Durability Study of Type II Cements, MLR-71-03 and R-247, 1971

A study of type II cements at the Iowa State Highway Commission concluded that the amount of tricalcium aluminate in the cement appears to have an inverse effect on concrete durability. This conclusion agrees with the results of the Kansas Highway Department's study to determine the combination of cement and aggregate which would produce the best possible durability factor. This study is a result of the questions raised following the completion of the project at the Iowa State Highway Commission. This project is being conducted on a larger scale so. that more definite conclusions can be drawn. The purpose of this project is to determine if the amount of tricalcium aluminate in type II cements has an inverse effect on the durability of concrete.

Absorptive Aggregates in Asphalt Paving Mixtures, HR-142, 1971

In this study, the asphalt absorption of six Iowa limestones were investigated. It was found that the most important factors that determined the nature, amount, and rate of asphalt absorption are porosity and pore-size distribution of the aggregate, viscosity of the asphalt, and time. Methods needed to determine the realistic maximum and minimum asphalt absorption by aggregates are recommended. Simple methods of asphalt absorption were developed. Since the most important factor that determines the accuracy of asphalt absorption is the bulk specific gravity of aggregates and since the current ASTM method is not adequate in this respect, several new methods were developed. Preliminary treatment studies for the purpose of upgrading absorptive aggregates were conducted using close to 40 chemicals. The improvements of some of these treatments on the mixture properties were demonstrated.

Surface Improvement and Dust Palliation of Unpaved Secondary Roads and Streets, Progress Report, HR-151, 1971

A combined study of dust control and low-cost surface improvements of soil and aggregate materials for immediate (and intermediate) use as a treated surface course is being conducted in three concurrent phases: (1) laboratory screening of various additives thought to have potential for long-lasting dust palliation, soil-additive strength, durability, and additive retention potential; (2) test road construction, using those additives from the screening studies that indicate promise for performance and serviceability; and (3) observation and tests of constructed sections for evaluation of the additive's contribution to performance and serviceability as well as relationship to initial costs. A brief review is presented of the problem, some methods of measuring it, previously adopted approaches to it, project field tests and a portion of the results thus far, and portions of the laboratory work accomplished in the screening studies.

La fisioterapia respiratoria: un vantaggio per il trattamento della polmonite?: revisione Cochrane per il medico di famiglia.

Cet article présente les résultats de la revue systématique: Yang M, Yan Y, Yin X, et al. Chest physiotherapy for pneumonia in adults. Cochrane Database of Systematic Reviews 2010, Issue 2. Art. No.: CD006338. DOI: 10.1002/14651858.CD006338.pub2. PMID: 20166082.

Highway "Firsts" - State of Iowa, 1971

Brief summaries of achievement and important events of the Iowa State Highway Commission and transportation engineering in Iowa, between 1904 and 1971.

An Investigation of the Chemical Method of Determining the Cement Content of Hardened Concrete, MLR-71-01 and R-248, 1971

The Iowa State Highway Commission Laboratory is called upon to determine the cement content of hardened concrete when field problems relating to batch weights are encountered. The standard test for determining the cement content is ASTM C-85. An investigation of this method by the New Jersey State Highway Department involving duplicate samples and four cooperating laboratories produced very erratic results, however, the results obtained by this method have not been directly compared to known cement contents of concrete made with various cements and various aggregates used in Iowa.

Collective bargaining in U.S. higher education, 1960-1971 : a selective bibliography, 1972.

This document represents a substantial attempt to survey the literature of labor negotiations as it relates to the faculty in higher education.