Rubber Buffings for Bridge Approach Expansion Joints, MLR-01-01, 2001

Many of the bridges in the state of Iowa have type ‘CF’, ‘EE’, or ‘EF’ expansion joints installed in the bridge approach slabs. These joints, which are typically 4” wide, are currently filled with a foam expansion joint material that is covered with a sealant. Over time the sealant begins to pull off of the walls of the joint and it ultimately fails. The joint, which is now exposed to the weather, is then filled with water and solids. The foam joint material, which is lighter than water, floats out of the joint onto the highway. This foam resembles a large 4” X 6” plank and poses a threat to motorists. A possible solution to this problem would be to replace the foam material with rubber buffings. Rubber buffings are a by-product of the tire retread industry.

Evaluation of Fly Ash in Portland Cement Concrete Paving in Woodbury County, Iowa, HR-201, Construction Report, 1979

The earliest overall comprehensive work on the use of fly ash in concrete was reported by Davis and Associates of the University of California in 1937. Since that time there have been numerous applications of the use and varying proportions of fly ash in portland cement concrete mixes. Fly ash is a pozzolanic powdery by-product of the coal combustion process which is recovered from flue gases and is generally associated with electric power generating plants. Environmental regulations enacted in recent years have required that fly ash be removed from the flue gases to maintain clean air standards. This has resulted in an increased volume of high quality fly ash that is considered a waste product or a by-product that can be utilized in products such as portland cement concrete. There are several sources of the high quality fly ash located in Iowa currently producing a combined total of 281,000 tons of material annually. Due to recent cement shortages and the rapidly increasing highway construction costs, the Iowa Department of Transportation has become interested in utilizing fly ash in portland cement concrete paving mixes. A preliminary review of the Iowa Department of Transportation Materials Laboratory study indicates that a substitution of fly ash for portland cement, within limits, is ·not detrimental to the overall concrete quality. Also the use of fly ash in concrete would reduce the cement consumption as well as provide a potential cost savings in areas where high quality fly ash is available without excessive transportation costs. The previously expressed concerns have shown the need for a research project to develop our knowledge of fly ash replacement in the Iowa Department of Transportation portland cement concrete paving mixes.

Laboratory Evaluation of Roller-Compacted Concrete, MLR-86-6, 1988

Fine limestone aggregate is abundant in several areas of the state. The aggregate is a by-product from the production of concrete stone. Roller compacted concrete (RCC) is a portland cement concrete mixture that can be produced with small size aggregate. The objective of the research was to evaluate limestone screenings in RCC mixes. Acceptable strength and freeze/thaw durability were obtained with 300 pounds of portland cement and 260 pounds of Class C fly ash. The amount of aggregate passing the number 200 sieve ranged from 4.6 to 11 percent. Field experience in Iowa indicates that the aggregate gradation is more critical to placeability and compactibility than laboratory strength and durability.

Evaluation of Carbide Waste Lime for Soil Stabilization, Progress Report, HR-111

A lime by-product from the manufacture of acetylene from calcium carbide will be commercially available in Iowa. Since the cost of carbide waste lime f.o.b. source is only about half that of ordinary commercial lime, this material was investigated for potential uses in soil stabilization. The by-product lime is calcium hydroxide in a water slurry with approximately 40% solid concentration. Its effectiveness at stabilizing soils was checked by comparing with commercial high-calcium and dolomitic monohydrate varieties of lime. This was done by soil strength and plasticity tests in addition to studies of the reaction products by X-ray diffraction and chemical methods.

Evaluation of Fly Ash in Portland Cement Concrete Paving in Woodbury County, Iowa, Final Report, HR-201, 1980

The earliest overall comprehensive work on the use of fly ash in concrete was reported by Davis and Associates of the University of California in 1937. Since that time, there have been numerous applications of the use and varying propertions of fly ash in portland cement concrete mixes. Fly ash is a pozzolanic powdery by-product of the coal combustion process which is recovered from flue gases and is, generally associated with electric power generating plants. Environmental regulations enacted in recent years have required that fly ash be removed from the flue gases to maintain clean air standards. This has resulted in an increased volume of high quality fly ash that is considered a waste product or a by-product that can be utilized in products such as portland cement concrete. There are several sources of the high quality fly ash located in Iowa currently producing a combined total of 281,000 tons of material annually.

