275 SECTION 510 RE-SEALING CONCRETE PAVEMENT JOINTS
510.1 -DESCRIPTION : This work includes all labor, equipment, and material required to remove existing sealers, clean the joint, and seal the joint with a sealant meeting the requirements of section 510.2. The location of the joints to be sealed shall be as shown in the plans or as directed by the Engineer.
510.2 -MATERIALS : The joint sealant shall be in accordance with either section 7 08.3 or 708.4. The joint back -up material shall be in accordance with section 708.4.2, shall meet the requirements of the Sealant Manufacturer, and shall be appropriate for outdoor applications.
510.3 -CONSTRUCTION METHODS : 510.3.1 -Joint Preparation: All spalls along the joint which are directed by the Engineer to be repaired, shall be repaired as specified in section 506 for partial depth repair. The spalls shall be repaired prior to resealing the joint. Existing joint sealer or sealant shall be removed from the joint groove as designated by the Engineer. Where re -sealing in an area of previously installed sealant, a fresh sawcut shall be made to provide a clean face for the n ew sealant to bond. The new sawcut shall provide a joint groove of adequate width and depth to provide a width to depth ratio (shape factor), including joint back -up material, of 1:1 for hot -poured sealant and 2:1 for silicone sealant. Any damage done to newly placed sealant by re -sawing operations shall be repaired to the satisfaction of the Engineer. The longitudinal joints shall be sawed prior to resealing the intersecting transverse joints. Immediately following the final sawing operation, both ve rtical faces of the joint shall be completely free of dirt and dust; leaving a clean dry, newly exposed concrete surface. Joints shall be cleaned by sandblasting each vertical face with the nozzle held at an angle to the joint face and within one ( 1) or two (2) inches of the pavement. Sandblasting shall be done to a depth at which the sealant and backer rod are to be installed. Just prior to installing the back -up material, the joints shall be blown out with compressed air at a pressure of at least 90 psi to remove all dust, loose particles, and debris. Air compressors used for this purpose shall be equipped with traps capable of removing moisture and oil from the compressed air. A joint shall not be sealed until it is thoroughly clean and dry. After the final cleaning, the back -up material shall be inserted into the joint groove in accordance with the Manufacturer’s recommendations to provide the correct shape factor for the sealant being used.
510.3.2 -Joint Sealing: After insertion of the back -up material and prior to becoming contaminated, the joint groove shall be sealed in accordance with the Sealant Manufacturer’s recommendations. At the time of sealing, the joint groove faces shall be dry and dust free. The sealant shall be pumped into t he joint groove in a continuous uniform operation to properly fill and seal the joint groove from the bottom upward in order to avoid trapping any air bubbles. Tooling of the sealant, in order to force the sealant against the joint faces and provide a sli ghtly concave surface with a depth of approximately ¼ in ch (at the center of the joint) below the pavement surface, is required unless otherwise directed by the sealant manufacturer. When