Among the commercially manufactured materials available in today s market are materials for structural repairs, floor toppings, high strength non-shrink grouts, manhole and sewer lining mortars and other specialty materials. Each of these materials has unique characteristics, which must be well understood to insure a successful application. In general, most materials need to be of a flowable or pourable consistency for successful pumping. This means that if the material can be poured out of a pail or bucket, it can likely be pumped. The exception to this requirement is repair mortars, which tend to be mixed in a thicker consistency and require special pumping techniques.
Some materials contain accelerating admixtures to reduce the setting time.
This is particularly true of repair mortars and other spray applied materials so that strength gain can be fairly rapid. It is important to keep moving when using these types of materials. Once the material is mixed, it must be pumped immediately and kept in motion and subsequent batches must be mixed and pumped as rapidly as possible. Any delays in the application process could result in plugged hoses and equipment. It may even be necessary in some cases to cool the material, the mix water, or even the hose itself.