Multiquip LS400/LS500 PUMP - PUMPING INFORMATION, Remixtures, Downhill Pumping, Hose Pulsation

LS400/LS500 PUMP — PUMPING INFORMATION

REMIXTURES

Remixtures that are designed into the concrete mix by the redi-mix company or an architectural engineering company. This section lists common admixtures and a brief explana- tion of their functions:

A.Pozzolith 300 – or the equivalent acts as a water retarder and a lubricant. On a lean mix, long pushes, stiff mixes, and vertical pushes, Pozzolith 300R helps pumpability.

B.MBVR – air entraining, acts as a lubricant.

C.Calcium Chloride – commonly referred to as C.C., is used as an accelerator.When pumping a load with calcium chloride, it is recommended that you wash out if the waiting time between delivery trucks becomes too long.

D.Super Plasticizers – acts as an accelerator. The concrete will look very wet after the super plasticizer is added, but will begin to set up very fast.Wash out immediately if you do not have a truck waiting. Super plasticizers are used mainly on commercial jobs.

E.Red Label – acts as a water retarder and an accelerator. Red label will be used mainly on com- mercial jobs.

F.Fly Ash – is used to help increase the strength of the concrete and decrease the cement content per yard. This is one of the most common admixtures used.

All admixtures will be shown on the redi-mix concrete ticket. Before starting the pumping job, ask the driver of the redi-mix truck to see the concrete ticket and note the admixtures that exist and take the proper action.

DOWNHILL PUMPING

Downhill pumping can be a difficult procedure on some jobs. The slurry procedure would be the same as explained PrimingThePumpWithSlurryMixture sectionofthismanual. It is suggested that a sponge approximately 2”x 4”x 6” in size be placed in the hose before the start of pumping.

Wet the sponge before placing it in the hose to keep the slurry from running too far ahead of the concrete, which will reduce the possibility of separation.When the pump is stopped, the material can flow slowly down, due to gravity, and cause the hose to collapse.

When pumping is resumed, you can expect blockage at the point of hose collapse. To prevent this from happening, the hose can be“kinked off”at the discharge end when the pump is stopped to prevent the gravity flow of the material in the hose.

The use of stiffer mixes when pumping downhill will decrease gravity flow of the material in the hose and will assure a smoother operation between the cam roller bearing and cam plate. As with any job, make sure that the hose and the couplings are in good workable shape.

VERTICAL PUMPING

When pumping vertically up the side of a building, above 40 feet, we would recommend the installation of steel pipe securely fastened at intervals as necessary to support the pipe. Ninety degree, long radius pipe sweeps should be installed at the top and bottom of the steel line.

Use a 25 ft. hose, or short section, off the pump; and for the balance of the horizontal distance to the vertical line, use steel pipe. This type of installation has been satisfactory on many jobs being pumped in excess of 100 feet high. Line pressures are always less using steel pipe as compared to hose.

When pumping vertically, using all hose, it is recommended not to go higher than 50 feet with hose. The hose should be tied off at intervals of 10 feet, if possible. Special attention should be given when tieing the hose off at the top as the hose will have a tendency to stretch when filled with concrete.This will increase the possibility of a blockage at the point where the hose is tied off. To avoid this, a long radius of 90º elbow is recommended. The suggested place to tie off is on the hose, under the clamp.

It is strongly recommended that steel pipe be used on all vertical pumping for safety and convenience.

HOSE PULSATION

A slight pulsation of the hose will always be noticeable near the pump. Excessive pulsation of the hose near the pump is normallyduetohigherthanaveragelinepressurescausedby stiff, harsh mixes, or extremely long pumping distances.

PAGE 32 — MAYCO LS400/LS500 PUMP — OPERATION AND PARTS MANUAL — REV. #6 (09/19/11)