High Performance Concret Bridge Deck Overlays for County Bridges, October 2007

The Iowa Method for bridge deck overlays has been very successful in Iowa since its adoption in the 1970s. This method involves removal of deteriorated portions of a bridge deck followed by placement of a layer of den (Type O) Portland Cement Concrete (PCC). The challenge encountered with this type of bridge deck overlay is that the PCC must be mixed on-site, brought to the placement area and placed with specialized equipment. This adds considerably to the cost and limits contractor selection. A previous study (TR-427) showed that a dense PCC with high-range water reducers could successfully be used for bridge deck overlays using conventional equipment and methods. This current study evaluated the use of high performance PCC in place of a dense PCC for work on county bridges. High performance PCC uses fly ash and slag to replace some of the cement in the mix. This results in a workable PCC mix that cures to form a very low permeability overlay.

Audit report on Ida County, Iowa for the year ended June 30, 2008

Audit report on Ida County, Iowa for the year ended June 30, 2008

Audit report on the Wayne-Ringgold-Decatur County Solid Waste Management Commission for the year ended June 30, 2008

Audit report on the Wayne-Ringgold-Decatur County Solid Waste Management Commission for the year ended June 30, 2008

Audit report on O’Brien County, Iowa for the year ended June 30, 2008

Audit report on O’Brien County, Iowa for the year ended June 30, 2008

Audit report on Monona County, Iowa for the year ended June 30, 2008

Audit report on Monona County, Iowa for the year ended June 30, 2008

Audit report on Mills County, Iowa for the year ended June 30, 2008

Audit report on Mills County, Iowa for the year ended June 30, 2008

Audit report on Wayne County, Iowa for the year ended June 30, 2008

Audit report on Wayne County, Iowa for the year ended June 30, 2008

Audit report on Jackson County, Iowa for the year ended June 30, 2008

Audit report on Jackson County, Iowa for the year ended June 30, 2008

Audit report on Montgomery County, Iowa for the year ended June 30, 2008

Audit report on Montgomery County, Iowa for the year ended June 30, 2008

Audit report on Pocahontas County, Iowa for the year ended June 30, 2008

Audit report on Pocahontas County, Iowa for the year ended June 30, 2008

Audit report on Washington County, Iowa for the year ended June 30, 2008

Audit report on Washington County, Iowa for the year ended June 30, 2008

Iowa County Precipitation Estimates, 2008

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau.

County Precipitation Estimates, January 2008

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau.

Iowa County Precipitation Estimates, Departure from Normal 2008

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau.

Iowa County Precipitation Estimates, Departure from Normal 2008

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau.