Forum Message



Name: Daniel  Johnson
Heading: 1.1.2.1.2.1.1.2.1.1.1.1.1.1.1.1RE:Manufactured Sand Presentation
Message:
I am preparing for a presentation for the annual fall meeting of the Dallas Chapter of the American Concrete Institute. The title of the presentation will be “Manufactured Sand - The Future Fine Aggregate.?” My emphasis will be on utilizing a manufactured sand with a lower fines content (particles passing the 200 mesh) rather than the high fines content as presented by ICAR. I am looking for examples of concrete utilizing just manufactured sand and not a mix of natural sand with manufactured sand. If you know of anyone using manufactured sand to make a concrete, please let me know. As they say, a picture says a thousand words.

Any help would be appreciated.


Jay Lukkarila

ICRUSHROCK@aol.com or
ICRUSHROCK@gmail.com



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Jay Lukkarila


Jay;
I suggest you contact Tim Folks at Hawaian Cement. 808 483 3300. I know they use a lot of manufactured sand, they do blend some Maui Beach sand but perhaps not in all mixtures. Certainly they primarily use manufactured sand all their mixes.
"Doc" Watson


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Watson


Doc -

Thanks a lot. I'll give him a call next week. I'm trying to talk the ARI in sending me to Hawaii so that I can get those truly significant, everyday pictures with comments from the everyday people about concrete made everyday with manufactured sand. I did have a blast at the ICAR conference (Thanks again ARI and you're band of merry men). It was like being a kid in a candy store. Everyday there was like Christmas for me. I ran out of time to talk to everyone I wanted to and there was probably a few that wanted me to go away. Not only was there people from all over the U.S. there, I personally met and talked with people from five different countries - some as far away as Sweden and many from as close as Canada - and they all had something really interesting in their experiences and research to share that wasn't part of the structured conference.

I was surprised to see in the Aggregate's Manager's state by state summary of the USGS's findings that Hawaii actually had one sand and gravel deposit shown. I also noticed that the USGS's information is not quite accurate, as sand and gravel deposits are still shown which sell sand and gravel, but no longer mine it. There were also examples of names of quarries listed which had already changed hands twice by now. Thirdly, there were sand and gravel pits that were not shown.

It is interesting in Hawaii, that each island has a basalt that varies in characteristic's from each other. Each basalt behaves differently and each island has it's own aggregate specifications for concrete.

I recently asked one of my daughters on a proposed trip to Hawaii to go to few quarries and pick up some basalt samples and hit a few concrete projects and talk to some quality control people - she's in the pre-med program at Long Beach State and didn't sound too confident with the request.

The quest continues . . .

Jay

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Jay Lukkarila


Jay and all,

As the sand and gravel commodity specialist I might be rather upset to find that we have inaccurate data regarding aggregate mining in Hawaii. However, I'm only mildly upset because I am not surprised. At the USGS we mainly collect information one of two ways. We send surveys to all known producers in HI. If the company sends back a reply then we assume they know what they are doing and list them as a producer. If they do not reply we check the MSHA listings to determine if they operated, how they are classified (sand/gravel OR quarry), and we use the number of manhours to estimate production. We also pick up new producers from the MSHA listings. We do call producers when we are able (its impossible for us to call over 10,000 locations each year) to clarify situations. We recently spoke with Hawaiian Cement to clarify their activities but it seems we may not have done a good job. We at the USGS are happy to have feedback on our reports and data. If Jay would like to give us his critique of the 14 operations listed in the Aggreates Atlas for Hawaii we would be happy to try to get it right for the next time. Of course, the MSHA site is not always accurate and in the future our reliance on their information can get us on the wrong track again.

Anyone out there that would like to assist us in getting it right for any state or any aspect of our publications is welcome to contact us. My email is wbolen@usgs.gov

We really do try to keep it all straight but situations, definitions (is it sand and gravel or crushed stone, for instance, and limited resources often work against us.

I would also like to thank Jay for all his contributions to this forum. I have enjoyed the discussions and comments, answers and questions.
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wally bolen


Jay

We make concrete from 100% recycled aggregate by crushing waste concrete, washing it, sizing and blending it and then delivering it back to market in volumetric trucks. That's the closest we get to 'manufacturing sand'. Is this of any interest to you? We make about 60,000 m3 per year of concrete ranging from C5 to C30.

Andrew Holmes

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Andrew Holmes


Jay and All, I am from Concrete Aggregates Corp here in the Philippines, for several years now manufactured sand S1 has been used as a substitute for river sand. However because manufactured sand is coarser than river sand, it cannot be used as a substitute for all applications, in particular finishing work. To anyone interested, I will be glad to give you specifications of our products which meet strict U.S. military specs. We have supplied the U.S. base in Diego Garcia, Palau Intl Airport, Majuro Airport, all using manufactured sand.

