This article was submitted by Akansha.

Micro silica has been one of the world’s most widely used products for concrete for over eighty years. Its properties allowed high compressive strength concretes; water and chemical resistant concretes, and they have been part of many concrete buildings that we see nowadays. Its disadvantage, though, has been its relatively high cost and contamination, which affects the environment and the operators’ health. As micro silica, as a powder, is thousand fold thinner than cigarette smoke. Operators must take special precautions to avoid inhaling micro silica and not to acquire silicosis, an irreversible disease.

In the middle of 2003, a product which could replace micro silica seen the contaminant effects, having the same or better characteristics and at a reasonable cost was on the design table. The goal: silica fulfilling the environ-mental regulation: ISO-14001.

Using tools from physics, chemistry and recent nanotechnology advances, the challenge was fulfilled.Lab tests and production tests proved that the nano silica did not contaminate (because its state), but it also produced better results than micro silica, and a litre bottle of the product was equivalent to a barrel full of micro silica, extra cement and super plasticizing additives.

Because of its innovation the nano silica was tested for over a year in the world’s largest subterranean copper mine to prove its long term characteristics. Cuore concrete takes care of the environment, the concrete and the operators´ health. It is the first nano product that replaced the micro silica.Cuore concrete surpassed the expectations of its design and gave concrete not only the high initial and final resistance but in addition, plasticity, impermeability, minor final cost of work, and cement savings of up to 40%. Also, it lowered the levels of environmental contamination.

In addition, a liter bottle of Cuore concrete equals a whole barrel of micro silica, extra cement and super plasticizers. If before a 2 meters thick beam was required to hold a bridge correctly, now only 75 cm are required. If before 28 days were necessary in order to achieve compressive strengths of 80MPa, now only 1 day is required. The pre stressed beams that before required 3 days to be ready and needed to be cured with water and steam , now require only 1 day and they do not need water.

Moreover, Cuore concrete became one of the first indicators of the properties that the next commercial nano cements in the market will have: nano particles of silica turn into nano particles of cement (nano cement) in the chemical reactions that take place in the concoction of the concrete, Thanks to all these advantages, the entrance of nano silica Cuore concrete into the market modified the concept of what is possible and what is not in the concrete field.

Since 2004, the greatest copper underground mine of the world, has been using nano silica concrete and the use of the micro silica in this deposit has been prohibited.

Properties of concrete with Cuore concrete nanosilica

• In high compressive strengths concretes (H-70), Cuore concrete is 88% more efficient than micro silica, added to concrete and super plasticizers. ( For an average 9,43 Kg. of Cuore concrete Nanosilica, 73Kg. of all the others additives are used).

• The production cost of is drastically lower than using the traditional production method or formulas.

• It has an air inclusion of 0% to 1%

• The cone test shows that It preserves the cone shape for more than one hour. (with a relation of H2O/Cement=0.5, adding 0.5% of Nano silica of the metric volume of the cement used, it conserved a its circle shape of 60 cm for two hours, with a lost of only 5%). The nano silica has a plasticity that has been compared to the policarboxilate technology. Therefore the use of super plasticizing additives is unnecessary.

• High workability with reduced water/concrete levels, for example: 0,2.

• Easy homogenization. The reduction of mixing times allows concrete plants to increase their production

• Depending on the cement and the formulations used for concrete (tests from value H-30 to H-70), shows that the material provides compressive strengths between 15 MPa and 75 MPa at 1 day; 40 MPa and 90 MPa at 28 days and 48 MPa and 120 MPa at 120 days.

• Nano silica fully complies with ISO 14001 regulations regarding the environment and health. It preserves operators of the danger of being contaminated with silicosis and does not contaminate the environment.

It successfully passed all the tests and since the beginning of this year it is being commercialized in different parts of the world.

Immediate benefits for the user

1) Cessation of contamination caused by micro silica solid particles.

2) Lower cost per building site.

3) Concrete with high initial and final compressive and tensile strengths.

4) Concrete with good workability.

5) Cessation of super plasticizing utilization.

6) Cessation of silicosis risk.

7) High impermeability.

8 ) Reduction of cement using Cuore concrete Nanosilice

9) Cuore concrete nano sílica on itself produces nano cement.

10) During the moisturizing reaction of the cement, the silica produces CSH particles, the “glue” of the concrete ensuring the cohesion of all the particles.

11) Cuore concrete has a specific surface near to 1,000m2/gr (micro silica has only 20m2/gr) and a particle size of 5nm to 250 nm.

