Pavement Surveys

The major considerations in the evaluation of a slab\u27s condition, where surface defects exist, are the number of defects, their type and size. It is possible for a slab to contain a large number of surface intrusions without being appreciably damaged, if the impairments are all very small. On the other hand, only a few very large defects would be very damaging. Certainly, the most satisfactory condition would be the complete absence of blemishes. In the surveys which have been made since the beginning of these pavement investigations, soil holes, chert pop-outs, shale pitting, trash imbedments and cracks have comprised nearly one hundred percent of the defects observed. The defects are listed in declining order of damaging effect to the slabs inspected. By far, the most prevalent types of defects are soil holes and chert pop-outs. These surveys have been made, insofar as possible, to include all defects which were one-half inch or more in diameter and all transverse cracks

Cold-Weather Concreting

In order to successfully place concrete in cold weather, certain established requirements must be met. The concrete must not be allowed to freeze, it must not be overheated by artificial means in an attempt to protect it from the cold, and proper curing conditions must be maintained during the period of protection to insure sufficient moisture for the cement to hydrate. Generally, temperatures of not less than 50°F and not more than 90°F are satisfactory. These temperatures must be maintained long enough for the concrete to develop sufficient strength to withstand freezing temperatures and to support the loads. Generally, concretes made with other than Type III cement should be maintained at temperatures above freezing for at least six days, and concretes made with Type III cement should be maintained at temperatures above freezing for at least four days

An Evaluation and Summary of the 16-Year Performance of a Concrete Test Pavement

Presented herein are a summary and evaluation of the performance of a reinforced concrete section of U.S. 27 in north central Kentucky which has been in existence since the summer of 1941. The pavement, totaling 7.89 miles, was constructed in 10 experimental test sections, as shown on the layout map in Figure 1. Five blends of cement, containing normal portland, natural, and two additives, were used with two types of coarse aggregate, limestone and gravel. Since the construction of the pavement in the summer of 1941, several reports and memoranda have been released dealing with various aspects of the over-all study: Test results on cores taken in 1941, KDH, April, 1942. Results of freezing and thawing beams made in 1941, KDH, August, 1943. Supplement to August, 1943, freeze and thaw report, KDH, November, 1944. Summary Report of Concrete Investigations in Research Projects, HMRL, December, 1945. Experiments with Air-Entrainment in Cement Concrete, Engineering Experiment Station, Bulletin No. 5, Sept. 1947. (The test sections are referred to as Project C-1 in this bulletin.) Inspection Report, HMRL, June, 1953. Inspection Report, HMRL, June, 1957

Rockcastle (Pottsville) Conglomerate Sand Evaluation in Portland Cement Concrete

In order to analyze the concrete making properties of a processed Pottsville Conglomerate Sand from Rockcastle County, Kentucky, several batches of portland cement concrete were made. Standard mixing control, strength, and durability tests as well as a short cut test to detect excessive expansion during curing were performed on the concrete. Control specimens were made utilizing an Ohio River Sand, typical for this area, as the fine aggregate. This sand which was acceptable by Kentucky Highway Department Specifications was produced by the Nugent Sand Company of Louisville, Kentucky. The sand was submitted for evaluation in this manner by the State Geologist. The standard physical properties tests were made by his office prior to the submission, and the sand was found to be satisfactory in accordance with those tests

The Use of Epoxy Resin for Sealing Cracks in a Reinforced Concrete Bridge

In the summer of 1958, a special formulation of epoxy resin was used to seal hairline cracks in the safety walks of the Levisa-Fork bridge at Paintsville, Kentucky. This bridge, a reinforced concrete box girder-type, Fig. 1, developed fine cracks soon after the falsework was removed. The cracks which were typically like those in Figs. 2 and 3, occurred in two areas, each extending about 30 ft. on either side of the center piers. They were through the full depth of the slab and ranged from about .005 in. to .031 in. in width. In all, there were 55 cracks averaging 3 ft. in length, making a total of 165 lineal ft. of cracks to be sealed. After conducting laboratory investigations to test the flexural and bonding strengths and penetrating ability of the epoxy formulation, Reliance Relcote 60 , Figs. 4 and 5, it was concluded that this material would be suitable for sealing cracks in structural concrete. The resin\u27s strength and resistance to water, weather, and corrosion were considered sufficient to protect the concrete and steel exposed by the cracks

Investigation of Concrete Pavement US-60 Between Versailles and Frankfort

A complete survey of the above project was made between April 27, and May 13, of this year to deter mine the condition of the pavement after the second winter of service. The data from this survey include all of the approximately ten miles of four-lane highway, Tables I and II; all of the cross-overs, Table III; and the ramps and connecting lanes in the interchanges, Tables IV and V. Table VI covers the areas where several surveys have been conducted and Table VII is a breakdown of the total defects by type for the whole project. These tables are summaries of the condition of each slab or area on the project at present, and can be compared to previously prepared tables in reports on the subject pavement dated February 15, 1960, May 12, 1960, and June 17, 1960

17-year Report on the Owensboro-Hartford Co-operative Investigation of Joint Spacing in Concrete Pavements

In 1940, the Kentucky Department of Highways constructed an experimental concrete pavement which was one of a group of six built in co-operation with the Bureau of Public Roads by the States of Minnesota, California, Kentucky, Michigan, Missouri and Oregon. The purpose of these projects was to study and evaluate the performance of such pavements over a period of years with specific regard to types of joints and spacings. The Kentucky project, consisting of 6.27 miles, was constructed in Daviess County, beginning approximately 6 miles south of Owensboro on US Route 231 (formerly Ky. Route 71). This report is a continuation of the 1940 joint-spacing and pavement performance study. A complete discussion of the original scope, purpose, and early performance of this project has been given in previous reports (l, 2, 3, and 4). The present report is essentially a 17-yr. performance report but includes some data obtained through 1958. Subgrade, traffic, riding quality, and over-all condition data are provided

An Evaluation of Four Retarding Admixtures in Structural Concrete

Early in 1960, the Construction Division was becoming quite concerned with the growing problem of obtaining satisfactorily smooth reinforced concrete bridge decks. Increasing areas of new decks were not measuring up to requirements when checked with a straight-edge, and rough-riding surfaces were resulting even after corrective grinding. It appeared that, on large pours, perhaps more time for placing and finishing was needed; this was so particularly on hot, windy days when ambient conditions would cause the concrete to set more rapidly. A proposed method of providing more working time was to use retarding admixtures to slow the setting time of the concrete