Agreed-upon procedures report on the City of Wall Lake, Iowa for the period July 1, 2014 through June 30, 2015

Agreed-upon procedures report on the City of Wall Lake, Iowa for the period July 1, 2014 through June 30, 2015

Air Formed Arch Culvert Construction: Crawford County, Construction Reports, HR-314, 1991

Iowa's secondary roads contain nearly 15,000 bridges which are less than 40 feet (12 m) in length. Many of these bridges were built several decades ago and need to be replaced. Box culvert construction has proven to be an adequate bridge replacement technique. Recently a new bridge replacement alternative, called the Air-0-Form method, has emerged which has several potential advantages over box culvert construction. This new technique uses inflated balloons as the interior form in the construction of an arch culvert. The objective of research project HR-314 was to construct an air formed arch culvert to determine the applicability of the Air-O-Form technique as a county bridge replacement alternative.

Field Evaluation of Cold In-Place Recycling of Asphalt Concrete, HR-303, Construction Report, 1990

There are still many vintage portland cement concrete (PCC) pavements, 18 ft wide (5.4 m), dating back to pre-World War II era in use today. Successive overlays have been placed to cover joints and to improve rideability. The average thickness of the existing asphalt cement concrete (ACC) along route E66 in Tama County, Iowa, was 6.13 in. (15.6 cm). The rehabilitation strategy called for widening the base using the top 3 in. (7.6 cm) of the existing ACC by a recycling process involving cold milling and mixing with additional emulsion/rejuvenator. The material was then placed into a widening trench and compacted to match the level of the milled surface. This project was undertaken to develop a rehabilitation methodology to widen these older pavements economically and to have a finished surface capable of carrying traffic with little or no additional work.

Computer Analysis of Twin Box Culverts, 1959

The paper presents a method of analyzing Rigid Frames by use of the Conjugate Beam Theory. The development of the method along with an example is given. This method has been used to write a computer program for the analysis of twin box culverts. The culverts may be analyzed under any fill height and any of the standard truck loadings. The wall and slab thickness are increased by the computer program as necessary. The final result is steel requirements both for moment and shear, and the slab and wall thickness.

Effect of a Noise Wall on Snow Accumulation and Air Quality, 1985

A noise wall was investigated to assess its effect on snow accumulation and air quality. Wind tunnel studies were undertaken to evaluate (a) possible snow accumulations and (b) the dispersion of particulate concentrations (dust, smoke, and lead particles) and carbon monoxide. Full-scale monitoring of particulate concentrations and carbon monoxide was performed both before and after the noise wall was constructed. The wind tunnel experiments for snow accumulation were conducted on a model wall located in a flat, unobstructed area. A separated flow zone existed upwind of the wall and snow immediately began to accumulate over most of the separated zone. Having the noise wall in an aerodynamically rough area, such as in an urban area as this one was, substantially decreased the amount of snow collected, compared with in the wind tunnel studies, because of turbulence reducing the separation zone. The snow accumulation has not been significantly greater with the noise wall in place than it was before construction and has proven to be of no concern to date. Monitoring for particulate concentrations has shown that the noise wall has had a beneficial effect because the amount of material collected was reduced. With the noise wall in place, monitoring for carbon monoxide has indicated that (a) for equivalent emissions under conditions of high atmospheric stability and low wind speeds, the carbon monoxide levels would be lower; and (b) under conditions of low atmospheric stability and high wind speeds, the carbon monoxide levels would be higher than expected without the wall in place.