Improving Literacy Rates for Students with Dyslexia in a Rural School District

This applied research study aimed to improve literacy rates for students identified as having dyslexic tendencies in the Lynn County School District. The need to improve literacy rates of students with dyslexia in the Reaching Reading Success Program was identified through Mississippi K-3 Assessment Support System data. Using the two elements found in the program evaluation, accurate identification of dyslexic students and multisensory interventions the study sought to improve the literacy rates for students with dyslexia in kindergarten. Assessment, survey, and interview data were used in this applied research study to determine success. The findings indicated early identification, multi-sensory remediation, and organizational learning does improve literacy rates for students with dyslexic characteristics in kindergarten

Clay Mineralogy and Soil Stabilization

This paper attempts to resolve a general concept of soil rheology from the standpoint of clay mineralogy, ion-exchange, properties of clay-water systems, and volume relationships existing between clay-water systems and granular structures. Both theory and experimental data are presented. In the experimental phase, synthetic soils of varying clay contents were prepared from carefully fractionated soil constituents. These were subjected to combined-stress analyses, tests for plasticity characteristics, and detenninations of other physical properties

Criteria for Design of Pavement Thicknesses, Kentucky Interstate Highways

The Kentucky Department of Highways, in 1946, sought a more systematic criteria and basis for designing the thickness of bituminous concrete pavements. The Research Division was authorized to pursue this work and to develop the criterion. These efforts were embodied in a report (1) to the Department, which offered a system of design based upon CBR\u27s and EWL\u27s. EWL\u27s were computed originally for a 10-yr. period but this practice was revised in 1954, to encompass 20-yr. traffic (more realistic with respect to average road life). Then, in 1957, the Department requested a re-evaluation of the criteria from the standpoint of experience and performance of pavements designed thereby. This re-study and recommendations was reported to the Department and to the Highway Research Board (2)(3). A copy of current design chart is shown on the following page (Fig. 20, ref. 2 and 3)

A Study of the Polishing Characteristics of Limestone and Sandstone Aggregates in Regard to Pavement Slipperiness

The coefficient of friction on dry highway surfaces regardless of stone composition and texture has in most cases been at least 0.6 or above. However, some of these same surfaces when lubricated by a small amount of water have given test results dangerously lower. Some interesting theoretical aspects of this situation are presented here along with results from a laboratory study of the fundamental factors affecting tractive friction. A machine is described for measuring the coefficient of friction between the plane surfaces of four-inch diameter stone specimens and a rubber annulus of slightly smaller diameter. Measurements were made both wet and dry on finely polished surfaces and on surfaces ground with 80 and 150 grit Carborundum. Tests were conducted under varying loads and speeds. A 60-degree reflectometer was used to evaluate texture and roughness of the plane surfaces. Reflectivity (gloss) values correlated significantly with wet friction values in the highly polished ranges. Tests were conducted on representative samples of four limestones and two sandstones. Coefficient of friction values of 0.01 and lower were measured on finely polished wet limestone surfaces. Sandstones subjected to the same polishing action averaged about 0.22 when wet. In another series of testing, the specimens were abraded with a coarse Carborundum grit, and the wet friction values were consistently between 0.6 and 0.7 for both limestones and sandstones. For further comparison a piece of plate glass was abraded with this same material, and it too measured within the above limits. Dry friction values remained fairly constant regardless of type of stone or texture. Test results reveal the tendency for fine grained particles bound in a matrix of similar hardness to polish more readily and to a greater extent than hard particles such as quartz bound in a soft matrix. Limestones, being typical of the former condition, polished easier than sands tones

Re-evaluation of the Kentucky Flexible Pavement Design Criterion

Prior to 1948, the criterion in Kentucky for designing the thickness of bituminous pavements was based upon a modified laboratory CBR and the 1942 curves developed by the California Department of Highways. In 1948, the Materials Research Laboratory reported: An Investigation of Field and Laboratory Methods for Evaluating Sub-grade Support in the Design of Highway Flexible Pavement. Included in that report as a recommended method of thickness design for use in Kentucky was a set of curves based upon an empirical relationship between minimum laboratory CBR and observed pavement performance. These five curves accounted for traffic groups up to 10,000,000 EWL\u27s. Since that time six additional curves have been included in the de sign charts for EWL groups up to 320,000,000. These additional curves were determined by extrapolation of the results from the 1948 study. Early in 1957, an evaluation of the design method was under taken. The basis for this re-evaluation was a statistical comparison of actual pavement performances with the designed life as anticipated or predicted by the design curves currently in use. On this basis, projects were selected, design records assembled, performances surveyed, and the data analyzed. Selected pavements which had been designed by the method developed in the 1948 study were checked for performance by visual survey, by roughness measurements, by measurements of rutting, by measurements of loaded-deflection with the Benkelman Beam, and by opening pavements for observation and sampling. Flexible base types studied included water bound macadam, bituminous concrete, granular dense graded aggregate and combinations. Laboratory evaluation on basis of bearing tests were made. The visual survey established a range of performance. Road roughness measurements were related to CBR but no attempt was made to draw design curves from this data since it could be greatly affected by factors not related to structural design. Pavements opened for inspection revealed permanent deformation in the upper layers of the system as well as intrusions of subgrade in waterbound base courses. An alternate method of design based on limiting deflection under load was developed from the Benkelman Beam measurements. Curves drawn from this data indicate a need for a slightly greater thickness than provided by the 1948 curves