Production of Acetic Acid for CMA Deicer, HR-304, 1988

Although the overall objective for undertaking this project is to help decide on the best way to produce CMA, the tasks to be performed deal primarily with acetic acid itself. The objectives of our part of this project can be restated here: A. Evaluate the cost and composition of potential low-cost fermentation substrates that are available in large quantity at central locations in Iowa. B. Compare the nutritional and physiological properties of a variety of homoacetogenic bacteria relative to acetic acid production, based on information available in the literature. C. Using both of these pools of information, evaluate the possibilities for use of substrates for acetic acid production that are significantly cheaper than the previous sugar, starch hydrolysate or whole corn based studies; also, compare the different acetogens encountered with the most commonly discussed acetogen, Clostridium thermoaceticum; arrive at conclusions on 1-3 of the best agriculture-derived substrates that should be further examined, and on 1-3 of the best organisms to evaluate experimentally. D. Collect experimental data at the tube and fermentor scale on 1-2 of the possibilities in C above. E. Comment on our understanding of acetic acid production possibilities from our perspective as microbiologists, and provide all this above information to Paul Peterschmidt for him to consider for his portion of this report. F. In addition, we would like to point out the possible advantage of examining the use of an agricultural by-product, corn steep liquor, as a direct, non-fermented feedstock for a non-acetic acid deicer.

Low Cost Fly Ash - Sand Stabilization Roadway, Construction Report, HR-259, 1986

Fly ash, a by-product of coal-fired electricity generating plants, has for years been promoted as a material suitable for highway construction. Disposal of the large quantities of fly ash produced is expensive and creates environmental concerns. The pozzolanic properties make it promotable as a partial Portland cement replacement in pc concrete, a stabilizer for soil and aggregate in embankments and road bases, and a filler material in grout. Stabilizing soils and aggregates for road construction has the potential of using large quantities of fly ash. Iowa Highway Research Board Project HR-194, "Mission-Oriented Dust Control and Surface Improvement Processes for Unpaved Roads", included short test sections of cement, fly ash, and salvaged granular road material mixed for a base in western Iowa. The research showed that cement fly ash aggregate (CFA) has promise as a stabilizing agent in Iowa. There are several sources of sand that when mixed with fly ash may attain strengths much greater than fly ash mixed with salvaged granular road material at little additional cost

Report on a review of the Fuel Inspection Program administered by the Iowa Department of Agriculture and Land Stewardship for the period July 1, 2005 through June 30, 2009

Report on a review of the Fuel Inspection Program administered by the Iowa Department of Agriculture and Land Stewardship for the period July 1, 2005 through June 30, 2009

Estimates of Total Fuel Consumption in Transporting Grain from Iowa to Major Grain-Importing Countries by Alternative Modes and Routes, 1985

This study measured fuel consumption in transporting grain from Iowa origins to Japan and Amsterdam by alternative routes and modes of transport and applied these data to construct equations for fuel consumption from Iowa origins to alternative final destinations. Some of the results are as follows: (1) The metered tractor-trailer truck averaged 186.6 gross ton-miles per gallon and 90.5 net ton-miles per gallon when loaded 50% of total miles. (2) The 1983 fuel consumption of seven trucks taken from company records was 82.4 net ton-miles per gallon at 67.5% loaded miles and 68.6 net ton-miles per gallon at 50% loaded miles. (3) Unit grain trains from Iowa to West Coast ports averaged 437.0 net ton-miles per gallon whereas unit grain trains from Iowa to New Orleans averaged 640.1 net ton-miles per gallon--a 46% advantage for the New Orleans trips. (4) Average barge fuel consumption on the Mississippi River from Iowa to New Orleans export grain elevators was 544.5 net ton-miles per gallon, with a 35% backhaul rate. (5) Ocean vessel net ton-miles per gallon varies widely by size of ship and backhaul percentage. With no backhaul, the average net ton-miles per gallon were as follows: for 30,000 dwt ship, 574.8 net ton-miles per gallon; for 50,000 dwt ship, 701.9; for 70,000 dwt ship, 835.1; and for 100,000 dwt ship, 1,043.4. (6) The most fuel efficient route and modal combination to transport grain from Iowa to Japan depends on the size of ocean vessel, the percentage of backhaul, and the origin of the grain. Alternative routes and modal combinations in shipping grain to Japan are ranked in descending order of fuel efficiencies.