The Inorganic Pigments business unit (IPG) of the Lanxess specialty chemicals group has now published a case study on flagship buildings in Colombia. "Colombia Special" from the Colored Concrete Works series of publications describes the Plaza de la Libertad complex in Medellín and the Alianza Francesa in the capital city of Bogotá. The stately structures with impressive architectural features owe their distinctive coloration to pigments from the Lanxess Bayferrox range.

The Plaza de la Libertad is the new face of Colombia's second-largest city. The developer erected an architectural landmark visible from miles around on 12,000 square meters in the heart of the city of Medellín. Rising to the height of 24 and 17 stories, respectively, the two towers are seamlessly integrated into the natural surroundings. With their novel facades and unique coloration, the buildings evoke associations with trees and the structure of bark. Governmental institutions, a business hotel, television studios, businesses, a cultural center, an open-air theater and various exhibitions have found a home in the towers.

The structural elements of the building complex are based on a temperature-regulating and extremely weather-resistant concrete colored with a total of around 70 metric tons of Bayferrox 918 LOM (yellow), Bayferrox 130 (red) and Bayferrox 318 (black) iron oxide pigments. The use of integrally colored concrete offers distinct advantages: Unlike classic paint, it requires no maintenance. The shade was chosen so that the building's appearance remains unblemished even after years of exposure to air pollutants and the weather. Furthermore, the innovative facade helps to reduce the typical HVAC and lighting costs by around 40 percent. In recognition of this, the Colombian Association of Architects awarded the project a prize in an international competition.

Alliance of form and color

The Alianza Francesa in the capital city of Bogotá offers more than 12,500 students 5,300 square meters of space for cultural exchange. The building is a legacy of Colombian star architect Rogelio Salmona, who died in 2007 and was the developer for the Central Administration Building of Alliance Française in Colombia. The building owes its warm ocher yellow glow to the yellow pigments from the Lanxess Bayferrox range used to integrally color the exposed concrete. The stair case configured as a ramp and the hallways prove to be a sophisticated bioclimatic system that completely eliminates the need for air conditioning.

The case study on the two flagship buildings in Colombia is part of the Colored Concrete Works series of publications, with which Lanxess hopes to provide architects with inspiration for their work. The practical examples of outstanding buildings from around the world using colored concrete are available on the Internet at www.colored-concrete-works.com.

"Colombia is a very important country for our business unit with interesting growth potential," says Lothar Schwarz, the Lanxess IPG sales and marketing manager responsible for the Latin American market. "We are presenting these outstanding examples in recognition of that fact."