Study of Proposed Specifications for Bituminous Coated Corrugated Metal Pipe

On February 27 and 28, the author visited the Research Laboratories of the American Rolling Mills Company at Middletown, Ohio. The purpose of the visit was to investigate the technique and background of the new specifications for bituminous coated corrugated metal pipe as proposed by Armco with a view to changing the Kentucky Specifications (throughout this report proposed specifications will refer to the specifications recommended by the American Rolling Mills Company). It is a rather evident fact, but the author wishes to point out that the short visit could furnish only an indication rather than a positive solution to the problem

Excerpts from: A Study of the Relationship between Subgrade California Bearing Ratios and Pumping of Rigid Pavements

The purpose of this investigation was to determine the relationship between the pumping of rigid pavements and the modified California Bearing Ratio of the subgrade soil, beneath the pavement. The ultimate objective is a design criteria for eliminating or minimizing in the most economical way, pumping of rigid pavements in Kentucky

Porous Backfill

Until the late 1930\u27s, the accepted practice for the construction of drainage installation included the use of a large, approximately No. 2 size, aggregate as porous backfill. However, a lage number of drains ceased to function as result of clogging or silting *, and many highway departments practically eliminated sub-surface and intercepting drainage. The following report summarizes some of the more important studies that have dealt with filter (backfill material) to be used in drainage construction. The scope of it is limited, dealing primarily with the questions of proper gradation. At present Kentucky Specifications (1) require that the gradations of the aggregate for backfill over pipe underdrains be as specified for Class \u27A\u27 concrete , (page 462), that is No. 6 size coarse aggregate (No. 8 to 1-1/2 ). For stone underdrains, it is required (page 408) that a No. 2 coarse aggregate be used (1-1/2 to 3 )

A Study of the Relationship between Sub-grade California Bearing Ratios and Pumping of Rigid Pavements

The purpose of this investigation was to determine the relationship between the pumping of rigid pavements and the modified California Bearing Ratio of the subgrade soil, beneath the pavement. The ultimate objective is a design criteria for eliminating or minimizing in the most economical way, pumping of rigid pavements in Kentucky

Investigation of Field and Laboratory Methods for Evaluating Subgrade Support in the Design of Highway Flexible Pavements

Four different methods of evaluating subgrade support under flexible pavements were studied: (1) Field CBR; (2) North Dakota Cone; (3) Bearing Plates; and (4) Laboratory CBR. Approximately 435 miles of flexible pavements in Kentucky were represented. The roads were selected so as to give a wide range in conditions of traffic, soil areas, and design. A total of 185 locations were investigated, and 338 cone tests, 291 field CBR\u27s, and 117 series of plate tests were conducted. There were 178 subgrade samples for which the laboratory CBR test was conducted. Undisturbed samples for future triaxial tests were obtained at 21 locations. Subgrade moisture variation was considered. Traffic was determined by loadometer surveys and use of traffic flow maps. For the traffic imposed, adequacy of the designs -- as indicated by the presence or absence of base failures was evaluated from the standpoint of subgrade support measured by the four methods of test. Comparisons among the various methods of test in determining the subgrade support were made. The ultimate objective is a design criteria for flexible pavements in Kentucky

Changes in Biomedical and Physical Correlates in Behavioral Weight Loss with Retarded Youths

Seventeen trainable mentally retarded youths were assigned to either a behavior therapy (N = 6), an obese wait·list control group (N = 5) or a normal weight control group (N = 6). The behavior therapy subjects lost significantly more weight than the two control groups who gained weight. The behavior therapy subjects achieved significant reductions in tricep skin· fold thickness, abdominal circumferences, and diastolic blood pressure measures by the end of the 21·week treatment program. The advantages of using multiple dependent measures is discussed

Binocular vision in amblyopia : structure, suppression and plasticity

The amblyopic visual system was once considered to be structurally monocular. However, it now evident that the capacity for binocular vision is present in many observers with amblyopia. This has led to new techniques for quantifying suppression that have provided insights into the relationship between suppression and the monocular and binocular visual deficits experienced by amblyopes. Furthermore, new treatments are emerging that directly target suppressive interactions within the visual cortex and, on the basis of initial data, appear to improve both binocular and monocular visual function, even in adults with amblyopia. The aim of this review is to provide an overview of recent studies that have investigated the structure, measurement and treatment of binocular vision in observers with strabismic, anisometropic and mixed amblyopia