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BY ZACH MORTICE

Witness Walls is composed of two different types of concrete walls, one with soft, impressionistic imagery and the other with sharper image contrasts. Photo by Stacey Irvin.

 

Correction appended August 24, 2017.

Many cities where African Americans fought for equality in the 1950s and 1960s are associated with violence: Selma, Memphis, Birmingham. Nashville wasn’t such a place. Its civil rights story was nonviolent and “so successful we don’t know about it,” says Walter Hood, ASLA, who was asked to commemorate this history with a public art installation.

Nashville was a leader in civil rights. It desegregated its public schools relatively early, in 1957, and its activist community and local pastors offered the same suite of training and conditioning for student protestors that many southern cities did. After a historic protest, then-Mayor Ben West was forced to desegregate the city’s lunch counters.

The site of this protest is now home to a commemorative public art and landscape installation by Walter Hood: Witness Walls, for the Metro Nashville Arts Commission, completed in April. It’s the city’s first (more…)

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BY MEG CALKINS, FASLA

New technologies can reduce the environmental footprint of the most-used construction material.

FROM THE JULY 2017 ISSUE OF LANDSCAPE ARCHITECTURE MAGAZINE.

Concrete in the 21st century promises to be a more sustainable material, and given the nine billion metric tons used globally each year, it must be. Portland cement, the binding agent in ordinary concrete, has a very high carbon footprint, resulting in just under one ton of carbon dioxide (CO2) released for every ton of cement produced. With 4.2 billion metric tons of the binder used each year worldwide, cement production is responsible for nearly 8 percent of total global carbon emissions. The high lime content of ordinary portland cement contributes about two-thirds of cement’s CO2 impact through the process of limestone calcination. The other one-third of CO2 released is from combustion of fossil fuels.

Technologies to improve the carbon footprint of concrete are currently in the early stages of development, but some, including carbon sequestration in concrete and substantial reductions of cement using energetically modified cement, are now commercially available. Concrete surface products for paving and walls to scrub air pollution, as well as new self-healing concrete products, are also worth investigating. We have heard about some of these innovations for a decade or more in the research community, but many are finally being brought to market—some more quickly than others. Europe is ahead of the United States in the adoption of these technologies, largely because of more rigorous clean air and carbon reduction initiatives.

New technologies in any field can take a long time to move from the laboratory to the marketplace, but (more…)

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BY NEIL BUDZINSKI AND MATTHEW GIRARD

A forensic approach found the best decomposed granite solution for Kenyon College.

A forensic approach found the best decomposed granite solution for Kenyon College.

From the November 2016 Issue of Landscape Architecture Magazine 

Decomposed granite pavement (DG) is a textured and responsive paving material used on paths and plazas. Yet the quiet appearance of DG masks material and construction complexities that shape the outcome of the built work and belie what may appear to be a simple installation. In 2010, Michael Van Valkenburgh Associates (MVVA), where we are senior associates, was hired to prepare a master plan for Kenyon College in Gambier, Ohio. Over several years of our working with Kenyon to renovate its historic Middle Path, the challenges of this material were revealed and met through a program of design-phase mock-ups, manufacturer’s product development, and innovations in installation methods. We have learned several lessons regarding the product and the methods that change the way we specify and oversee the installation of this seemingly simple material.

Kenyon’s landscape is organized around Middle Path, a 3,600-foot-long walk made from a local river stone. The material of Middle Path, cherished for its color, texture, looseness, and sound, (more…)

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