Some 2,000 years after they were first erected, Ancient Roman harbors made from concrete are still standing across Europe. Meanwhile, more modern constructions have proved far less durable. Finally, scientists have solved the puzzle of what made the ancient concrete so strong — and they think the discovery could make modern buildings more environmentally friendly. The results are published in American Mineralogist. Concrete used for ancient sea walls was made by mixing lime, seawater, volcanic ash and rock. Researchers have now discovered that elements in the ash react with sea water, which actually strengthens the material. Researchers discovered the Roman concrete contained aluminium tobermorite, a rare mineral that adds extra strength. When the Roman concrete was exposed to seawater, the tobermorite crystallised and spread. The researchers said that long-term exposure to sea water helped these crystals to continue growing, reinforcing the concrete and preventing cracks from developing.

If centuries ago famous architect Antonio Gaudi heard that his masterpiece Sagrada Familia construction will be completed with 3D printers, he would be surprised. However, 3D printers are successfully implemented in construction processes. For example, Emerging Objects Company created 3D printed ceramic cool bricks, Chinese company WinSun 3D printed a five-story apartment building and a 110 square meters villa , American architect Adam Kushner plans to build the newest 3D-printed estate . World's first 3D printed home constructed in Amsterdam Today the innovative Dutch construction company Heijmans has unveiled their latest avant-garde project: a 3D-printed steel bridge in the heart of Amsterdam. A new bridge created in collaboration with Dutch startup MX3D and designed by Dutch designer Joris Laarman. Multi-axis industrial robots will construct the pedestrian bridge using cost-effective and scalable technologies. MX3D equips multi-axis industrial robots with 3D printing tools and develops software so that the robots print metals, plastics and combinations of materials in virtually any format. From large construction to small part - with this technique MX3D can 3D print strong, complex structures of durable material. The new technique is cost-effective and scalable, more than current 3D printing methods, and offers creative robot production solutions for art, construction and more. The goal behind the experimental 3D-printing project is the eventual creation of an automatic construction site. According to Jan van de Ven, Heijmans' Manager of Business Development, the use of 3D printing for construction purposes also has benefits in the design sector and, once popularized, can revolutionize the way we approach the design/build process. "Construction and design are currently rather separate factors in construction - the architect design something and the constructor interprets the design and builds what he thinks is needed. But using 3D printing for a bridge makes design and construction operate hand-in-hand. For instance, both activities are done at the same time, instead of first building the structure and then adding the design later. This means we will also have to start looking at design in a completely different manner." The location of the bridge has not yet been determined but will be announced soon. The pedestrian bridge will span one of Amsterdam's old canals and has been described by designer Joris Laarman as a "fantastic metaphor for connecting the technology of the future with the city's historic past, in a way which would reveal the best aspects of both worlds." From September 2015 a visitor center opens for the public, where the progress of the project can be followed. MX3D and the City of Amsterdam will announce the exact location of the bridge soon.

Nasa is holding a competition with US$ 2.25 million in prizes to find the best sustainable habitat that can house astronauts on deep space exploration missions. The US space agency is challenging designers, architects, engineers and 3D printing enthusiasts to not just build sustainable housing that can be quickly 3D printed and replicated, but also to make sure that the materials used are both recyclable and indigenous to Mars. The new project will feature two different stages. The first stage, which is currently open for registration, requires entrants to design an architectural concept for a habitat that makes use of 3D printing, with 30 submissions shortlisted and a cash prize of US$ 50,000 to be given out. The second stage of the competition opens for registration on 26 September and entrants can choose to enter either or both of the two challenges set, which each carry a prize of US$ 1.1 million. The Structural Member Competition (Level 1) requires entrants to develop the fabrication technologies needed to manufacture structural components either from a combination of indigenous materials and recyclables, or indigenous materials alone. Meanwhile, the On-Site Habitat Competition (Level 2) challenges competitors to build full-scale habitats using indigenous materials or indigenous materials combined with recyclables.