Ten Rural Highway Base Stabilization Projects

During the last week o£ September, 1956, the Division of Rural Highways requested assistance from the Research Division in conducting a series of ten experimental base stabilization projects which were to be geared more-or-less to a practical rural roads development program in which existing soils and local granular materials might be most advantageously treated and stabilized to provide fairly low cost base courses and surfaces, adequate for light rural traffic. The idea of actually constructing a base and bituminous surface for this type of road would represent a refinement over the traditional traffic-bound base type of construction which usually serves as a preliminary to light bituminous surfacing. While the traffic-bound type of construction has been used effectively in the past, there seems to be an inherent impatience on the part of property owners and general public to get on to the bituminous surfacing stage before the traffic-bound base has fully stabilized. In several such instances it has been necessary to add extra surfacing within a year or so, or else to revert to the traffic-bound stage again and start over

Concrete, Bridge Decks: Deterioration, Coatings and Repairs

This report is not wholly a culmination of a planned or programmed research project. It is a historical account of damage sustained by both new and old concrete bridge-decks -- through freeze-thaw, salt action, etc, -- and of some expedient repairs which have been effected. The problem of durability in concrete bridge-decks has become increasingly critical during the past ten years or so and is now a major concern to highway engineers throughout the northern tier of states. While there is not yet a concerted agreement in regard to the cause of the trouble, relief is being sought through improved construction practices, air-entrainment, and protective coatings of various kinds. Similarly, relief from perpetual maintenance or complete replacement of existing bridge decks is being sought through improved methods for making repairs. The performance of individual slabs in a deck is sometimes markedly different from that of a nearby slab; and, even within a particular slab, only one corner or one end may be affected. This signifies poor concreting practices. The concrete sustaining damage was undoubtedly over-watered, over-worked, de-aired, and segregated. The proper placement of deck concrete is perhaps the more serious aspect of the problem than the repair, because improper placement automatically incurs a premature maintenance liability. Of course, as the need for repairs arises in due time, reliable methods of repair should be employed. It is in this latter respect that the repair experiences recorded in this report are expected to be the most fruitful. None of the damaged decks which have been observed thus far has shown any evidence of overloading by traffic (adjudged by the absence of any checker-board crack-pattern on the underneath side of the deck); the trouble seems to be attributable almost entirely to weathering; and the weathering invariably seeks out and attacks the poorest concrete often revealing the mistakes made by the workmen and their attempts to hide them. Improper drainage of the deck and gutter can be one of the contributing factors to damage. Even slabs and gutters sometimes have bird-baths in them. Cinders, sand, road-debris, and snow sometimes impound water and prevent drying. Such areas are exposed to water and moisture beyond their normal time and damage is often associated with these conditions

The Safety Barrier Dilemma

Ran-off-the-road fatal accidents currently account for approximately 65 percent of all freeway fatalities (1). Accordingly, ever-increasing emphasis has been given to the development of effective safety barrier systems, from guardrails to earth berms to median barriers to energy absorbing barriers and mires. However, highway designers have also recognized that safety barriers are hazards in themselves, misfits in the highway environment, and that they are items to be eliminated wherever possible. In a study of fatal accidents on the Interstate Highway System, it was found that fixed object collisions have been the leading source of fatalities, accounting for 43 percent of the 1968-1969 fatal accidents (2). Ironically, guardrails were found to be the most frequent objects struck first -- accounting for 31 percent of the total. Furthermore, this same study estimates that, excluding non-interstate and secondary urban roads, 6,300 miles of guardrail were constructed on public roads in 1969. Statistics such as these illustrate the risks facing today\u27s drivers on the Interstate Highway System. Until a major modification is made that produces a significant reduction in such risks, less mobility (through travel restrictions) will be required to produce a significant reduction in fatalities per year (3)

Traffic Control for Maintenance on High-Speed Highways

Observations were first made at lane closures on interstate highways where yellow warning signs were erected routinely in conjunction with contract work. Later data provided direct comparison between new yellow and new orange signs. One sign scheme was used throughout the study. Driver obedience improved when new signs of either color were used; this finding implies that signs should always be maintained in good condition. Orange signs were slightly more effective than yellow signs in reducing traffic conflicts and merges near the traffic cones. Results of the study tend to support the adoption of orange as the standard color for signing construction and maintenance sites. However, differences between the two colors were rather small. Driver preference polls supported the orange signs more strongly. A degree of driver insensitivity toward signing was shown. In general, variables such as short sight distances, high volumes, poor condition of signs, and driver insensitivity produced unsafe situations at lane closures. However, the scope of the study did not permit observations at sufficient sites and(or) at sufficient times to serve as a definitive exploration of such variables as weather, terrain, vertical and horizontal alignment, or level of service