Posts Tagged ‘concrete’

Concrete is gray, not green, right?  Well, there are many ways that concrete is becoming much more environmentally friendly.  The green movement is a great way to better our current products and spawn innovation for new creations.  As these new, more efficient products gain speed and drop to a reasonable price, people will be much more motivated to upgrade to sustainable materials and replace the old, less efficient products.  This can be seen when comparing the cost to light a room, or heat your water.  However, there is a great misunderstanding about the use of concrete and how it affects our communities and natural resources.  The progress of concrete mix designs is not a hot topic at the dinner table or on the evening news, so it often gets ignored or overlooked by the masses.

Let’s begin with the basics: Water, Rock, Sand and Cement.

Water is used for the hydration process – how everything binds together.  The water needs to be good clean water, but does not need to be potable (drinkable) according to the Portland Cement Association.  Thus, this ingredient requires no additional purification or processing to be used.  After the hydration process is complete, the majority of the water will evaporate or return to the groundwater system, making it a completely renewable source.

Rock found in concrete can come from anywhere.  That means that it can come from down the road and be locally provided.  It is true that some rock has a greater compression strength than others, but many states require local materials be used for government jobs.  The local use reduces excess transportation costs and saves other resources, making it a favorite material for LEED certified buildings.  Recycled materials such as blast furnace slag and reused glass are making a steady appearance in both the construction industry and the art world.

Sand is even easier to come by and is not only dirt cheap and plentiful, but also is often a local mineral and highly favored for all projects.  Rock and sand make up about 70% of concrete mix and can be a very good choice for earth friendly construction because they are naturally occurring materials and require little to no processing.  The main energy consumption comes into play when they need to be transported great distances, which was already discussed.

Cement does require a fair amount of energy to process.  That is one reason other sources of cementitious material is becoming more popular.  Fly ash, for example has similar properties as portland cement, but is a by-product of power plants and is therefore a reused material.  There are many other materials that are making their way into concrete that are less energy intensive to refine into a usable bonding agent.  Some of these materials include naturally occurring pozzolans, microsilica, fly ash, and other proprietary ‘crete products.

I foresee a continual change in the actual mineral recipe of the cementitious materials used in concrete in the future.  Along those lines, I don’t see any lack of demand for this diverse and beneficial construction material in the next decade or century.  Concrete will be used in the future just as we currently use the dirt, timber and steel of the past.  As we continue to make improvements in our products, we will be able to save money and reduce our impact on the worlds resources.

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I began my walnut and glass concrete coffee table a while back and am really looking forward to completing it.  I have been occupied with the design of a concrete patio for a client and hope to make some progress this week.  So for now, the coffee table sits in my carport awaiting the finishing touches.  This table has some great features and want to mention a few of them here even though they will be repeated when I create a separate page for it.

Starting on the outside, it has a dark walnut border that very nice hardwood.  I bought it specifically for this project and I think it really sets the table apart from some of my other work.

Moving inward, the concrete was colored with a light walnut pigment, so the color is throughout the material.  When I placed the concrete in the form, I was afraid that it was a bit on the pink side, but after the concrete cured, that is no longer a concern.  It is not that I have something against pink – I’ll make you a hot pink table if you like, but not with the dark natural look of the walnut wood.

Then there is another walnut frame that holds up the inner piece of glass.  The inside wood frame was cut from the same board of wood, so there is very good consistency.  The glass is about 9″x29.5″ and not only adds detail to the piece, but can also be used to add your own art under the glass.

The entire table weighs in at about 45lbs, which is remarkably light for a 42″x21″ concrete coffee table.  The top sits about 18″ tall and will be urethane coated when finished.  Each leg is gusseted and the concrete is reinforced with steel channel.

So even with all of the description above, I don’t think that I have painted a very good picture of how this table is turning out.  I just have to finish it and post some pictures.   They will be coming soon.

Update:  The Walnut and Glass Coffee Table was finished last night.  Check out it’s page.

When I first placed my diploma in a concrete frame, I worried about any accelerated deterioration.  Since then, I have really tried to research the variables that will help preserve documents, art, and anything else someone may place in a concrete frame. There are a number of factors that will cause your pictures to fade, wear, or deteriorate prematurely.  I wish to discuss some of these factors and provide basic suggestions.

