Highway Surface Research Articles

Distribution and Origin of Magnetite Spherules in Air, Waters, and Sediments of the Greater New York City Area and the North Atlantic Ocean

ABSTRACT Perfectly spherical sand to clay size particles composed of magnetite occur in a wide variety of environments. Within the greater New York City area such spherules are found in smoke-stack filtrate, urban-air filtrate, ditritus collected from highway surfaces, lake sediments, marsh sediments, and in beach sands. The abundance of spherules in such environments diminishes away from industrial centers. The abundance of magnetite spherules in core samples of lake and marsh sediment decreases sharply near the palynologically determined stratigraphic boundary separating sediments deposited before the area was settled and industrialized from sediments deposited afterward. Their abundance in samples of deep ocean-floor sediment also drops off sharply within the upper 10 cm of core. The spheru es become rare to absent below this depth. We conclude that the great majority of magnetic spherules presently accumulating in sediments are of industrial origin, while we recognize the existence of spherules of probable extraterrestrial origin in ancient sediments. The ease of identification and recovery of magnetite spherules from sediments facilitates their use as indicators of probable post-industrial age.

FATIGUE ANALYSIS OF HIGHWAY BRIDGES

The increased possibility of minor as well as major fatigue failure of highway bridges of relatively short span now being subjected to heavy trucks more frequently than ever before, appears to be a critical problem that calls for a basic re-evaluation of the fatigue performance of these bridges constructed under current and past design codes. For the purpose of establishing a framework of the study along this line, the present paper outlines, with a numerical example, a method of sensitivity analysis for the fatigue failure dealing with a system of a simple bridge and moving vehicles. Specifically, the sensitivity of the expected fatigue life to various parameters of the bridge and traffic flow characteristics such as failure criterion, traffic intensity, highway surface roughness, bridge damping, etc. Is investigated. (A) /TRRL/

The Application of Latex to Highway and Floor Surfacing

Abstract Investigations on the development of latex mixtures for roadways were carried out in Malaya by Hastings during the period 1931 to 1933. Of the different mixtures tried, those containing aluminous cement gave the most promising results. Considerable progress of a practical character in working out the details of a suitable cement-latex mixture was then made, culminating in the laying in 1933 of an experimental section of road 4.5 miles from Kuala Lumpur on the Kuala Lumpur—Port Swettenham Road, where the traffic is fast and fairly heavy. In view of the promising results obtained in these experiments, it was agreed that the subject should be studied further in London, and that particular attention should be given to obtaining a better understanding of the fundamental principles involved in the preparation of latex mixtures for road and floor surfacing. As the economic factors are less exacting for flooring than for highways, it was decided that the application of latex mixtures to flooring should receive prior attention. The main purpose of the investigation has now been fulfilled, and this paper presents a summary of the work carried out and the results obtained. Mixtures of aluminous cement and latex have been in use for some time, both for flooring and other purposes; as early as 1923–4 patents were obtained for mixing cement with specially treated latex. The theory underlying this process is that the cement combines with the water of the latex and becomes hydrated, the latex losing its water and coagulating. How far this occurs in practice was not established at the outset of the work in London, and attempts were made to determine the extent of hydration of the cement and to examine the microstructure of the mixtures. During the course of this work it became apparent that the structure and physical characteristics of the products were largely dependent on the materials used in compounding and especially on the latex stabilizer. A systematic study of the principles underlying the compounding of the mixtures was then undertaken, and the relationship between compounding and physical properties determined. It thus became necessary to develop a series of tests to measure the physical properties, as no suitable methods were available. As a result of these experiments, a number of cement-latex compositions were developed and the most suitable selected for small scale trials. A summary of the work carried out and the conclusions reached are given in the following sections.

TAILOR‐MADE HIGHWAY SURFACE

School Science and MathematicsVolume 33, Issue 1 p. 111-111 TAILOR-MADE HIGHWAY SURFACE First published: January 1933 https://doi.org/10.1111/j.1949-8594.1933.tb17109.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume33, Issue1January 1933Pages 111-111 RelatedInformation

An Aurora on November 23

STEPPING out of doors to-night, November 23, at 7.30, I was surprised to see the whole northern sky filled with luminous mist, so clear that our shadows were dimly observed on the shining surface of the wet highway. There were few tremulous motions, but the light clouds advanced southwards in great patches. For a while the planet Jupiter shone to the east of the luminous haze. Then the mist passed over Jupiter, who shone, however, with nearly its wonted splendour until a great detached belt hung between Jupiter and Pleiades, over to the south-west horizon.