The National Ready Mixed Concrete Association points out that using ash in cement is not a new idea.

VOA: special.2009.12.01

As a final step there are plans to pump in mud and cement from below through relief wells.

VOA: special.2010.08.07

But cement manufacturing produces around five percent of the carbon dioxide released by human activity worldwide.

VOA: special.2009.12.01

I hurried to put the last stone into the wall and put the cement around it.

VOA: special.2009.02.07

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

Carbon dioxide is released in cement manufacturing when fuel is burned and limestone is heated.

VOA: special.2009.12.01

Portland cement is a material that holds together the sand and crushed stone in concrete.

VOA: special.2009.12.01

Other materials such as lime and cement can be added to strengthen the adobe.

VOA: special.2009.01.12

Workers later added cement to harden in the well to seal it permanently.

VOA: special.2010.08.07

Then,she started making statues out of cement material and glass.

VOA: special.2010.04.14

The ancient Romans discovered that volcanic ash made better cement.

VOA: special.2009.12.01

Although Israel bans cement to keep Hamas from building bunkers, streets are being repaired, and some public works projects are proceeding.

VOA: standard.2010.06.16

Norma Fiorentino's water well blew up on New Year's Day 2009, throwing cement slabs into the air.

VOA: standard.2010.01.02

"Now it's a lot more organized." Competitors tee off from cement tee pads, working their way along a beautiful disc course that winds around cornfields, wind turbines,and a football field.

VOA: standard.2010.08.03

they mix cement; they carry buckets; they clean up.

VOA: standard.2010.02.24