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SPECIFICATION FOR THE INSTALLATION OF THE THORMA-JOINT® ASPHALTIC PLUG EXPANSION JOINT SYSTEM

SCOPE

This work shall consist of supplying and installing a binder and aggregate system composed of specially blended polymer modified asphalt and specific aggregate placed in layers into a prepared expansion joint block-out. When properly installed, the THORMA-JOINT system by DSA will provide a flexible waterproof bridge joint, which will allow for a joint movement of 1” in expansion and 1” in compression.

MATERIAL SPECIFICATIONS

BJ Super™ Binder

The bridge joint binder shall be a polymer modified asphalt, as manufactured by Dynamic Surface Applications, and shall meet the following requirements as set forth is ASTM D6297-01 and when independently tested according to those standards.

Aggregate

The stone used shall primarily consist of Granite, Basalt, Gabbro, Porphyry or Gritstones. The specified aggregate shall be crushed, double washed, and shall meet the following gradation requirements:

GRADATION Sieve Size 75 Percent Passing

Backer Rod

The backer rod shall be a closed cell, foam expansion joint filler, capable of withstanding the elevated temperature of the polymeric binder. The backer rod shall have the following typical physical properties using a 2” specimen and test method ASTM D545:

Density: 2.0Lbs/Cu.Ft, min Tensile Strength: 30 psi, min. Compression: 5 psi @ 25%, min Water Absorption: 0.03 g/cc by weight, min (1% Max) Temperature @ 410°F (210°C) No Melti ng

Bridging Plate

The bridging plate shall be a mild steel plate, ¼” thick by 8” wide, cut in 4’ lengths. Spike holes shall be drilled on a longitudinal centerline at 1’ intervals.

INSTALLATION CREWS

The THORMA-JOINT system is to be installed only by factory trained and certified installation professionals.

EQUIPMENT

The equipment will consist of:

1. Small walk-behind dry cut saw
2. Pneumatic compressor of 185 CFM capacity.
3. One Hot-Compressed Air Lance (HCA Lance), capable of delivering flame retarded air stream with a temperature of 3,000°F (1648°C), at a speed of 3,000 feet per second.
4. Rotating vented or un-vented drum type mixers with a Hot-Compressed Air Lance (HCA Lance), or a pressure – air injection torch (PAT torch).
5. Melter unit equipped with agitation and an automatic temperature control which can accurately maintain the material temperature from 100°F -650°F (38°C -343°C). A thermometer to monitor the material temperature must be provided. The burner system shall have a safety pilot capable of shutting off the gas supply in the event of a flame-out.
6. 100 lb. bottles of propane
7. Vibratory roller or plate capable of compacting up to 1” in one pass.
8. Hand held calibrated digital temperature sensor.
9. Chop-saw with carbide blade, if needed.
10. Sandblasting equipment.
11. Safety clothing and equipment as required by OSHA.

INSTALLATION PROCEDURE

The following procedures are to be followed to ensure a successful installation:

Note: Thorma-Joint must be installed at a minimum depth of two inches (2”) in order to perform correctly.

Marking out: The Thorma-Joint system shall be located centrally over the deck expansion gap or fixed joint and marked out to the recommended width of 20”.

Excavation: The joint shall be excavated by the use of saws and pneumatic hand tools. Where possible, saws shall be set to cut the full required depth of the wearing surface and any membrane present. Variations in the depth of the wearing surface across the road should be considered to insure, where possible, that the deck is not damaged. All debris from the excavation channel shall be removed to allow the full volume of new joint to be installed.

Cleaning: The entire channel must be thoroughly cleaned and dried. Small debris will be removed by using compressed air. A sandblaster will then be applied throughout the length of the channel, to clean any remaining debris on the vertical walls and adjacent deck area.

Repairs: Spalled and defective concrete should be repaired with an approved material as agreed upon by the Project Engineer.

Caulking: The gap shall be caulked with the backer rod, allowing for approximately 1” of binder in the gap on top of the rod. If the previous caulking is intact and will hold the binder, it may be used to take the place of the backer rod. A small amount of hot binder should be placed onto the caulking to insure that the gap is adequately plugged.

Tanking: Immediately after cleaning and caulking, the entire channel shall be coated with a thin layer of hot binder. If significant delay occurs, the channel shall be inspected to determine if re-cleaning is necessary.

