Certain areas of Iowa abound in loess, others contain soft limestones that are readily and cheaply available, and a large portion of the state is underlaid with sand. None of these materials is considered suitable in present practices for use in all-weather road construction. The loess is too fine and too difficult to handle; the limestones are considered too soft, and some of the harder ones unsound for this use; the sands are not naturally of the desired gradation and do not lend themselves to blending into satisfactory gradations. The purpose of this project is, therefore, to study and develop means and to determine the feasibility of using these materials, loess, fine sand, and soft limestones, either separately or in combinations in conjunction with liquid binders to produce paving mixtures applicable for all-weather road construction. Also included in the project was the development of methods of processing any of these materials, if necessary, to make them suitable for the desired purpose.
The chemical process of oxidative age-hardening in asphalt pavements is one of the major distressesleading to hot mix asphalt (HMA) pavement failure a...
2023-06-30 | FHWA Highway History Website Articles
Abstract:
One of the universal truths is that road construction is dependent on the materials at hand. At one time or another, almost every material common to a...
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