Recommendations for Special Specifications, Covering Basic Lead Silico-Chromate, Oil-Alkyd, Vinyl-Alkyd Paints for Bridges

This specification covers the material requirements for a Basic Lead Silico-Chromate, Oil-Alkyd Paint System intended for use on exterior iron and steel structures (bridges), for either new or re-paint work, except where exposed to severely corrosive conditions such as within the splash-zone from bridge decks or on other members likely to be affected by de-icing salts or persistent moisture conditions. This system shall consist of a primer-, intermediate-, and finish-coat paint as hereafter specified. Uses of the component paints other than as an integral part of this system are specifically excluded

Porous Sand-Asphalt Mixtures

Size is relative. Densely graded sand-asphalts are relatively similar to conventional, bituminous concretes. Porous sand-asphalts possess the same attributes as other porous, bituminous mixtures. Surely, sand-asphalt mixtures, can be designed to be as porous as the so-called, open-graded plantmix seals. Particle shape and texture otherwise define skid-resistance. Stability remains an assurance against scaling. Stability is assured by maximum utilization of filler-bitumen ratio and the stiffness of asphalt cement

Manufactured (Crushed), Limestone, Fine Aggregate for Portland Cement Concrete

Manufactured (crushed), limestone, fine aggregate for use in structural concrete, concrete base courses for pavements, or as may otherwise be designated, shall be manufactured by crushing and sizing aggregate-quality limestones and dolomites. Manufactured (crushed), limestone, fine aggregate shall not be used in concrete surface courses for pavements or bridge decks unless specifically authorized by the Engineer

Experimental Feature, Construction Project F 160(10), U.S. 127, Mercer County, Experimental Guardrail Installations and Performance Studies

The report submitted herewith pertains to an experimental installation of aluminum guardrails which was completed in February, 1963. Progress reports, as required by PPM\u27s 60-2 and 50-1.1, have been pending since the project began; however, all of the eligible information has been combined into the current report. Of course, long-time performance histories cannot yet be documented; and, for that reason, the report is considered to be interim rather than final

Experimental Applications of Protective Coatings to Shales Exposed in Highway Cuts

Many shales exposed in roadway cut-sections are susceptible to weathering, slaking, and erosion; fallout and taluses clog drainage; benches overflow; and occasionally landslides or rockslides develop. Presently, in design, certain types of shales and even named formations are afforded wider benches than others; soil mantles at the tops of cuts are being stripped back farther; and, of course, sound ledge-rock offers the preferred type of bench-cap. Pre-splitting methods of blasting have greatly enhanced the appearance of cuts and have minimized the shattering of cut faces. The resulting surfaces frequently are quite smooth when first exposed and remain so if the materials are resistant to weathering and erosion. However, erosive shales interbedded between sound rock ledges may eventually cause trouble

Research Relating to State Highway Laws

The Department\u27s study began late in 1962 and was undertaken as a review and analysis of the main body of highway law; but, of course, any subsequential objectives--stated or implied-remained contingent upon and would become a natural consequence of the first-mentioned type of inquiry and the improbablity of discovery. Undoubtedly, the Department was influenced by and was under inducement of the Bureau of Public Roads in this undertaking, The review-and-analysis phase was accomplished, in part, by the School of Law, University of Louisville, acting under contract (CH119 36, dated November 15, 1962) which was subsequently dissolved (9-30-63); a draft report issued therefrom (October 1963) and remains the principal instrument of the study. Subsequent phases, as originally proposed, were suspended-thereby rendering intangible any accrual of direct benefits gained from the review and analysis. Nevertheless, the summary, which follows, reflects implied, emergent, and perhaps latent, influences of the study

Hot Mix Sand Surfacing

Everyone has some compassion toward drivers who become victims of pavement slipperiness. The development of slipperiness on a road surface follows one of the laws of nature. Why not, then, employ other laws provided by nature to better advantage? For example, craftsmen use grinders, abrasives, buffers, etc. to achieve glossy surface finishes. Traffic does the same to our pavements. We might employ craftsmens\u27 routine in reverse -- that is, roughen the surface. Better still, the principles that are apparent in a grinding wheel or whetstone may be used as a model for our pavement surface: a material of hard, abrasive granules glued together. If the glue is too hard, the abrasive particles themselves become dull and polished, the pores clog, and the wheel will not cut. A wheel or hone designed to do a specific job must be able to let go of a dulled particle and expose a new, sharper particle from underneath. In other words, the wheel must undergo a controlled type of wear -- or else be dressed and re-roughened periodically. This is the analogy of a hot-mixed sand-asphalt pavement surface