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ACI Spring 2010 Convention
March 21 - 25, 2010
Marriott Rivercenter Hotel & Henry B. Gonzalez Convention Center -- San Antonio, TX

NRMCA Sustainable Conference
April 12 - 15, 2010
Tempe, AZ

International Parking Institute Conference & Expo
May 10 - 12, 2010
Mandolay Bay - Las Vegas, NV

International Bridge
Conference 2010

June 6 - 9, 2010
David L. Lawrence Convention Center - Pittsburgh, PA

ACI Fall 2010 Convention
October 24 - 28, 2010
The Westin Convention Center -- Pittsburgh, PA

Chapter 2 - Using Silica Fume in Concrete
Improving Durability

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This project was done at the United States Borax & Chemical Corporation plant in Boron (Death Valley), California. Concrete containing ten percent silica fume was used for a slab and a drainage ditch. Both are exposed to sulfuric acid and borax. The water-cementitious material ratio of the concrete was approximately 0.40. As might be expected for Death Valley, conditions during the placement were extremely harsh: the estimated rate of evaporation from the concrete surface was over 3.9 L/m2/h (0.8 lb/ft2/hr), which is almost four times the rate at which ACI recommends taking precautions to prevent plastic shrinkage cracking for concrete without silica fume. For this project, the concrete was fogged until curing compound was applied. Wet burlap covered by plastic sheeting was placed over the curing compound. The concrete also contained polypropylene fibers to help protect against plastic cracking. The concrete was placed and cured without cracking. This slide shows preparation for placement of the slab.