RAGBRAI Learn about the Land; Day 5, July 2008

Today, after you descend into the valley of the Iowa River north of Marengo, the route turns east on county road F15 and approaches the historic Amana Society. Settled in the late 1850s by German immigrants of the Community of True Inspiration, the new arrivals utilized the local timber and stone resources to construct their buildings. During these early years several stone quarries were opened in the hills along the north wall of the Iowa River valley near East, Middle, and West Amana. Riders will pass close to one of these old quarries 0.7 miles west of West Amana. The stone taken from these quarries is beautiful quartz-rich sandstone that is cemented by light brown to orange tinged iron oxide. This stone was used in the construction of many buildings in Amana.

Reclaimed Fly Ash as Select Fill Under PCC Pavement, November 1999

With the support of the Iowa Fly Ash Affiliates, research on reclaimed fly ash for use as a construction material has been ongoing since 1991. The material exhibits engineering properties similar to those of soft limestone or sandstone and a lightweight aggregate. It is unique in that it is rich in calcium, silica, and aluminum and exhibits pozzolanic properties (i.e. gains strength over time) when used untreated or when a calcium activator is added. Reclaimed Class C fly ashes have been successfully used as a base material on a variety of construction projects in southern and western Iowa. A pavement design guide has been developed with the support of the Iowa Fly Ash Affiliates. Soils in Iowa generally rate fair to poor as subgrade soils for paving projects. This is especially true in the southern quarter of the state and for many areas of eastern and western Iowa. Many of the soil types encountered for highway projects are unsuitable soils under the current Iowa DOT specifications. The bulk of the remaining soils are Class 10 soils. Select soils for use directly under the pavement are often difficult to find on a project, and in many instances are economically unavailable. This was the case for a 4.43-mile grading (STP-S- 90(22)-SE-90) and paving project in Wapello County. The project begins at the Alliant Utilities generating station in Chillicothe, Iowa, and runs west to the Monroe-Wapello county line. This road carries a significant amount of truck traffic hauling coal from the generating station to the Cargill corn processing plant in Eddyville, Iowa. The proposed 10-inch Portland Cement Concrete (PCC) pavement was for construction directly on a Class 10 soil subgrade, which is not a desirable condition if other alternatives are available. Wapello County Engineer Wendell Folkerts supported the use of reclaimed fly ash for a portion of the project. Construction of about three miles of the project was accomplished using 10 inches of reclaimed fly ash as a select fill beneath the PCC slab. The remaining mile was constructed according to the original design to be used as a control section for performance monitoring. The project was graded during the summers of 1998 and 1999. Paving was completed in the fall of 1999. This report presents the results of design considerations and laboratory and field testing results during construction. Recommendations for use of reclaimed fly ash as a select fill are also presented.

Pieces of Iowa’s Past, April 17, 2013

Pieces of Iowa’s Past, published by the Iowa State Capitol Tour Guides weekly during the legislative session, features historical facts about Iowa, the Capitol, and the early workings of state government. All historical publications are reproduced here with the actual spelling, punctuation, and grammar retained THIS WEEK: Iowa State Capitol Structural Sandstone Origination From The Iowa Capitol Commissioners Reports Report of Capitol Architect A.H. Piquenard, submitted December 16, 1875 BACKGROUND: The Ste. Genevieve sandstone is the buff color stone on the exterior of the Capitol. The Carroll County sandstone was the light color or contrast stone on the Capitol exterior. The Carroll County stone did not wear well and was removed from the building during the exterior renovations in the 1980s and 1990s. Both sandstones are from Missouri.