Traffic Paint Service Tests for 1954

This report documents the performance data obtained by the Research Laboratory in connection with field service tests and laboratory tests on traffic paint samples submitted by prospective suppliers for 1954. On the basis of these data and the adjudged performance of the samples offered, invitations to bid will be issued to any or all suppliers offering worthy materials. (See Division of Purchases\u27s Memorandum of January 7, 1953 in Appendix) Winning bidders should be bound by oath to supply the same formulation of materials as furnished in the qualifying samples, and they should be further bound by such tests and analyses as may be considered necessary by the Dpeartment of Highways in establishing verification

Experiments with Air Entrainment in Cement Concrete

In September, 1946, the Research Laboratory prepared and distributed a comprehensive report entitled. A Summary of Experiments With Air Entrainment in Cement Concrete , which covered field and laboratory experimentation conducted over a period of six years. In February, 1947, specific recommendations based on this report and another dealing with the pressure method of determining air contents resulted in adoption of air entrainment for all concrete pavements and the pressure method as the only accepted method of control. Among the several projects included in the six years of research were four experimental roads which, of course, are still in service. Although these roads have served their primary purpose from the standpoint of experimentation, there is still much to be gained by periodic inspection of them and careful recording of their progress, especially in view of the fact that five to six year\u27s exposure did not cause appreciable deterioration of the pavements. Accordingly, all four projects were examined during the past summer, and this is a report of their progress as determined by these examinations

Study of the Effect of Blended Coarse Aggregate on Air Entrained Concrete Second Progress Report

When the first progress report on this study of blended aggregate was prepared in January, 1947, only three of the nine groups of samples in Series I had completed the durability tests, and specimens in four of the seven groups composing Series II had not even been prepared. In contrast, at the present all samples in Series I have completed the durability tests thus concluding the results pertaining to Ohio River gravel from Louisville, and specimens in three groups of Series II (applicable to glacial gravel) have finished the durability tests. Further than that, several additional groups of samples which form a part of the over-all study of combined aggregate materials have been prepared in the interim, and some of these were placed in durability tests several weeks ago. These, however, are of doubtful ultimate value because of defects in operation of equipment, and for that reason--plus the fact that nothing of significance has shown up in the tests--they are not given consideration in this report. As shown in Table I, where the results are summarized, only four sets (or two groups) of specimens were able to withstand freezing and thawing for 200 cycles - the maximum duration of test or point at which beams were removed if failure had not occurred previously. These samples were in Series I, Group G, where the mix contained 100 percent limestone coarse aggregate and 4.3 percent air, and Series II, Group A, which had 100 percent glacial gravel and 6.1 percent air in the mix. Apparently, the unusual durability of the latter must be dependent upon its high air content, because mixes with the same aggregate but only 1.7 percent air (Series C) or even 4.1 nercent air (Series B) could withstand not more than 172 cycles. Thus, for practical purposes all mixes except those with 100 percent limestone and air entrainment failed in less than 200 cycles

A Summary of Experiments with Air Entrainment in Cement Concrete

Field and laboratory experiments designed to show the merits of air-entrainment in cement concrete have been conducted by the Department of Highways since 1940. During that time six laboratory projects with many variables have been completed, and most of these were directly related to the four experimental roads which have been in service from four to six years. Collectively these experiments form a moderately comprehensive analysis of the features of air-entrainment, still there are many points which have not been fully covered either because of limitations in time and personnel or because of new developments which render some of the 1940 experiments obsolete in detail

Outline of Research for Adhesion of Bituminous Materials to Mineral Aggregates

The primary object of this proposed research is to investigate existing procedures or develop new means for evaluating the adhesive capacity of bituminous materials when applied to mineral aggregates. This includes bituminous materials in combination with additives or so-called anti-stripping agents; hence, the scope of the project includes: A study of aggregates for hydrophyllic or hydrophobic properties as related to different types of bitumen, and the selection of a standard aggregate by which the adhesion of bituminous materials themselves may be judged. Comparison of grades and sources of bituminous materials with respect to power of adhesion to (or tendencies to strip from) different aggregates, both when used separately and when combined with anti-stripping agents. Evaluation of different products sold commercially as additives to prevent stripping. The ultimate aim is to establish acceptance tests and specifications that can be applied to both the bituminous materials and the additives

Outline of Proposed Study of Sands Used as Concrete Fine Aggregates

This investigation is being made for the purpose of evaluating fine aggregates for concrete in which the percentages of fines, finer than the No. 50 and the No. sieves, are increased over that in the normal commercial sands meeting the present specifications for Class A concrete. It is a continuation of the studies made in Research Projects C-14 and C-15 (Reports submitted January, 1946), but enlarged to include physical tests on sand, and tests on mortar specimens, as well as the usual tests on concrete specimens

Vibratory Compaction of Base Courses

Early this month, on a field trip with Mike Logan of tho Bureau of Public Roads and R. D. Medley, Asst. Director of Design, I had an opportunity to look over a project in Ohio where a vibratory method of compaction was being used in tho construction of a macadam base course, This type of compaction is relatively new, it having been tried for the first time in this country about four years ago, To my knowledge, the first published report on the procedure was made in the Proceedings of the Highway Research Board, Volume 27, page 148, 1947. This report, by Messrs. Allen and Linzell, entitled Use of Vibration In Placing Screenings In Macadam Bases described the two types of machines which were tried experimentally, and illustrated some of the results

Research with Mulches for Roadside Grasses

At the January 27, meeting of our Research Board,experiments with mulches for roadside grasses as proposed by a committee of the Highway Research Board, National Research Council, was discussed. The matter – as noted in item 7 of the minutes of that meeting – was directed to Professor Shaver and me with a request by Mr. Cutler that we confer with men in the Agricultural Experiment Station, University of Kentucky, and at our next meeting report on the practicability of these experiments. On the afternoon of March 7, Prof. N.R. Elliott, Acting Head of the Department of Horticulture at the University, Prof. Shaver, and I had a conference in our Research Laboratory. Prof. Elliott reviewed the proposed experiments, commented on the favorable and unfavorable aspects, and in general made counter proposals which he though could be correlated with the Highway Research Board objectives but which would be more suited to conditions peculiar to Kentucky. These suggestions are outlined on the attached sheet, the original of which was prepared by Prof. Elliott. Further appears to be in order before more specific action regarding experiments can be taken

Stability Investigation of Bituminous Pavements

This stability investigation was started by the Bituminous Division of the Highway Materials Research Laboratory, Lexington, Kentucky during the month of October, 1944, and was completed the first of March 1945. The purpose of this investigation was to develop information on the design and control of asphalt pavements. The data presented may be used to compare mixes made from commercial aggregates with mixes containing local aggregates. It is believed that sufficient amount of reliable data is presented in this report to enable the design engineer to use the Marshall stability equipment and testing procedure to select the best available aggregate combination, gradation and bitumen content. This investigation includes a series of tests conducted on commercial aggregates now being used by the Department of Highways for bituminous pavements. The following commercial aggregates were included in this series of tests; river gravel and sand, limestone and sand, slag, and limestone. Three gradations were used for all aggregate combinations. These three gradations were selected to represent the minimum, average, and maximum percent passing each sieve size designated by the Department of Highways Class I, Type B, Specification