Posts Tagged ‘cement’

Building Blocks for Better Buildings

Wednesday, October 1st, 2008

The great mosque of Djenne looms over one of the larger marketplaces in Mali, Africa. On the flat brown flood planes, mud walls up to 24 inches thick bear the weight of what looks like a giant sand castle. Protruding from the structure are carefully placed wooden poles and ostrich eggs adorn the tips of the spires at the mosque entrance.

A mosque has stood in the spot since the 13th century. This is quite a feat since the incredible structure is made from nothing more than sun-baked mud bricks and mud. The original mud used for the mosque fell to the ground centuries ago and the current structure has stood in its place since 1906, but the size and overall strength of the building proves that the right mixture of sand, water, straw and gravel has immense potential as a building material.

Integrity Block has developed a modern version of the ancient mudbrick that is perfect for today’s architectural and landscape design. The company specializes in manufacturing green building alternatives and, as proudly stated on their website, “has developed the first green replacement for concrete blocks.”

The Great Mosque of Djenné, Mali, is the
largest mud brick building in the world.

Designing a brick takes more than just throwing a few ingredients together. It took the company two years of research and development before finding the perfect balance which allowed for easy production, and structural integrity.

Unlike the bricks used in mud huts and mosques that need annual replacement or patching up, the Integrity Block has the same strength and durability of cement.

Not only that, but the blocks are in fact a step up from the cement blocks: They are much easier to produce than traditional bricks, requiring less than half the energy of concrete production. It is also made up of 50% pre-recycled content and can generate LEED credits. The LEED (standing for Leadership in Energy and Environmental Design) system, rates buildings at a variety of levels depending on their environmental performance. The higher a building’s rating, the easier a building is to lease or sell since this also implies that the building uses less energy for such tasks as heating, cooling and lighting. More information on specific LEED credits here.

Integrity Blocks improve a home’s temperature regulations, for example, by storing heat during the day (keeping the indoors cool) and releasing the stored heat at night. They are also excellent barriers against outdoor noise.

Sometimes it’s good to go back to the basics.

Tags: , , , , , , , ,
Posted in Buildings | 1 Comment »

Streets for Solar

Tuesday, August 19th, 2008

Steam rises from the never-ending stretch of road ahead. What looks like water rolling over the street, is just heat escaping. Walking on the blacktop barefoot would leave anyone but a fire-walker grunting in pain.

Our planet is covered with a web of streets and this cement absorbs and stores an abundance of the sun’s energy. Researchers at the Worcester Polytechnic Institute (WPI), are looking into ways of using this heat as yet another renewable energy source. They have already developed solar collectors that would transfer the energy into electricity.

The ball started rolling with the president of Novotech Inc., Michael Hulen, who funded the research project meant to prove the efficiency of Novotech’s patented heat absorbing design. Based in Acton, Massachusetts, Novotech is one of the biggest suppliers of infrared optical and semiconductor materials.

WPI’s research was presented at the Annual Symposium of the International Society for Asphalt Pavements August 18-20, in Zurich, but like most things in life, the presentations are not accessible for free so I have no information about WPI’s results as of yet. (In addition to the topic of ‘roads for energy production’, other areas of interest such as noise reduction, recycling, drainage and environmentally friendly maintinence on pavements were also discussed at the event.)

The idea of using already existing streets as solar panels is a promising one; Roads are reworked every few years and the technology can be incorporated when repaving is necessary. Not only that, but the unfortunate truth is that roads, parking lots and sidewalks are more common than anything else in many areas. With Novotech’s design, at least these concrete landmasses can be retrofitted as solar power generators.

The heat collectors would be located a few centimeters underneath the pavement, not changing the outward appearance. Cars will roll along on the roads, as usual, but now power will be generated right underneath the tires.

For more information, check out an in depth article at Science Daily.

Tags: , , , , , , , , ,
Posted in Buildings, CleanTech, Electricity, Energy, Solar Thermal | No Comments »

Hycrete-Cementing Building Technology

Thursday, June 5th, 2008

When it comes to improvements, it is good to start with the basics. The fundamental part of any city, road, or building is concrete. By reducing the amount of energy needed to build, and by simplifying the components of the concrete, CO2 emissions are reduced while the whole building process is made more efficient.

Voted a GoingGreen winner and covered in numerous publications ranging from Time Magazine to Gizmag, Hycrete is a company at the forefront of cement technology. Hycrete has been manufacturing products in New Jersey for 40 years, and had already made a significant impact to the building industry by bringing a class of rust inhibitors to the market in the 1950s. Its more recent claim to fame-waterproof cement technology-was developed in the mid 90s when Michael S. Rhodes, one of Hycrete’s key inventors, developed the unique moisture and corrosion blocker.

Rhodes’ accomplishments are impressive: He has worked with NASA to develop solid rocket fuels and improve the heat shield of the Apollo series.  The inventors’ interests are varied, however, and don’t stop there: Rhodes was also involved in creating products for the military, such as protective foams for submarines. At Hycrete, it was time to develop a product to shield one of the most used building materials on earth-Cement-from the elements.

The main problems associated with cement are corrosion and cracking. Hycrete describes the issue in their data sheet: “Conventional concrete absorbs water and dissolved salts through a network of capillaries and cracks. [This water weakens the cement and may cause rusting to any steel piping or internal structures. Also, water runoff is often an issue] Hycrete Elite’s hydrophobic properties shut down the capillary wicking action that carries salts to the reinforcement layer and transforms concrete into a waterproof construction material. Unlike external membranes or coatings, Hycrete Elite provides real time protection as it is mixed into concrete to provide integral waterproofing and corrosion resistance.”  Being waterproof, cement mixed with hycrete elite is perfect for rooftop gardens, parking lots, erosion control etc.

Waterproofing cement the ‘old-fashioned’ way is a major environmental issue: A popular approach is to line the entire structure with a waterproof membrane. The problem with this membrane is that it is typically composed of volatile organic compounds (VOCs) which are non recyclable, so when this cement needs replacing it is simply tossed into a landfill. Almost half of the building materials sitting in landfills are made up of this kind of cement. 

The soap like properties of hycrete, on the other hand, follow the ‘cradle to cradle’  philosophy and break down when returned to the soil. By being mixed into the cement rather than sprayed on top of it (though this is an option with other hycrete waterproofing products), the cement is recyclable and can be reused.  It would be nice not to have to worry about leaky roofs while watering your fruit garden on top of a high rise complex.

Tags: , , , , , ,
Posted in Buildings | 1 Comment »