Albert
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Alberto Villadelgado


Jay,
I was happy to see the response from CAC's, Alberto Villadelgado, of The Philippines who touched the subject "not good for all applications" and "finishing".

My experience has shown, (including Diego Garcia NAS Airfield), that 100% Mfg.Sand in paving mixes causes problems and Finishing Heartaches particularly when slipforming airport or Class A highways and meeting the new (Texas one of last)),
Rideability / Smoothness Quality Specs.

The use of 100% MS causes internal partical friction that is very hard to overcome with either ad-mixes or vibration (higher). In many cases the use of 100% MS is strickly an economic decision due the haul distance of an "oval" river sand. But the penalties for poor surface qualities, i.e. High Profilograph results, such as diamond grinding for correction and potential price reduction may far outweigh the cost of at least a 50/50 sand blend that finishes much better. The 50% river sand "Breaks" the friction factor and raises the "Finishability
Factor".
Also, forget making corrections with handtools (cutting straight edges, floats, etc.),as you go. 100% MS is almost impossible to hand finish.

100% MS is okay for formed structural works where the vibrators & forms take the finishing risk away.


You might consult with our mutual friend and Texas neighbors, Jim & Jay Shilstone about this subject.


Respectfully,
Chapin Sipherd, Retired
CMI / Terex Corp.
"Concrete Guru"
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Chapin Sipherd


Hello Chapin

I disagree with your comments that MS is is almost impossible to finish and is generally a poor performer in concrete. This maybe true for the MS that as delivered to your site. The term MS is used so loosely that it generally is all encompassing of any sand produced from crushing and screening. There are cowboys out there flogging off their crushing scalps as a MS. Quality does not even enter the equation. This approach has given MS a bad name and an image problem in many markets, especially the US.

We have consumers that use 100% manufactured sand that is used for shotcrete and they love it, it out performs the natural sand that they were using and provides them with cement and transportation savings. Mr Alan Kirby would be able to give you guidance from his experience where he has used 100% MS for concrete and shotcrete on a large civil engineering project and had no problems. There are some that are also using high amounts of minus 200# and getting a good result. The difference between what you got supplied and what our customers supply is the quality.

Metso Minerals(for whom I work) is working to improve the name of manufactured sand, many of our global markets are using increased amounts of MS in concrete. This we understand is a long long long road considering the poor MS practice that has occurred in the past. However we are hoping to achieve the unachieveable. So before making wide sweeping statements about the performance of MS, please understand the issues that surround this already sensitive of subjects.

Cheers
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Stacy Goldsworthy


Touche Stacey, MS is not as simple as most people understand it to be. That is why I pointed out the two main kinds of MS, washed & unwashed. Besides being an aggregates supplier, we also produce ready-mix concrete and asphalt. We supply MS and aggregates based on the specifications of the customer and can adjust plant settings so as to conform with their needs.It would be better if we spoke of specific specs requirements, job mixes, compressive strenght targets, etc. Ready mix and asphalt batching plants have numerous alternatives and options to allow optimum use of MS and it would be much better if there was more coordination between aggregates suppliers and batching plants/specifiers as this is what we do here in the Philippines.
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Alberto Villadelgado


Hello Alberto,

You hit the nail on the head when do say that there needs to be more coordination between aggregate suppliers and ready mix/precast operations. We (Metso) are now attending the Concrete trade shows to discuss MS with our customers customer.

Grading and particle shape are also key issues in the use of MS, it is the influence of these that determine what the performance will be. For the crushing and screening operation that you operate the two MS products are washed and unwashed. For many of our customers there are range of MS of varying quality depnding on where in the circuit they are taken. Operation of medoium/fine liners in cone crushers requires that fines be scalped to prevent chamber packing. These fines are of poor quality and are typically added to the waste fines stockpile, or sold as low value materials. Use in concrete gives very poor performance. In some circuits the use of EF cone crushers and impactors can produce a high quality MS that will give good performance in concrete.

The source rock influences the degree of shaping that can be achieved and the production of fine sand particles which are critical for concrete. There are a number of variables that influence the result. You are ahead of most when you mention that you are using high fines. Could you tell me what crushing equipment is used to produce your MS.

Cheers,

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Stacy Goldsworthy


Stacey, been quite busy,we use Sandvik equipment, we are about to install a Barmac to further improve our products and capacity.

Alberto
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Alberto Villadelgado


Jay, Stacy, Alberto:

CHEERS,

I have no quarrels with any of your statements regarding "Quality Control",
"Particle Shape", ETC. All are important.
However, it would be beneficial to your experience library if you could tour a major
airfield (Runways & Taxiways)project to witness the processes in paving. The same would be true of a major highway(mainline) project.