It's traditionally played on grass and clay, but could tennis matches one day take place in a waterproof bubble in an "underwater Wimbledon"? An architect Krysztof Kotala from Polish firm 8+8 Concept Studios has released designs for an ambitious project to build an underwater tennis court off the coast of Dubai. He showcased some computer-generated images of the proposed tennis court. An underwater tennis complex could be built just offshore in the Persian Gulf, between the Burj al Arab and the Palm Jumeirah islands. Part sports arena and part aquarium, the eccentric concept for the seven-court complex calls for a rooftop coral reef, which would bring an abundance of sea life to the area for spectators (and players) to view. During his interview to Arabian Business Kotala told that the idea had strong commercial potential and would combine the best of "technology, ecology and sport." An architect is currently seeking investment from local backers to make the concept a reality. "There is not an investor but I would like to get interest as I think it is a good idea," he told Arabian Business. However, although the underwater sports concept looks stunning, engineers have poured water (excuse the pun) on the idea that such a tennis court could be built with current technology. Sarah Fray, director of engineering and technical services at the Institution of Structural Engineers in London, explained that one of the biggest challenges would be to create the large span of glass to cover the court. This would have to be at least 33 meters wide to accommodate the court and spectators. Currently, flat panels of glass can be manufactured in single pieces around 10 meters long - such as panels used in Apple's store in Turkey - but new machinery would have to be invented to make larger panes of curved glass, the type of which would be needed for the design. Another challenge is how to get to the tennis court. She explains that there would have to be a way for the structure to be connected to the surface. However, she conceded that the arched shape of the underwater court is a good idea because it's the best way of resisting pressure, the likes of which would be vast, particularly if the court was submerged at a decent depth beneath the waves. Will Stewart, a Fellow of the Institution of Engineering and Technology (IET) added that the design may not appear as bright inside as the concept images suggest. He explained the glass would have to be many meters thicker at the edges than at the center of the arch, so views of the ocean would not be as bright as they are in the concept pictures. Dubai is no stranger to unusual tennis courts. In 2005, a court was built atop the 305 meters tall Burj al Arab hotel to promote the Dubai Tennis Championships. Besides this Dubai is known for outlandish construction projects including man-made islands and the world's tallest building. It also already has a restaurant - Al Mahara - that's underwater. However the technological challenges are big, but the human challenges are bigger. And in future everything is possible.

Last year architect Adam Kushner announced plans to build the newest 3D-printed estate in Gardiner, New York. Recently, the architect and CEO of D-Shape, James Wolff, presented new renderings of Kushner's project at 3D Print Week NY that show an even more over-the-top plan than we even imagined. According to the project details, the entire structure will be built using a modified version of Enrico Dini's oversized D-Shape printer. And we're not just talking one basic house here. No, Kushner is determined to build a massive swimming pool, pool house and car port to go along with the four-bedroom, 223 square meters home, and eventually creating one enormous 3D-printed estate. Although still in the planning stages, the residence is slated to be built about 137 kilometers from New York City on a 20 thousand square meters parcel of land that Kushner and his wife purchased three years ago. Kushner explained that it was the plot's naturally rocky landscape that inspired the ambitious 3D design. "The materials on the site will be used to form the pieces of the site, which reflect the very characteristics of the site, which stems from the materials found on the site," explained Kushner. "I think it's a perfect circle." The 3D design scheme stems from the geomorphology of the rocks found in the area, inspiring Kushner to print the entire estate using the rocks for aggregates in the building process. According to 3D Print, using Enrico Dini's D-Shape printers, which differ from the common fused deposition-based models, will allow Kushner to print the necessary materials using on-site resources such as sand, which will be combined with a magnesium-based binding agent. Kushner is still waiting for the delivery of the large-scale 3D printer from Italy. However, if all goes well with US customs and NATO approval, the machine should be on-site in May and the team hopes to begin the first trials and test prints using the new machine by June. Once all of the kinks have been worked out, the team expects to begin 3D printing the pool, followed by the pool house and car port. The last piece of the 3D puzzle will be the most challenging - printing and building the 223 square meters house itself. As far as why this project is so important to Kushner, he explains that by starting on such an ambitiously-sized estate, the 3D home building process can later be used for far more important and diverse tasks, such as producing affordable housing or emergency shelters. "If we can build a pool, then we can begin building reefs, and repair bridges, bulkheads and other underwater structures which there is a huge worldwide need," said Kushner. "The thought is that if we can build a pool house and modest enclosed structure, then it is a short step to building emergency shelters and low cost housing units." Recently a Chinese company WinSun has successfully 3D printed a five-story apartment building and a 110 square meters villa from special print material. China's newest mansion is not only made from recycled materials, but the sprawling 110 square meters home was made with 3D printing. The luxury mansion was 3D printed in layers, using recycled stone and construction waste. Last year the Dutch company DUS Architects developed 3D-printed house using bioplastic.