Pumice Testing Tips

We get it: it’s all about results. And nothing provides a better indication of how our pumice powders, sands or aggregates will add value to a product or process than rigorous testing.

If you would like to put our pumice through some tests, we’re here to help you in anyway we can. When possible, we have also made available the research done by others using our pumice—you'll find that list on our Pumice Information Downloads page.

Request a testing sample via our Pumice Sample Request Form and select from the available options. If you'd like our advice on selecting the best grade, give us a call. If you'd like hands-on support, that can be arranged.

HessPozz Concrete Testing Tips

The process detailed below is provided as a procedure guide when testing the performance of our natural pumice pozzolan in concrete mix designs, as the methodology is different from using fly ash or other pozzolanic-class additives.

We also have pumice pozzolan performance research reports done by the University of Utah and Washington University available to download.

TESTING INSTRUCTIONS & NOTES FOR USING HESSPOZZ
ONE: You can use Pumice Pozz (PP) as a drop-in replacement for Fly Ash (FA), if you so desire. However, since PP is considerably more reactive than FA, you will be able to use less PP and less cement, and still achieve the same level or better of chemical resistance and long-term ultimate compressive strength. For example, if you currently use 517 lbs of cement and 150 lbs of FA per yard in your mix design, you should be able to get the similar results or better with 470 lbs of cement and 120 lbs of PP.
TWO: The PP will be the same material batch after batch, day after day, year after year. You will not have to worry about changes to the chemistry or reactivity and you will never have to worry about workmen inhaling hazardous heavy metals. Neither will you need to be concerned about deleterious carbon content. Most of the difficulties of adding a pozzolan to your mix design just went away.
THREE: You will need to use a High Range Water Reducer (HRWR) to achieve the desired slump and water/cement ratio. You will be able to achieve any desired slump or even SCC, by the judicious use of a HRWR, even at W/C ratios of less than .4/1. With a PP based mix design, you will generally want to start with a higher slump than you normally would, due to the higher reactivity of the PP (vs FA). Additionally, as PP has a higher water demand than FA, which must be offset with the HRWR, your ‘workable’ time will generally be less than with a standard concrete mix, or with a FA based concrete mix design. This can be offset by additional HRWR when you reach the job site, if needed. As a general rule, particularly at W/C ratios at .4 and below, you will have about 70%-80% of the workability time as compared to a standard concrete mix design. For w/c ratios of .45/1 or greater your ‘workability’ time might actually be greater than the standard mix as excess water retards the low-heat pozzolanic reaction. It is suggested that you start using the PP based concrete for local or medium distance jobs until you have had a chance to become familiar with the characteristics of this new (but higher performance) mix design. Once you are familiar and know how to handle it and control it, you will be able to pour it anywhere.
COLOR CONSISTENCY: The PP is the same color every load. You will not have shifting shades of gray in your concrete due to the shifting color of your FA. The PP is very consistent.
COST: The PP is more expensive than the FA, but not by much. The PP is non-toxic and non-hazardous. It is a superior product; the original pozzolan, and still the best.
If you would like assistance in working up your first batch, give us call:
(208) 766-4777 x111  •  rd@hesspumice.com
[DOWNLOAD TESTING INSTRUCTIONS]

SUPPORT FROM A PUMICE EXPERT

If you find you have questions...either before or during the testing process, a pumice expert is only a phone call away.

(208) 766-4777 x111  •  rd@hesspumice.com

We have provided an online sample request form to expedite the processing and delivery of your pumice sample.

Hess History WallPumice experts since 1958.

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testing samples of Hess Pumice powder, sand, or aggregate We'll send you a testing sample of Hess Pumice at the grade you need. 208.766-4777  •  Malad City, Idaho 83252
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HESS POZZ and HESS ULTRAPOZZ
PUMICE STORE
ULTRAFINE POZZOLANIC CEMENTITIOUS GROUT
HESS PERLITE
PONICS STONE™ (SOILLESS GROW MEDIA)
SOILROX™ (HORTICULTURAL PUMICE)
LIMESTRONG™ (OLD-WORLD PLASTER)
THE IDEAL FLY ASH REPLACEMENT
PUMICE AND CONCRETE
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