In these cases concrete is produced (normally at site)by central-mix plant in rates of 300-500 cy/hr. The volume required for these projects range 10,000-100,000 cy of concrete with strength requirements of 650psi(highway),850psi(FAA Airports); Flexural Strength, 1/3rd Point breakage.
The most common practices are to Pre-place
the concrete (Placer-Spreader)in front of the
slipform paver (Paver-Finisher) in the volumes above. Paving depth ranges from 12-14" for highways and 18-24" for air fields.
The concrete is delivered @ 1/2" to 1" slump,
(it won't stand-up or reach the strength requirements. Edge slump is less than 1/4".
Surface tollerence is 3mm or less-continuously for acceptance.
The use of 100% Mfg.Sand,(MS) (High Quality,
Clean, Cubical Shape in the minus #4 through the minus #50 and no more than 3% #200) makes this construction process very, very difficult. If the MS has elongated particles
forget it. Not only finishing problems but strength problems to boot.

This type of concrete construction is different than "Shotcrete" or "Type-A Formed
Structural concrete construction. Patios & Driveways, most City Streets are excluded. The world of concrete construction has many, many neuances and differences not only in usage but geographically also.

I rest my case.
Repectfully,
Chapin
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Chapin Sipherd


Chapin,

It's kind of funny, Chapin, because if anyone is motivated to make manufactured sand work in concrete, it will be the large highway contractor.

What if a large highway contractor figured out how to use a manufactured sand created on-site for his portable concrete plant instead of hauling a natural sand from a hundred miles away? What if he needed 300,000 tons of sand and saved $10.00/ton by creating a usable manufactured sand on the job site?
Would this knowledge win him the job or just save him a lot of money? What if Contractor A perfected the science behind making a quality concrete using any manufactured sand? Would he have an advantage over Contractor B, C, and D who were limited to natural sand only?

I have made manufactured sand work for concrete many times, in many places, and never did I have any strength issues. I look forward to the opportunity of making it work on a project where you have to dump a few thousand truckloads of it in front of that big yellow machine.


Respectfully,

Jay Lukkarila

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Jay Lukkarila


Jay,
Thank you for your well thought comments.
You are absolutely correct in the usage of the elements of "QUALITY" AND "ECONOMICS".

These are the drivers of our business (any
business, really)of constructing the World's Highways and Airports.

MY concern is the "WHAT IF's" in your discussion. If we can make the what if's into "LET'S DO IT's, I'm all for it.
Go For It!!!
Don't forget the cavats that come with
"What If's"

Respectfully,
Chapin
PS: Since we're both in Texas, let's do lunch or tea !!
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Chapin Sipherd


Chapin,

Around ten years ago I was lucky enough to get on a large dam project with group of people who were "out of the box." We had six months to test every crusher in the world, all of the crushers under production circumstances. We were successful on three major "what if's" and turned them into reality which saved the contractor over 16 million dollars in a two year period. We designed, built, and operated, a state of the art aggregate plant that produced manufactured sands that passed filter sand specifications, ready mix concrete specifications, and roller compacted concrete specifications. It was from this experience which started my crusade to bridge the gap between the aggregate suppliers, concrete consumers, and government regulators.

The question in my mind is not "what if" - it's more like "when."

Texas is the largest stone producing state in the U.S., thus the largest manufactured sand producing state. It is my opinion, that Texas and California have the most to economically to gain, by creating new specifications for manufactured sands for concrete. (California's construction markets are booming and major regions of California are out of natural sand and the Sierra Club has not given out their opinion as to where to dig next.)

I'm available for lunch, tea, beer, or Bar-B-Que. I got my recent fix of Bar-B-Que on a trip to San Antonio, lovely city that uses a blend of manufactured sand and natural sand which makes an excellent concrete. They may not be motivated to change, but regions such as Dalls might.

As a hobby, I make statuary concrete in my garage using bright white, 100% manufactured sand. I literally, live, eat, and breathe the stuff. In certain applications, I add a significant quantity of my own mineral admixture which is a clay like material of 10 to the minus 5 in size. Makes excellent concrete.

Looking forward at meeting you and many others.

Jay

ICRUSHROCK@aol.com
ICRUSHROCK@gmail.com

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Jay Lukkarila


Jay -- Master Enterprises (Empresas Master) in Puerto Rico has been using mix designs with 100% manufactured sand since at least 1994. They have been very successful, and experimented with high fines manufactured sand to reduce cement costs as well. They have aggregate plants that produce manufactured sand from limestone and from basalt, so have experimented with different types of manufactured sand. Puerto Rico has limited natural sand resources as do many island economies, and necessity is the mother of invention so there are other concrete producers who have replicated that success.
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Daniel Johnson
 
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