Elastomeric bridge expansion joints, commonly known as rubber Bridge Expansion Joint or mat expansion joints, provide a durable and cost-effective sealing solution for bridges with low to moderate movement ranges. Their design leverages the inherent properties of elastomers to ensure smooth traffic flow and long-term performance.
Product Classification: Pre-fabricated, reinforced elastomeric bearing-seal assembly for continuous bridge deck surfaces.
Core Operating Principle: Accommodates structural movements (thermal expansion/contraction, creep, shrinkage) through controlled, multi-axial deformation of the elastomeric matrix. The joint functions via:
Compression & Elongation: To absorb translational movement along the bridge axis.
Shear Deformation: Within the internal webbing or across the entire element to accommodate multi-directional shifts without mechanical failure.
Moment Resistance: The reinforced structure provides rotational stability at the deck end.
Material: rubber, steel plate and angle iron.
Table 1: Specification of Elastomeric expansion joint | ||||
Model | Movement | Module length | Module depth | Weight |
30 | ± 15 | 2000 | 33 | 18 |
50 | ± 25 | 2000 | 43 | 25 |
80 | ± 40 | 2000 | 46 | 34 |
100 | ± 50 | 2000 | 54 | 45 |
160 | ± 80 | 2000 | 84 | 88 |
200 | ± 100 | 2000 | 71 | 135 |
330 | ± 165 | 1000 | 100 | 280 |
Accessories:
· Kidney-shaped cap.
· Curved screw bolt.
· Ring.
Elastomeric Element:
Base Compound: Prime-grade Neoprene (CR) or Ethylene Propylene Diene Monomer (EPDM).
Key Properties:
Hardness (Durometer): 60-70 Shore A, optimized for load-bearing and flexibility.
Tensile Strength: ≥ 15 MPa.
Elongation at Break: ≥ 350%.
Weathering Resistance: Formulated with anti-ozonants and carbon black for superior UV and ozone resistance (Tested per ASTM D1149).
Reinforcement System:
Internal Reinforcement: Multiple layers of steel or high-tensile fabric laminates, fully vulcanized-bonded to the elastomer.
Function: Provides structural capacity to distribute wheel loads and prevent buckling under compression, while allowing for controlled shear deformation.
Anchorage System:
Components: Pre-drilled hot-dip galvanized steel (≥ 80µm) angle irons or L-shaped profiles.
Installation Interface: Anchor bolts are set in a high-strength, non-shrink epoxy grout (e.g., ASTM C881 Grade 3) to ensure precise alignment and load transfer to the concrete substrate.
Movement Capacity: Certified for total movement ranges from 0 mm to 60 mm.
Load Rating: Engineered to support AASHTO HL-93 and Eurocode LM1 traffic loading without significant deflection.
Waterproofing Integrity: The monolithic elastomeric body, combined with epoxy-sealed bolt holes and junctions, creates a continuous, high-pressure watertight seal, preventing ingress and protecting substructures.
Durability & Maintenance:
Abrasion Resistance: High resistance to tire wear, validated by ASTM D5963 testing.
Corrosion Protection: All internal steel is hot-dip galvanized per ASTM A123.
Maintenance: Requires no periodic lubrication or mechanical adjustment, resulting in near-zero lifecycle maintenance.
Substrate Preparation: Requires a clean, sound concrete edge with a compressive strength of ≥ 30 MPa at time of installation.
Critical Installation Step: All anchor bolt cavities and interfacial gaps must be fully potted with a flowable, structural epoxy adhesion agent to achieve the specified waterproof performance and composite action with the deck.
Vertical Applications: Bridge ends (between deck and abutment), approach slabs.
Structural Types: Ideal for standard grade-separation flyovers, urban viaducts, and concrete frame structures where movement demands are moderate and noise damping is a priority.
Project Phase: Suitable for both new construction and rehabilitation projects as a direct replacement for failed asphalt plugs or simpler joint systems.
Explore our heavy-duty Aluminum Finger Expansion Joints for movements from 150mm to 1200mm. Offering superior corrosion resistance, lower lifecycle cost, and full compliance with AASHTO & Eurocode standards. The durable alternative to steel joints.
The Aluminum Finger Expansion Joint, also known as a comb joint, is a heavy-duty mechanical system engineered to accommodate the largest thermal expansions, contractions, and dynamic movements in bridge and structural applications. It is specifically designed for movement ranges from 150 mm to 1,200 mm.
The system operates on an intermeshing finger principle. It consists of a series of symmetrical or asymmetrical aluminum finger plates anchored on either side of the expansion gap. These robust "fingers" interlock with each other, bridging the gap. As the bridge structure moves, the fingers slide and/or lift over one another, safely absorbing multi-directional movements (longitudinal, transverse, and rotational) while maintaining a continuous deck surface for traffic.
Arbridge Series Elastomeric Expansion Joints are engineered to handle a wide range of movements, from moderate ±25 mm shifts to very large ±200 mm+ displacements. Integrating elastomeric cores with reinforced metallic elements and robust anchoring, they provide exceptional durability, watertightness options, and minimal maintenance over a long service life.
Finger expansion joints are engineered to accommodate structural movements ranging from 80 mm to 1,200 mm. These joints consist of steel finger plates, CR (chloroprene) rubber sheets, anchor bolts, and other essential components. A durable rubber sheet is mounted over the retractable steel assembly, while anchor bolts secure the entire structure in place.
The fingers are oriented in the direction of vehicle travel, which helps reduce noise and enhance driving comfort. Additionally, a built-in drainage channel directs rainwater into the bridge’s drainage system, preventing water accumulation and supporting long-term durability.
Also referred to as comb expansion joints, finger expansion joints feature symmetrical or asymmetrical comb-like (saw-tooth or sinusoidal) plates. These plates are anchored on one side of the deck joint gap and interlock to span the opening. Symmetrical finger joints, often called cantilever expansion joints, are typically used for smaller movement ranges. In contrast, asymmetrical designs—known as supported finger expansion joints—are better suited for larger expansion requirements.
Available in various tooth profiles to match specific application needs.
Modular Expansion Joints are engineered systems designed to accommodate large longitudinal movements in bridge structures, typically within a range of 80 mm to 1200 mm. The core mechanism consists of a series of parallel, movement-controlled center beams, supported at predetermined intervals by a substructure of cross beams or girders. This assembly is anchored between two edge beams, which are rigidly and watertightly connected to the bridge deck. The top surfaces of all beams are precision-set flush with the road surface to ensure a continuous running plane.
Explore our high-performance Strip Seal Expansion Joints for movement ranges from 0 to 80mm. Featuring a robust steel and EPDM/Neoprene design, they deliver superior watertight sealing, noise reduction, and durability for bridge and infrastructure projects.
The Strip Seal Expansion Joint is a premier solution for effectively sealing expansion gaps in bridges and structures with movement ranges from 0 mm to 80 mm. Its intelligent design combines high-strength steel with a durable elastomeric seal to create a reliable, long-lasting barrier against the elements and dynamic traffic loads.
Westcoast New Area, Qingdao City ,Shandong Province ,China
