Concrete Aggregate

As I understand it

And there are far better sources------
The clinker is imported, but I don't know from where at.

HB

Being that we mine construction materials on the island....

...I would say I can give you any details you want. However, since it is such a boring topic, I do not wish to place everyone at DR1 to sleep. Therefore, please send me a pm or email to dms3611@aol.com and I will be happy to tell you all you want to know.

Best, Dave

Now that's not fair!!!

Bore us, please?

What is aggregate?

Why is it boring?

And I just knew you were the one!!! to answer this one... HEHEHE

HB

Please bore US

When I want to know a topic I use the search. Some day I want to build my own house there and this is info I could use. It is not something that I need to know right now but as a DR1 junkie it is something I would read with interest. The more info that is shared in the public forum the less questions are reasked.
John

jsizemore said:

When I want to know a topic I use the search. Some day I want to build my own house there and this is info I could use. It is not something that I need to know right now but as a DR1 junkie it is something I would read with interest. The more info that is shared in the public forum the less questions are reasked.
John

Click to expand...

The same for me...
Regards Francois

OK....I will "torture you all" slowly but surely....hahahaha

Lets begin here and then expand into the questions asked (over the next day or so). I will work hard at keeping things "brief".

Aggregates, by "definition" includes all construction materials which are comprised predominantly of sand, gravel, crushed rock, clay and other naturally occurring and generally "low-value" fine grained materials. These materials are generally used to alter the properties of concrete or cement based products. Some aggregates add decorative texture, others durability, strength, or traction.

Aggregates are generally sourced from unconsolidated to loosely consolidated material, with the exception of crushed rock. Crushed and screened rock is the primary aggregate used where there is a lack of available unconsolidated screened material that will meet required specifications (Crushed rock should be used more in the DR where specifications have been "known to be ignored" (ie. rock being screened only) and mining technique accompanied by and mine & resource management (with special attention to non stop extraction of materials from active rivers & basins in the Capitol), often being POOR at best.

These materials are generally used in the construction industry, as the predominant aggregate component in concrete and asphalt and for fill and/or load-bearing purposes. They are the predominant "filler" in concrete block, pavers, concrete, precast products,and asphalt.

Aggregates for construction do not include the generally higher value-added, processed industrial mineral "aggregates" where major use is by industry sectors outside the construction aggregate industry (for example calcium carbonate, CaCo3).


"No-Doz" anyone? HB...I know you have passed out already and have hit your head on the floor.........

Colors and types of aggregates stone found in DR

The Dominican Republic has been blessed with "geology". This is probably the single least exploited resource of the nation. Therefore, there are all types of materials and "colors" to choose from for construction and manufacturing purposes. Examples include:

Colors

Black, Brown, Cream, Green, Grey, Pink, Red, Salt and Pepper, White, Blue, and Yellow.


Stone Types

Basalt, Granite, Limestone, Marble, Travertine, Quartz, River Stone, Sandstone, Silica, Coral Limestone, Natural and Manufactured (crushed) Sands & Pebble.

With the exception of that "grey ash" material that was recently imported to the DR from Puerto Rico, and some various container loads of marble brought in from Asia, the only imported "construction materials" being imported into the DR on a regular basis is "clinker"....and this is used in the process of actually creating Portland cement. All the other materials mentioned above are a "native" of Hispanola.

This is exciting stuff....isn't it? WOW!

just curious, what happens to the quarries once they have been depleted?

mob

hole in the ground

If it is anything like the US then it is just a hole in the ground. Fills with water and becomes a cold water lake. Not really a pollution problem because it was just stone in the first place.
John

Ugly eyesores generally in the DR............

....problem is with the lack of good mine management, many Dom Rep operations just go for the "easiest aggregates" to reach. When they do this, you end up with what is, in the "best case", just groupings of "ugly holes" and in the worst case extremely dangerous mine sites that are prone to "cave ins", etc. For example, next time you come down from the tunnel between POP and Santiago, look to the right just before coming to the "crossroad" of Navarrete... or look in some of the terribly managed sand mines in Santo Domingo if you happen to be flying over the city heading toward Bani).

Due to the fact that most of these mines have so much gravel and sand remaining on them, water never tends to fill up in pits in the DR (too porous/never tend to hit clay). Though many mining folks in the DR do not take the time to "reclaim" and beautify the area they have extracted from, we work hard at replacing topsoil, plant trees etc., and generally make the area we extract from productive again. In this way, our goal is always to benefit the community area from where materials are being extracted.

In the U.S. and Canada, many of these "holes" are beautified as suggested earlier, often turning them into lakes and parks. However, there are many in the states that are turned into managed refuse "fill" sites and also are being turned into golf courses!

dms3611 said:

The Dominican Republic has been blessed with "geology". This is probably the single least exploited resource of the nation. Therefore, there are all types of materials and "colors" to choose from for construction and manufacturing purposes. Examples include:

Colors

Black, Brown, Cream, Green, Grey, Pink, Red, Salt and Pepper, White, Blue, and Yellow.


Stone Types

Basalt, Granite, Limestone, Marble, Travertine, Quartz, River Stone, Sandstone, Silica, Coral Limestone, Natural and Manufactured (crushed) Sands & Pebble.

With the exception of that "grey ash" material that was recently imported to the DR from Puerto Rico, and some various container loads of marble brought in from Asia, the only imported "construction materials" being imported into the DR on a regular basis is "clinker"....and this is used in the process of actually creating Portland cement. All the other materials mentioned above are a "native" of Hispanola.

