The Constructions of Deduction

As cities across the US build bike lanes, their decisions are often seen as a move to give space to bikes at the expense of cars. But data tells us this isn't always true: In New York City, for instance,  bike lanes have actually shortened cars' travel times  on several streets, while simultaneously encouraging people to bike and making it safer. How can this be? Two words:   road diets . The video above — created by city planner Jeff Speck and artist Spencer Boomhower — nicely explains four types of road diets, a trend that has become increasingly popular in US cities over the past few decades. These diets can take several forms, but the basic idea is that by removing traffic lanes, cities can free up space for bike lanes and  reduce the frequency of crashes . Narrowing lanes  from 12 feet to 10 , meanwhile, makes drivers less likely to speed, and in doing so has also been shown to  cut down on crashes  that involve...

Sika AG  is a globally active specialty chemical company in Switzerland. Sika supplies and manufactures the products for construction and industry.

Complementing the Government of Malaysia's efforts to encourage the use of environmentally friendly materials in the construction of green buildings, researchers from the faculty of civil engineering, University Technology MARA in Malaysia have successfully developed an environment friendly version of building concrete called green-mix concrete. When it comes to building structures, developers and contractors have the advantage of choosing from a variety of materials to use. Generally, the decision on material choice depends on several factors including cost and performance for specific applications. Due to growing interest in sustainable development and various incentives provided by the Government of Malaysia, the key players in the construction industry are motivated more than ever before to use materials that are sustainable or in such a way that their environmental impact is minimal. In 2009, the Malaysian government launched the green building index (GBI) to en...

"Eco-Towers: Sustainable Cities in the Sky" describes groundbreaking designs and built projects around the world, with 250 color photographs and drawings. The book explores seawater-powered air conditioning, large-scale recycling of gray and black water, helical wind turbines and sunlight-sensing LED lights. As architects design taller buildings that serve more people and demand more from the environment and infrastructure, any improvement in their design and construction will benefit cities, says Kheir Al-Kodmany, professor of urban planning and policy. "A tall building is an integral piece of the city infrastructure," he says. "The true green skyscraper is one that forms symbiotic relationships with the social, economic, environmental and transportation aspects of its urban context." Formerly an architect with Skidmore, Owings & Merrill, Al-Kodmany teaches urban design and served as a consultant on high-rise development in Amman, Jo...

Skyscrapers have long been a contest of sorts. Owners are secretive about the actual height of their buildings, so that others do not eclipse them before their time as tallest has come. The tricks that designers use to inflate tall buildings' heights are impressive, too. Spires and decorative elements are often used to get those last few precious feet. But underneath these shiny glass facades is another trick. A recent Council on Tall Buildings and Urban Habitat (CTBUH) study illustrates that big chunks of useless space are hidden at the top of many of the world's skyscrapers in order to inflate their height. In fact, as much as one-third of a building's height can be "vanity space." Consider it space as decoration. Burj Khalifa The building that is set to be the world's tallest, the Kingdom Tower in Jeddah, Saudia Arabia, set off the Council's alarms. A case study suggested that the structure was designed with decorative, height-in...

Traffic and Highway Engineering, Fourth Edition Nicholas J. Garber and Lester A. Hoel Click here to download

New Technologies Push Strengths to New Heights As recently as 25 to 30 years ago, the steadily increasing availability of concrete with compressive strengths above 6,000 psi had the industry’s rapt attention. Back then, in many regions, strengths this high were considered revolutionary. Some people even questioned the need. Fast forward to 2014, and designers are specifying strengths of 10,000 psi, 12,000 psi and higher. A new 42-story residential tower in downtown Seattle is one of the first in the country to use 15,000 psi concrete in its columns, reflective of the recent advances in concrete materials technology. Used effectively, this “super concrete” allows smaller columns, shorter and thinner shear walls, and reductions in other structural elements. This results in additional interior real estate. And, when this concrete is paired with modern high-production formwork and the advanced pumping technologies now available, the sky is quite literally the limit. Concrete Advan...