Humidity is the biggest threat to photos and documents.  The Library of Congress states that environments over 60% relative humidity will accelerate deterioration.  It is recommended that photos be stored at 30%-40% RH.  Less humidity is better for long-term storage, but when you consider that very low humidity can also cause skin irritation, difficulty breathing and increased static electricity, it is best to find a happy middle ground.  According to the weather channel, the appropriate range of indoor humidity is between 30%-50%.  Controlling the humidity will keep your photos, and everything else, from mildew, rot and premature decay.

Temperature also affects the lifespan of photos.  The Library of Congress suggests that around 68 degrees is best for around the house.  Colder is better, but no one wants to wear a down jacket inside.  Heat is particularly tough on color prints and causes fading and loss of photo contrast.   Again, there needs to be a balance between photo and human comfort.

Ultra-violet light will sap the life out of photos as well.  UV light will cause photos to become brittle and prone to being damaged easily.  Colors can fade and yellow in the presence of these light rays for a prolonged period of time.  To avoid this, photos can be placed out of sunlight, under safe lighting source, and behind UV filtering glass.  Any one of these remedies could keep your artwork around for future generations.

Acidic environments (pH less than 7) also cause harm to pictures.  This is what I first thought about with my concrete frame.  Concrete is inherently alkaline (pH greater than 7).  That is why it can protect embedded bare steel from rusting for centuries.  This acid-free characteristic makes concrete ideal for storing or displaying photos.

Concrete picture frames, side tables, coffee tables and countertops have a broad range of colors and finishes.  The natural look of gray concrete appeals to some, while colorful, embedded and shiny colors appeals to others.  I have had a recent order for picture frames that have no finish and I have been reminded of how I like the simple, strong look.  I suppose that this plain look could highlight the artwork found within the frame.

On the other hand, I can’t stop trying out different ideas and colors.  A future project (not sure if it will be a frame or table or something new) will use blue rocks and colored matrix.  I want to make this project very vivid in color and be a creative piece of art.  I like the ground look which displays the rock.  My wife likes the clean, solid look.

Unfortunately, when you talk about concrete with others, they visualize old, grotesque industrial buildings.  As a structural engineer, I must boast that those buildings have probably outlasted anyone’s expectations and served their purpose well, but not many want to hang that old look on their wall or eat your popcorn from its pitted top.  In reality, concrete can be as refined as marble and as colorful as any paint selection.  I just like working with this very diverse material.

I was daydreaming about some of the frames, tables, chairs and so on that I had floating in my mind.  Concrete can be anything.  Obviously work was a little slow, so my focus kind of wandered into other crazy ideas for concrete furniture.

A while back, I checked out videos about logging and how to properly fell a tree because I was about to drop a tree at my co-workers place between two houses and an array of other obstacles.  If you have a few minutes, check out the youtube video about California Redwood logging back in 1947.  I was very impressed.  National Geographic recently claimed that the Redwood forest has actually been expanding for the first time in a century – that is even more impressive.

Anyway, it got me thinking about how well concrete and wood go together.  All through my college education I was taught that concrete and steel were the match made in heaven.  I must agree, but the combination of wood and concrete can be combined in a similar way.  The wood should have a tensile strength of about 600psi and good development due to the porosity and concrete bonding.

I will have to play around some more with concrete & wood designs and look into how to dry and mill some timber.  If you have any experience or suggestions here, please let them be known.

Update:  I have really enjoyed working with wood in my furniture projects.  I have come up with a lot more ideas and only wish that I had more time and resources to make them come alive.  They will.

Hey, I am glad you found me. Frankly, I am a little surprised, but while you are here check out my concrete picture frames and concrete tables.

I sell concrete art in person, checks, paypal, Etsy, even for a barrel of sunflower seeds – whichever method you prefer.  All of my crazy creations come out of my tiny shop in Savannah Georgia and I have shipped items as far away as Hawaii.

If you would like something custom made or have ANY question about concrete furniture, feel free to contact me:

Dan Miller
concretepicture@gmail.com
912-713-5226
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