479 SECTION 623 PNEUMATICALLY APPLIED MORTAR OR CONCRETE (SHOTCRETE)
623.1 -DESCRIPTION : This work shall consist of repair of concrete structures, protection of structural steel, or any other type of work as may be designated on the Plans by applying one or more layers of concrete conveyed through a hose pneumatically projected at a high velocity against a prepared surface in conformity with the dimensions and design shown on the Plans. It shall include removal of all loose, soft, honeycombed, and disintegrated concre te, the preparation of the surface, the furnishing and placing of reinforcing steel including wire fabric, dowels, and any other steel items noted on the Plans, and the mixing and applying of shotcrete as outlined in this sub -section.
623.1.1 -Definiti ons: Dry-mix shotcrete -Shotcrete in which the mixing water is added to concrete materials at the nozzle. Nozzleman -Craftsman on shotcrete crew who manipulates the nozzle, controls consistency with the dry process, and controls final deposition of the m aterial. Shotcrete -This is mortar or concrete conveyed through a hose and pneumatically projected at high velocity onto a surface. Wet-mix shotcrete -Shotcrete in which all the ingredients, including water, are mixed before introduction into the deliver y hose; compressed air accelerates to the material flow at the nozzle.
623.2 -MATERIALS : Materials shall meet the requirements specified in the following Sections, Subsections, o r Standards and other requirements as noted below:
MATERIAL SUBSECTION OR STANDARD Accelerating Admixtures 707.13 Air-Entraining Admixtures 707.1 Coarse Aggregate 703.1, 703.2 Curing Materials 7076. -707.10 Fibers* ASTM C1116 Fine Aggregate 702.1 Portland Cement 701.1, 701.3 Supplementary Cementitious Materials** 707.4 Reinforcing Steel 709.1, 709.3, 709.4 Water 715.7 Water Reducing Admixtures 707.3 Water Reducing, Accelerating Admixtures 707.14 Water Reducing, Retarding Admixtures 707.2 * ASTM C1116, Type II or III. Provide a minimum dosage of 1.5 pounds per cubic yard. Use fibers that are a minimum of ½ -inch length, monofilament or collated -fibrillated microfibers. ** The use of a supplementary cementitious materials will not be permitted when a blended hydraulic cement is used.