As a consequence of its size, Cuore concrete produces nano cristals of CSH, filling up all the micro pores and micro spaces which where left empty in traditional concrete production.
Former described function reinforces the concrete structure on levels, thousand times smaller then in the case of traditional concrete production. This allows the reduction of the cement used and gives the compression needed to reduce over 90 % of the additives used in the production of H-70 concrete.

Cuore concrete allows to save in between 35% and 50% of the used cement.We do stress that we recommend to change the formula of the concrete in order to take advantage of the characteristics of the Cuore concrete Nano silica particle.

Less material is needed to obtain better results, using Cuore concrete.

The results are the proof.

1) Resistance to compression from 40 to 90MPa in 1 day.

2) Resistance to compression from 70 a 100 MPa (or more) in 28 days.

3) Versatile: produces high resistance even with low addition (1 to 1,5 % of the cements weight) and gives self compacting characteristics with higher proportions (2,5 %).

4) Meets the norms of environmental protection (ISO14001).

5) 70% less use of additives as traditional silica, super plasticizers or traditional fibres.

6) Equal or minor raw material cost as in traditional ??production with super plasticizers, and or fibres.

This useful information is submitted to us by : Pascal Maes

The result: The water-circulation system serves as a giant radiator in the winter and cooling system in the summer. It has no boilers to supply heat, no electric air conditioners to supply cool. The apartments also feature gray-water recycling — a process that’s just starting to catch on in Beijing in much smaller buildings — to filter waste water from kitchen sinks and wash basins back into toilets.

2) Dongtan Eco City, Dongtan
Developed by the Shanghai Industrial investment Corp., Dongtan Eco City , roughly the size of Manhattan , will be the world’s first fully sustainable cosmopolis when completed in 2040. Like Manhattan , it’s situated on an island — the third-largest in China . Located on the Yangtze River, Dongtan is within close proximity of the bustle of Shanghai .

By the time the Shanghai Expo trade fair opens in 2010, the city’s first phase should be completed, and 50,000 residents will call Dongtan home-sweet-sustainable-home. The goals to be accomplished in the next five years: systems for water purification, waste management, and renewable energy. An infrastructure of roads will connect the former agricultural land with Shanghai .

3) Olympic Stadium, Beijing
Sports stadiums have long followed the enduring design of one of the original wonders of the world, Rome ’s Coliseum. Herzog & de Meuron’s National Stadium in Beijing is an attempt to rethink the classic sports-arena layout for more ecologically correct times.

The Swiss architects (of Tate Modern fame) wanted to provide natural ventilation for the 91,000-seat structure — perhaps the largest “eco-friendly” sports stadium designed to date. To achieve this, they set out to create a building that could function without a strictly enclosed shell, yet also provide constant shelter for the audience and athletes alike.

To solve these design problems, they looked to nature for inspiration. The stadium’s outer grid resembles a bird’s nest constructed of delicately placed branches and twigs. Each discrete space within the facility, from restrooms to restaurants, is constructed as an independent unit within the outer lattice — making it possible to encase the entire complex with an open grid that allows for natural air circulation. The architects also incorporated a layer of translucent membrane to fill any gaps in the lacy exterior.
image � Herzog and de Meuron

4) Donghai Bridge , Shanghai/Yangshan Island
A key phase in the development of the world’s largest deep-sea port was completed when China ’s first cross-sea bridge — the 20-mile, six-lane Donghai Bridge — was officially opened in December, 2005. Stretching across the East China Sea , the graceful cable-stay structure connects Shanghai to Yangshan Island, set to become China ’s first free-trade port (and the world’s largest container port) upon its completion in 2010.

To provide a safer driving route in the typhoons and high waves known to hit the region, Donghai Bridge is designed in an S-shape. The structure, reported by Shanghai Daily to have cost $1.2 billion, will hold its title of China’s — and one of the world’s — longest over-sea bridge for only a couple of years, though. In 2008, the nearby 22-mile Hangzhou Bay Transoceanic Bridge, which also begins (or ends, depending on your journey) in Shanghai , will earn the superlative.
Photo: Getty Images

5) National Grand Theater, Beijing
Located near Tiananmen Square , the 490,485-square-foot glass-and-titanium National Grand Theater, scheduled to open in 2008, seems to float above a man-made lake. Intended to stand out amid the Chinese capital’s bustling streets and ancient buildings, the structure has garnered criticism among Bejing’s citizens for clashing with classic landmarks like the Monument to the People’s Heroes (dedicated to revolutionary martyrs), the vast home of the National People’s Congress, or Tiananmen Gate itself (the Gate of Heavenly Peace).

