There is literally concrete evidence of their work." Tony Hawk says skateboarding was once a sport on the edge of society.
VOA: special.2009.09.11
The National Ready Mixed Concrete Association points out that using ash in cement is not a new idea.
VOA: special.2009.12.01
Men in two special factories worked day and night to make the concrete building material for the dam.
VOA: special.2009.08.12
Workers also used more than twenty million kilograms of steel to strengthen the concrete in the dam.
VOA: special.2009.08.12
Kahn was able to make the concrete material of the building look both solid and airy.
VOA: special.2009.12.13
The idea is to replace some of the portland cement traditionally used in making concrete.
VOA: special.2009.12.01
The Portland Cement Association says the gas from the limestone is reabsorbed as concrete ages.
VOA: special.2009.12.01
On June sixth,nineteen thirty-three, workers poured the first load of a building material called concrete.
VOA: special.2009.08.12
Portland cement is a material that holds together the sand and crushed stone in concrete.
VOA: special.2009.12.01
Costas Synolakis says Japan's concrete sea walls were not built to handle such high waves.
VOA: special.2011.03.21
For example,he created a triangle-shaped walkway of steps that sits inside a rounded concrete shell.
VOA: special.2009.12.13
Rock walls made of wood or concrete have places for the climber's hands and feet.
VOA: special.2009.12.09
Rajan Vempati thinks rice hull ash could help the concrete industry produce less carbon dioxide.
VOA: special.2009.12.01
A concrete bridge was built about two hundred seventy-five meters above the Colorado River.
VOA: special.2010.10.27
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