This is exciting stuff....isn't it? WOW!

Click to expand...

Well, not so boring..

When you have some spare time:
About pebbles, I purchased sacks from white and grey pebbles in SD. Is it possible to find other colours in DR? (blue, red yellow). Everybody told me NO. Is it possible to buy them sorted in size? (the ones I purchased were totally random).

About lime, I purchased some in El Pomiel and at el 12 de Haina. But I wonder if they didn't sell me ground CaCO3, unless it was a lime with a 100 years curing time.. I asked for instructions for preparing mortar, but nobody was able to answer me. I also went in San Cristobal, road to Palenque, where there is this village where they prepare lime in their own tires-fired "ovens' . But so much "uncooked" stone in the lime, and quite expensive. The purpose was preparing mortar for stone wall and rendering. Any advice?

About sand: are there any companies selling white/yellowish sand, with size specifications? when I go in a ferreteria in Sd they have this red sand, "para mezcla o para empanete?".

About limestone:
- Is it used somewhere for wall building? Dimension or rubles?
- Is it possible to buy blocks in a quarry? (to have them plug and feather cut). Approx USD/m3?

About clay:
Do you know where the factory (in Bonao?) that sells kaolinitic clay they use in the ceramics oven on the Autopista Duarte for fireproof bricks?

Sorry to be so curious, but when I am in RD I have so many difficulties finding reliable info, so any info you can provide would be most welcome.

Barnab?

Dominican cement companies import most of their clinker from South America (Colombia and Brazil are the main suppliers).
- Tordok

You forgot Venezuela...........

Sorry to anyone interested in Nicolas's and Susie's post...I sent them direct email. I don't want any of my answers to start sounding like a solicitation of business in this forum (which they are not).

Heck, that was interesting!

Hardly boring. F-1 racing, that is boring. Geology and such is very interesting.

I wish you had posted those e-mails, since that is extremely valuable information for all the people that are planning on building here.

Dave that was a terrific bit of posting. I know that site in Navarrete very well....as well as the "hole" on the right just as you pass the Asphalt site on the way to Santiago....good place to dump a few PRD bodies, I'd say...humm..


HB

Another thing people forget in concrete......

"If I remember correctly, just another gallon or so of water when mixing the cement will decrease the strength of the cement by more than 50%."

The mixing process is terribly critical when looking for strength...and your points are right on the mark. There is truly no way to make a great concrete mix "on the ground in mounds" as you describe. Yet, this is the principle traditional method for a lot of the construction in the DR and is done every day here and other areas of the world too. As the song goes, " it was good enough for grandpa, it was good enough for grandma, it was good enough for daddy so its good enough for me........" (or something like that...haha).

Another thing that is missed in the DR is curing time. Concrete needs to stand and cure for # 's of hours before you can begin "stressing it". The amount of time depends on the mix and the application. While curing, you really want to keep water on the concrete so it does not dry out too quickly and weaken (at least in the initial stages). That may be another one of the reasons DR construction workers add too much water to the mix initially....they see it drying/absorbing quickly (cement LOVES water) and believe more is better (when they should actually form the concrete in a proper mix and then actually misten the product as it is curing).

All I can say is that due to the bad mixing technique of the island, I am grateful that so much rebar is used in structures in the DR or there would be WAY MORE damage when these earthquakes have hit.

Prices of Cement

What are the prices of cement and other construction materials in the DR? And how would you compare these produce in respect to price with Cuba?
My family are looking to import Construction Materials into Turks and Caicos and we are in the process of shopping for Prices of Cement and other aggregate.
8 inch concrete block sell for $1.69 each. When you factor in the bulk purchase price, transportation and all taxes, does it appear that DR have better Prices than Cuba.
This is a business that I know absolutely anything about, however, being a shareholder in the newly formed company I would like to see where my interest lies.

All answers and information in the thread would prove to be healthy

Kind regards


TCIDR

I know a bit about shipping materials to the T&C

....do you have a tug and barge for raw materials? How about some type of "closed vessel" for cement? Do you already have your sales people in the islands (T&C , Inagua, Exumas, etc.) once you get your materials there? Cuba has cheaper materials (cement and gravel) but they are not as good from a quality standpoint (not ASTM) ...but they still have their market in the islands.

Dominican cement is the highest priced in the Caribbean (almost in the world)....there is a real pricing problem here in DR.

Bulk construction materials....I am sure you have the equipment to load and unload your boats ...and please make certain to not forget about potential demurrage at the ports AND the export permits from the environmental department of the DR. I speak from everyday real life export experience on this topic.

Suerte!

Daily rate dor a concrete mixer: 2000?
Daily wage for 1 ayudante: 300,400?

Many people prefer to pay 2 or 3 ayudantes. Why are they so many cracks on the walls, and not only in the barrios?.. Once on a construction I was doing I proposed the workers to rent a mixer for one week as we had a lot of rendering to do, no sir thanks.

On the same site we had to pour a 600 sqm flat roof over 20ft columns. I wanted to rent steel forms. No problem. I asked the company if they could supply people to have the forms installed. No Sir. Do you know of any people that can do that? No Sir. I asked my "maestro" if his guys could handle with that. No Sir. I had to go with wooden forms. Heavy work rendering after that..

It is quite strange how in DR you can -at least in popular areas - build about anything you want to. But if you yo go out of the simple "block and cement" lane, you get lost quickly because it is so difficult to find reliable info and workers.

I think that's why many people prefer to pay overpriced houses than build themselves.

Barnab?