Bridge Reinforcement Professional High-Strength Self-Compacting Mortar and Self-Compacting Concrete Technology

Bridge-specific CBGM High-Strength Self-Compacting Mortar
CBGM bridge-specific high-strength self-compacting mortar is a self-leveling, self-compacting, high-strength, and non-shrinkage mortar formulated with cement as the primary binder, high-strength materials (quartz sand or emery) as aggregates, and supplemented with high fluidity, micro-expansion, and anti-segregation agents.
I. Product Features                                                               
1. Self-Leveling Property
Flowability ≥300mm, enabling uniform diffusion and free flow after pouring.
2. Self-Compacting Property
Excellent fluidity, no bleeding or segregation, no vibration required, capable of filling vertical slab joints under its own weight.
3. Early High Strength
High early strength: 1d strength ≥20 MPa, 3d strength ≥40 MPa, 28d strength ≥70 MPa. Meets strength requirements for both old slab joints (C40) and new slab joints (C60).
Shortens construction period: For old slab joints, pavement layer construction can proceed after 24h; for new slab joints, after 48h.
4. Micro-Expansion
Expansion agents in the mortar prevent sedimentation shrinkage and moisture loss shrinkage, avoiding hollowing after pouring and reducing effective load-bearing surface.
5. Durability
Inorganic mixture, resistant to corrosion and aging.
Domestic studies show: No significant strength change after 2 million fatigue tests and 50 freeze-thaw cycle tests.
II. Performance Indicators                                                                  

Note: 1. All performance indicators in the table should be tested according to the maximum water content required by the product;
2. For CBGM bridge-specific high-strength self-compacting mortar used in winter construction, the 30min retention value and the difference between 24h and 3h expansion values are not required.
III. Construction Technology                                                           
1. Scope of Application
① Primary Application: Suitable for repair and reinforcement of bridge slab joints.
② Other Applications: After adjusting the mix ratio, it can be used for grouting prestressed ducts, emergency repair of expansion joint concrete works, reinforcement of concrete members with increased cross-sections, and emergency repair of concrete pavements.
2. Construction Technology
(1) Process Flow
① Cross-Section Enlargement Construction for Bridge Structures

② Repair of Bridge Slab Joints
A. Traditional Grouting Method
Involves removing the bridge deck pavement layer, grouting the slab joints, and then repaving the deck pavement layer. This method is suitable for repairing and reinforcing bridge slab joints where the deck is severely damaged, traffic maintenance pressure is low, and road sections can be occupied for a longer period. The construction process is as follows:

B. Top Drilling Minimally Invasive Grouting Method
Involves drilling holes along the top of the slab joints without removing the deck pavement layer, performing pressure grouting, and then sealing the holes. This method is suitable for repairing and reinforcing bridge slab joints where the deck is undamaged or slightly damaged, traffic maintenance pressure is high, and road sections cannot be occupied for long periods. The construction process is as follows:

C. Bottom Shock Absorption Minimally Invasive Grouting Method
Involves drilling holes along the bottom of the slab joints without removing the deck pavement layer, installing reinforcement bars, setting transverse prestress between slabs to resist vibrations from traffic loads, performing pressure grouting, and then sealing the holes. This method is suitable for repairing and reinforcing bridge slab joints where the deck is undamaged or slightly damaged, traffic maintenance pressure is high, and traffic cannot be interrupted. The construction process is as follows:
(2) Construction Steps
① Cross-Section Enlargement Construction for Bridge Structures
A. Surface Preparation: Roughen the structural surface with a steel chisel, thoroughly remove loose material, and clean dust with an air compressor.
B. Surface Wetting: Fully wet the surface with water 2~3 hours before pouring and remove standing water; during winter construction, wet the surface with warm water not exceeding 65°C and remove standing water before pouring.
C. Interface Treatment: Apply a uniform layer of polymer-based interface agent on the surface.
D. Formwork Installation: Erect formwork according to the design dimensions for cross-section enlargement and take measures to prevent grout leakage.
E. Mixing: Based on the on-site pouring volume and speed, manually add the repair material into a forced-action mortar mixer. After dry mixing for 10s, add water in two stages according to the product's specified water content: first add 2/3 of the water and mix for 30s; then add the remaining 1/3 water and mix for 150s. After mixing, let the repair material sit for 2~3min until bubbles disappear before pouring. During winter construction, use warm water not exceeding 65°C for mixing, and the pouring temperature should be above 10°C.
F. Pouring: Pour slowly and evenly using a grouting machine or pouring container to ensure density and avoid hollowing. Level the top surface after pouring. The time from mixing start to pouring end should not exceed 30min. Repair material that exceeds this time or does not meet flowability requirements should not be used.
G. Demolding and Curing: Under normal temperatures, demolding can be done after 24h. Then cover the enlarged section with plastic strips, and completely cover the plastic strips with straw mats to maintain moisture. Curing can end after 3~4d, or based on structural strength requirements and test results of reserved specimens. During winter, use insulation measures and extend the curing period appropriately.