Grout

Introduction to Grout

Grout is a product specifically designed for post-tensioned prestressed duct (hole) grouting construction. It is formulated from a variety of high-quality cement-based materials and high-performance additives, offering excellent fluidity, stable slurry, good filling capacity, adjustable setting time, non-shrinkage, micro-expansion, high strength, and contains no substances harmful to reinforcement.

Application Purpose

1. Protect prestressed tendons from corrosion and ensure the safety of prestressed structures.

2. Ensure the bonding force between prestressed tendons and concrete, enabling effective transfer of prestress between them, allowing prestressed tendons and concrete to work together.

3. Eliminate fatigue damage to anchors caused by stress changes in prestressed concrete structures under repeated loads, extend the service life of anchors, and improve structural reliability.

Application Fields

1. Grouting of ducts in various post-tensioned prestressed railway and highway bridges.

2. Grouting of ducts in large prestressed structures.

3. Leak-stopping grouting at various concrete structure joints.

4. Curtain grouting, anchor grouting, void filling, or repair, etc.

Technical Indicators

JTG/T3650-2020 "Technical Specifications for Highway Bridge Construction"

Construction Application

Construction Key Points

1. Water-to-material ratio is 0.26~0.28, adjustable based on the grouting location.

2. First, add 80%-90% of the actual mixing water into the mixer, start the mixer, and uniformly add all the grout material while stirring. After all the powder is added, quickly stir for 3 minutes, then add the remaining 10%-20% of mixing water and continue stirring for 2 minutes.

3. The duration from mixing the grout to injecting it into the duct depends on the temperature, generally within 30 minutes to 1 hour.

4. The grout should be continuously stirred before use and during injection to maintain uniformity and fluidity of the slurry.

5. Use a piston pressure pump or vacuum pump for grouting, with pressure required to be greater than 0.7MPa.

6. The slurry temperature should be maintained between 5°C and 30°C during grouting; otherwise, measures should be taken to meet the conditions.

Precautions

1. The mixer speed should not be less than 1000r/min.

2. Do not add water to increase the fluidity of cement slurry that has reduced fluidity due to delayed use.

3. During construction, in high-temperature conditions, choose cooler times such as nighttime construction; in low-temperature conditions, follow winter construction standards.

Packaging and Storage

1. Packed in laminated bags, net weight 40 kg/bag, shelf life of 6 months. Use beyond the shelf life should be verified by testing before use.

2. Avoid direct sunlight, prevent moisture and packaging damage. Store on pallets off the ground in a dry, ventilated indoor area.