable for joints requiring ongoing movement. Use flexible joint sealant for such applications.
• Curing requirements - Keep the surface moist after application to prevent rapid moisture loss and surface cracking.

Non-Shrink Grout Brand Comparison

Here are the main non-shrink grout products we supply:

Weber's Five Star Grout is a well-known grouting product series widely used in Hong Kong's construction industry. Optimix NS612 and Ronacrete Ronagrout GP have both obtained PCCS-RM S certification from the Hong Kong Concrete Institute.

How to Choose the Right Grout Product

• General grouting and anchoring - Standard products like Weber Non Shrink Grout GP or Conbextra GP are sufficient.
• Certified projects - Choose PCCS-RM certified products (such as NS612 or Ronagrout GP), suitable for government projects or Housing Authority works.
• Precision equipment bases - Select high-precision grouting products (such as Five Star Grout SP) to ensure complete baseplate support.
• Concrete repair - Some grouting products (such as Ronagrout GP and NS612) also serve as repair materials for filling honeycombing and voids.

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