French architect Paul Andreu is no stranger to controversy — or to innovative forms. A generation ago, in 1974, his untraditional design for Terminal 1 of Paris ’s Charles de Gaulle airport was criticized for its unusual curves, yet Andreu’s groundbreaking, futuristic building later was seen to distinguish de Gaulle from more generic European and international air hubs. (The same airport’s Terminal 2E, also designed by Andreu, gained attention in 2004 when it collapsed, tragically killing four people.)

Beijing ’s daring National Grand Theater is as much a spectacle as the productions that will be staged inside in the 2,416-seat opera house, the 2,017-seat concert hall, and the 1,040-seat theater. At night, the semi-transparent skin will give passersby a glimpse at the performance inside one of three auditoriums, a feature that highlights the building’s public nature.

The Commune is now operated as a boutique hotel by the Germany luxury hotel group Kempinski, which is responsible for an upcoming expansion, which will feature 21 homes (including replications of the originals). One element will remain untouched in the new development: the Commune’s private pedestrian trails, which trace untouched sections of the Great Wall.
Photo: Ma Xiaochun

2. Beijing International Airport , Beijing
According to the U.S. Embassy to China, the country will be building 108 new airports between 2004 and 2009 — including what will be the world’s largest: the Beijing International Airport, designed by Foster & Partners. Set to open at the end of 2007, in time for the Beijing Olympics in 2008, the airport terminal will cover more than 1 million square meters, giving it a bigger footprint than the Pentagon.

It’s designed to handle 43 million passengers a year initially and 55 million by 2015, figures that will probably push the new facility into the ranks of the top 10 busiest airports, going by the 2004 numbers from the Airports Council International. Given the scale and traffic, Foster & Partners focused on the traveler’s experience, making sure that walking distances are short, for instance.

Building on Foster’s experience designing Hong Kong ’s new mega-airport, the massive Chek Lap Kok, the sprawling Beijing terminal is housed under a single roof. To help passengers distinguish between different sections of the vast space, skylights cast different shades of yellow and red light across walls — a subtle but innovative navigational aid. The architects also kept sustainability in mind: An environmental-control system reduces carbon emissions, and skylights situated on a south-east axis lessen solar heat, keeping the building cool.

3) Shanghai World Financial Center, Shanghai
Rising in the Lujiazhui financial district in Pudong, the Shanghai World Financial Center is a tower among towers. The elegant 101-story skyscraper will be (for a moment, at least) the world’s tallest when completed in early 2008.

One of the biggest challenges of building tall is creating a structure that can withstand high winds. The architects devised an innovation solution to alleviate wind pressure by adding a rectangular cut-out at the building’s apex. Not only does the open area help reduce the building’s sway but it also will be home to the world’s highest outdoor observation deck — a 100th-floor vista that will take vertigo to new heights.

4. National Swimming Center , Beijing
The striking exterior of the National Swimming Center , being constructed for the 2008 Olympic Games and nicknamed, the “Water Cube,” is made from panels of a lightweight form of Teflon that transforms the building into an energy-efficient greenhouse-like environment. Solar energy will also be used to heat the swimming pools, which are designed to reuse double-filtered, backwashed pool water that’s usually dumped as waste.

Excess rainwater will also be collected and stored in subterranean tanks and used to fill the pools. The complex engineering system of curvy steel frames that form the structure of the bubble-like skin are based on research into the structural properties of soap bubbles by two physicists at Dublin ’s Trinity College . The unique structure is designed to help the building withstand nearly any seismic disruptions.

5) Central Chinese Television CCTV, Beijing
The design of the new Central Chinese Television (CCTV) headquarters defies the popular conception of a skyscraper — and it broke Beijing’s building codes and required approval by a special review panel. The standard systems for engineering gravity and lateral loads in buildings didn’t apply to the CCTV building, which is formed by two leaning towers, each bent 90 degrees at the top and bottom to form a continuous loop.

The engineer’s solution is to create a structural “tube” of diagonal supports. The irregular pattern of this “diagrid” system reflects the distribution of forces across the tube’s surface. Designed by Rem Koolhaas and Ole Scheeren and engineered by Ove Arup, the new CCTV tower rethinks what a skyscraper can be.

This is submitted by Er. Akhansha

1) Chichen Itza in Yuvata, Mexico

2) Christ the Redeemer in Rio de Janeiro, Brazil

3) Colosseum in Rome, Italy

4) Great Wall of China

5) Machu Picchu in Cuzco, Perú

6) Petra in Jordan

7) Taj Mahal in Agra, India

Great Pyramid of Giza in Cairo, Egypt has honorary status as it the  last remaining ancient wonder of the world