ITEM 726 - COAL TAR SURFACE TREATMENT

726.1 Description

            This item shall consist of a surface treatment on an asphalt concrete pavement using a coal tar asphalt rejuvenator/sealer on previously prepared surfaces in accordance with this Specification for the areas shown on the Plans or as designated by the Engineer.

The asphalt pavement rejuvenator/sealer consists of a blend of coal tar and petroleum oils. It is designed to penetrate the pavement surface to replace critical elements necessary to rejuvenate and rehabilitate the asphaltic binder thereby increasing pavement plasticity and flexibility while reducing viscosity. And, since it already became an integral part of the pavement, it does not wear off under traffic such as chipping, peeling, flaking or delaminating.

726.2 Material Requirements

The coal tar asphalt pavement rejuvenator/sealer is a patented complex blend of coal tar, solvents and coal tar oils meeting the requirements detailed below.

The coal tar asphalt pavement rejuvenator/sealer is composed of the following range of materials:

Materials	Range
1. Refined Coal Tar (Grade RT-12) 2. Light aromatic solvent naptha or coal-tar solvent naptha 3. Blend of tar oils as described below meeting requirements of Table 1 4. Elastomer	30% - 50% 30% - 40% 15% - 40% 0.01% - 13%

            The coal tar oils are a composition for rejuvenating asphalt pavement comprising of a mixture of di-, tri- and tetracyclic aromatic compounds and. their alkyl homologs containing lower alkyl groups together with significant amount of phenolic and hydroxyl derivatives. The said mixture which is derived from the distillation of coal tar, has the following characteristics:

            Specific Gravity at 25/25°C, min.                           1.06

Brookfield Viscosity at 25°C                                   60

Initial Boiling Point °C, min.                                   108

Continuous Boiling Range °C, min.                    300

1. The coal tar pitch shall conform to the requirements of ASTM D 490, Grade RT-12.

2. A. Light Aromatic Solvent Naptha:

            API Gravity at 16°C                                                  11 – 30

Specific Gravity 16/16°C                                         0.876 – 0.993

Distillation Range, °C                                             155 - 233

IBP (initial boiling point), °C                                   180 - 300

DP (dry point), °C                                                     45 - 122

Flash Point, °C/TCC                                                45 – 122

    B. Coal tar Solvent Naptha:

            Specific Gravity 16/16°C                                         0.94 - 0.099

Distillation Range, °C                                             122 - 199

Initial Boiling Point, °C                                            35 - 44

Flash Point, °C/TCC                                                35 – 44

Table 1 - Coal-Tar Oil Properties

	Requirements	Test Method
Specific Gravity@ 25/25°C, min. Water % by weight, max. Brookfield Viscosity @ 25°C, max. Soluble in CS2 by weight, min. Flash Point COC min.	1.06 2.0% 60cps 95% 82°C	ASTM-D 86 ASTM D 86 ASTM D 86 ASTM D 86 ASTM D 86
Distillation, 160°Clnitial Boiling Point	Requirements, %	Test Method
180°C 190°C 200°C 210°C 220°C 230°C 240°C 250°C 260°C 270°C 280°C 290°C 300°C	0 – 2 0 – 3 0 – 4 0 – 5 0 – 6 0 – 8 0 – 12 0 – 20 5 – 30 10 – 40 15 – 50 20 – 60 25 – 60	ASTM D 86 ASTM D 86 ASTM D 86 ASTM D 86 ASTM D 86 ASTM D 86 ASTM D 86 ASTM D 86 ASTM D 86 ASTM D 86 ASTM D 86 ASTM D 86 ASTM D 86

Table 2 - Bituminous Material Properties

Test Property	Requirements	Test Method
Specific Gravity@ 25/25°C, min. Viscosity Engler 50 cc @ 50°C, max. Water % by volume, max. Distillation % by weight    170°C, max.    270°C    300°C Flash Point, min. PMCC, °C Softening Point of residue from 300°C distillation test	1.04 4.5 2.0 20 25 – 45 30 – 55 51.66°C 40 - 55°C	ASTM D 70 ASTM D 1665 ASTM D 95 ASTM D 20 ASTM D 93 ASTM D 36

726.3 Construction Requirements

726.3.1 Weather Limitations

The sealer/rejuvenator shall be applied only when the existing surface is dry and the air temperature is at least 10°C or higher and rising.

726.3.2 Equipment - The Contractor shall furnish all equipment and hardware necessary for the performance of the work. The product shall be delivered in dedicated tankers and/or containers with fillers. The distributor shall be designed and equipped as follows:

a.         Adequate heating capacity for rapid heating of the sealer rejuvenator to the proper application temperature.

b.         A positive displacement pump capable of pumping low viscosity material and providing a pre-selected constant pressure of 138 KPa - 413 KPa to deliver the specified rates of application.

c.         A full circulation spray bar and applicator which maintains proper nozzle that can provide the specified rate of application.

d.         A hooded spray bar and applicator which maintains a proper nozzle height.

e.         A positive shut-off for the spray bar.

f.          A hand spray, with hose, equipped with a positive shut-off at the spray gun.

g.         A thermometer installed in the distributor tank to measure the temperature of the sealer/rejuvenator at the time of application.

h.         A tachometer calibrated to a minimum of tenths of miles per hour.

i.          A chart listing the capacity of the tank, in liters, shall be earned each unit. This chart shall allow liters for each 2.54 cm of depth. A chart showing speed pressure application rates will also be included.

j.          The distribution shall be equipped with filters which shall be fully functional during both the loading and unloading of the product.

726.3.3 Cleaning Existing Surfaces - Prior to placing the sealer/rejuvenator, the Contractor shall clean the surfaces of the pavement to be treated and assure that it is free of all debris, dust, dirt or other loose matter.

726.3.4 Application - Prior to full production the Contractor shall place one or more test sections on a surface selected by customer and Contractor at various application rates to develop the proper rate. The coal tar pavement rejuvenator/sealer is applied evenly with a specialized bituminous distributor approved by manufacturer-authorized contractor at the rate so determined. The application temperature shall be between 21°c and 35°C.

726.4 Method of Measurement

The quantity to be measured and paid for shall be the number of square meters of pavement applied with the coal tar pavement rejuvenator/sealer as shown on the plans.

726.5 Basis of Payment

The accepted quantity measured as prescribed in Section 726.4, Method of Measurement shall be paid for at the contract unit price per applied square meter of pavement dressing conditioner, which price and payment shall be full compensation for furnishing and placing all materials, including all labor, equipment, tools and incidentals necessary to complete this Item.

            Payment will be made under:

Item Number	Description	Unit of Measurement
726	Coal Tar Surface Treatment	Square Meter