Plating: The gap shall be bridged with the steel plates centered over the gap by placing locating pins in the centerline of the plate. There must be at least 2” between the edge of the steel plate and the wall of the channel. Once the locating pins are in place, the top of the plate shall be coated with a thin layer of hot binder.

Aggregate: The aggregate must be heated in a vented (preferred) or un-vented rotating drum mixer by the use of a hot compressed air lance (HCA Lance), or a pressure air injection torch (PAT torch). Once the aggregate has been heated to a temperature of 370°-380°F (188°-193°C), it is then coated with a small qua ntity of binder. One gallon of binder per 100 lbs. of stone should be sufficient to coat the stone.

Binder: The binder shall be heated to the recommended pouring temperature, 370°-385°F (188°-196°C). At no time shall the recommended safe heating temperature of 400°F (204° C) be exceeded.

Material Installation: Layers of hot pre-coated aggregate not more than 2” thick shall be placed in the channel and immediately covered to the level of the coated aggregate. This will ensure that the 3:1 weight ratio of aggregate to binder has been achieved. Layers shall be raked to insure the aggregate is completely coated and that all air pockets are eliminated. This process shall cease approximately three-quarters of an inch (3/4”) from the top of the channel.

Surface Layer: The surface layer shall be applied as other layers except that the pre-coated aggregate is not flooded with binder. The pre-coated aggregate shall be transferred to the joint and leveled slightly higher than the adjacent road surface. On a standard 2” deep joint, the topcoat should be one quarter inch (1/4”) higher than the road surface. Deeper joints will require higher levels before tamping.

Compaction: Compaction should take place after the joint has cooled to approximately 225° F (107°C). The joint surface shall be made approx imately level with the existing road surface by using the vibratory plate or roller.

Top Coating: After compaction, lines of 3” tape are placed one inch beyond the joint width on each side of the joint to insure evenness of appearance. The joint and at least one inch of the road surface shall be top-coated with the hot binder until the surface is smooth and absent of voids. Note: If it is impossible to topcoat the joint during the same working day/night, it is allowable that the topcoat step be completed on the next working day/night. However, the surface must be cleaned, dried, and heated with the HCA Lance.

Surface Dressing: Immediately after top-coating, an anti-skid material is spread evenly over the joint to eliminate material tracking.

Final Preparation: Prior to departure the crew will insure that the entire work area is clean of debris.

Temporary Joint: In the event of a work stoppage while constructing a joint, the following procedure can be used for low ADT roadways (<20,000). Fill the cavity with cold uncoated aggregate to the level of the road surface and top the aggregate with binder to form a temporary riding surface. Roadways with an ADT greater than 20,000 will require materials similar to a cold patch asphalt. Be sure whatever is used is approved by the controlling agency.

QUALITY CONTROL

Upon request, certifications of the materials will be provided.

The Project Engineer may require the contractor to provide samples during the course of the work for laboratory test of any or all of the properties specified.

Quality of every THORMA-JOINT system will reflect the quality put forth by Dynamic Surface Applications and shall receive the highest priority in contractual obligation.

EVIDENCE OF COMPLIANCE

Dynamic Surface Applications is prepared to provide with its bid evidence of successful installations of this system over the past several years.

Please call DSA at 800-491-5663 with any questions.

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PRODUCT DESCRIPTION: Thorma-Joint is the original asphaltic plug expansion joint system. Introduced to the US market by DSA, Ltd. in the late 1980's, it continues to be first choice among bridge engineers seeking a cost effective reliable joint system for low movement structures. Thorma-Joint is a combination of BJ Super® (a polymer modified asphalt binder), specifically graded ¾”aggregate, A36 mild steel plate and heat resistant backer rod. When installed properly and according to DSA's specifications, Thorma-Joint is capable of withstanding up to 2” of cumulative movement and providing a water tight seal to protect the bridge deck and sub structure.   Resistant to puncture by foreign objects   Will not work its way out of joint cavity   Uses no metal armors that may come loose and endanger driver safety   Watertight and smooth riding   Requires no maintenance   Highly durable and proven track record   Only product of its kind guaranteed by manufacturer for 3 years   Installed in the United States since 1989 and throughout the world since the late 1970’s   Quality controlled installation by DSA or factory trained certified installers   All materials independently tested to ASTM D6297-01 standards

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