- (a) Sand and cement grout. This mixture should consist of cement, sand, and water, in the proportion of one (1) bag of cement (ninety-four (94) pounds) and an equal volume of dry sand to not more than six (6) gallons of clean water.
(b) Neat cement grout.
- (1) This mixture should consist of one (1) bag of cement (ninety-four (94) pounds) to not more than six (6) gallons of clean water.
- (2) Additives up to six percent (6%) by weight to increase fluidity may be used.
(c) Concrete.
- (1) This mixture should consist of cement, sand, aggregate (gravel), and water in the proportion of one (1) bag of cement (ninety-four (94) pounds) and an equal amount of dry sand and aggregate and clean water.
- (2) Concrete can be used in the top ten feet (10’) of the annular space around the casing of the large diameter wells when the annular space is larger than two inches (2”) from the outside of the casing wall to the face of the bore hole.
- (3) Aggregate shall be no larger than one-fifth (1/5) of the dimension between the outside casing and the face of the bore hole.
- (4) All concrete shall be placed to prevent voids.
(d) Bentonite grout.
- (1) Bentonite or sealing clay grout is a manufactured clay product that expands in contact with moisture to form a seal that prevents the movement of water and may be used in consolidated and unconsolidated formations.
- (2) It is the responsibility of the contractor to make the viscosity of the bentonite thick enough to seal out all contaminates.
- (e) Grouting of metal-cased wells. Metal casing shall be encased in a cement seal at least two inches (2”) thick from ground level to a distance of at least ten feet (10’) below established ground surface.
- (f) Grouting of curbed wells. Curbed wells shall be concreted at least six inches (6”) thick poured monolithically from the upper terminal to a distance of at least ten feet (10’) below established ground surface.