1. Plugging or Sealing Materials a. It is recognized that no material is completely impervious, however, experience and test show that neat cement or cement slurry has a low enough permeability to be preferred for use when plugging and/or sealing is required. Neat cement or slurry is a mixture consisting of one bag of cement to five to ten gallons of water. Under certain conditions, other materials may be added to accelerate or retard the time of setting and to provide extra bulk. If a gel or bentonite is used, the quantity added should generally vary between one and four percent. Cement grout or concrete grout may be used in place of neat cement or cement slurry if the change is approved by the Louisiana Department of Public Works or the commission. Following are definitions of cement grout and concrete grout.Cement Grout-a mixture consisting of not more than two parts of sand to one bag of cement (94 lbs.) and five to ten gallons of water.
Concrete Grout-a mixture consisting of cement, sand and gravel, and water in the proportion of one bag of cement (94 lbs.) to an equal volume of dry sand and gravel, and five to ten gallons of water.
b. Unless specified otherwise, plugging material shall be placed in one continuous operation by the circulation or pump method. The grout or slurry shall not be poured or dropped through the water.