Zenith C-30HDG manual 30HDG Pump General Information, Pump Mix Guidelines

C-30HDG PUMP — GENERAL INFORMATION

The following operating principles and operating suggestions should prove helpful in the successful operation of your concrete pump.Your new “small line” concrete pump has been designed to give you many years of service when operated properly. A study of the following paragraphs is important to the successful operation of your new Direct-flow Concrete Placer.

All concrete pumps require a high level of operator skill and more frequent service than most of the other construction equipment.The highly abrasive nature of concrete under pressure makes it extremely important that expendable wear components be inspected at regular intervals between jobs to prevent having to replace these items during a pour.

Experience has proved that inconsistency of batched concrete mixes and frequent moving of the line requires the operator to be readily available at all times during pumping to stop the pump and prevent abuse to the unit which may occur if unexpected blockages develop.

Pump Mix Guidelines

When ordering concrete, be certain to advise the concrete supplier that you require a “pump mix”. The Direct-flow manifold will pump a wide variety of materials, but certain basic principles must be followed to assure successful pumping, as follows:

Generally speaking, the washed concrete sand and #4 aggregate (pea gravel) should conform to A.S.T.M. standards in regard to sieve analysis. Sands in some areas are washed clean of the #100 and #200 mesh fines, which results in separation and jamming in the manifold while pumping under pressure.

If this condition develops, check with your concrete suppliers engineers and get their recommendations for supplementing the lack of the fines.The use of locally accepted ad-mixes may be required.(For example, Pozzolith, Bentonite Clay, Plastiments, etc.) When properly prescribed, additives form the plastic paste sometimes necessary to hold the cement and aggregate together.

If jamming conditions in the pump or hose occur for any reason at all, do not attempt to use more power to correct the condition.

Determine the cause of jamming, correct it and resume pumping. Trying to force material through under jammed conditions may result in damage to the drive system, thus voiding any warranty services.

As a general rule, the use of approximately six sacks of cement, 70% washed concrete sand and 30% #4 pea gravel per yard of concrete will result in a pumpable mix.The ideal nature of sand and rock in certain areas may permit you to increase the percentage of rock or adjust the mix considerably to meet the job requirements.When possible, you may experiment with various mixes in your area to determine the degree of versatility of the Direct-flow Pump.

Uniform gradation of the washed concrete sand and the 1/2” minus aggregate along with sufficient cement content and water are important to a successful pump operation.

A recommended pumpable mix design would be 70% sand and 30% aggregate-cement content to be a minimum of 6 sacks. (564 lbs.)

Your local sand and rock engineers will give you the S.S.D. weights of sand and rock required in your local area which will yield one cubic yard per the above recommendation.

Sample Design Mix - 3000 Psi 3/8 in. Slump 4- 5 in.

Type II Cement	6.49 sack/cu. yd	611 lbs.
Sand	Sat. Surf. Dry	2000 lbs.
#4 Gravel	Sat. Surf. Dry	864 lbs.
#3 Gravel	Sat. Surf. Dry	0 lbs.
Water	48 Gallons	400 lbs.
	Total Weight	3,906 lbs
AdmixtureWRDA-79		26 oz.
Water 7.40 gal/sack

Test laboratory data has proven in many areas that the above mix guidelines have produced concrete rated at 3000 psi (28 day test) and upwards of 5000 psi with an increase in cement.

In some areas where the gradation of sand and rock is ideal and sufficient cement is used along with admixtures, the Mayco small line concrete pump will handle up to a 50-50 ratio of sand and rock.

When the mix is designed for wet gunning applications, it is normal to increase the cement (up to 7.5 or 8 sacks) and change the sand to rock ratio to 85% sand and 15% rock.

The Mayco concrete pump will valve efficiently when using cellular-foam concrete mixes upwards of 70 lbs. per cubic foot wet density. (Below 70 lbs. materials (roof decks) the valving becomes inefficient.)

PAGE 26 — MAYCO C-30HDG PUMP — OPERATION AND PARTS MANUAL — REV. #6 (04/02/12)