Installation and Construction Plan for Finger Expansion Joints

Preparations

1.Equipment:

• Road surface cutting machine

• Steel bar straightening machine

• Steel bar cutting machine

• Steel bar bending machine

• Jack

• Air compressor

• Vibrator

• AC welding machine

• Oxygen-acetylene welding and cutting equipment

Inspection Equipment:

• 3 m road surface flatness (straight ruler)

• Road surface flatness detector

2. We have completed the asphalt concrete surface layer. We adjusted the joints’ length and width. They did this to match the design and installation temperature.

3. All finger expansion joints, plus any tools or materials, must be on-site before work starts.

Start Construction

(1) Marking and Cutting

Installation of Finger Expansion Joints

After the crew compacts and cools the top layer of asphalt concrete, they should mark where to place the Finger Expansion Joints. This should follow the design drawings. Mark the edge lines for the installation slot. Use the design dimensions and the reserved slot width. Then, use an asphalt concrete cutting machine to cut along these marked lines. Quality control points:

a. If the edge of the joint area on the asphalt is uneven, extend the marking to the flat part. Then, cut the marking.

b.When marking, follow these rules:

• If the existing embedded slot is smaller than the design size, mark it to the design size.

• If the existing embedded slot is larger, mark it to the size of the existing slot.

Make sure the transition sections on both sides of the device are the same width after installation.

c. When cutting, strictly follow the marked lines and ensure that the slot is straight.

(2) Digging and Cleaning the Joint Area

1. Dig and clean the asphalt concrete layer and debris in the slot area based on the cut joint width.

2. Roughen the bottom of the joint area. Clean out any debris. This helps the future concrete bond tightly to the beam.

3. Place the debris at least 1 meter from the joint edge. Put a plastic sheet underneath. If conditions permit, remove it from the construction site on time.

4. When digging, be careful. Don’t damage the bridge’s main structure. Also, avoid harming the asphalt road outside the joint area. This includes breaking corners or lifting the surface.

(3) Check if the width of the beam-end structural joint meets the gap requirements under the temperature conditions.

(4) Position and weld anchor bolt groups. Use the bolt hole template for positioning. The bolt rod position error should not exceed ±1 mm. Firmly connect and weld the reinforcing bars to the anchor bolts using a steel mesh.

(5) Install the waterstop components.

Tie the transition bottom plate’s reinforcing bars. Then, set up the formwork. Finally, pour C40 steel fiber concrete. Check the slot before pouring. Make sure it is clean and look for any leaks. Then, pour the concrete. Control the top surface elevation and flatness of the concrete pavement. It should match the longitudinal and transverse slopes of the bridge deck. Also, the height difference with the top surface of the Finger Expansion Joints must be between -2.0 mm and 0.0 mm. We should control the flatness within 0.1 mm. Use a straight ruler to smooth the surface at least twice. This helps ensure flatness before the concrete sets.

Install the stainless steel plate along with the main and auxiliary tooth plates. Then, tighten them using nuts. Apply anti-loosening glue to the threads. Also, spot-weld the bolts and nuts lightly to stop them from loosening. The height difference between adjacent tooth plates should be ≤ 3 mm.

(7) Water curing of the concrete.

(8) Pour waterproof grease into the gap of the finger expansion joints.