Engineering Commons^™

Creep Characteristics Of Thin Prestressed Concrete Slabs, Wayne F. Alch

Masters Theses

"Prestressed concrete as a structural material is finding wider usage in the United States today. Until recently, economic factors have precluded the use of prestressed concrete in this country, while Europe became the leader in discovering new uses and applications in construction for the material. As new methods are developed in this country, more engineers and contractors are discovering that prestressed concrete is, in many ways, far superior to plain or reinforced concrete. In line with this awakening the Missouri Highway Department is carrying on research to determine the feasibility of prestressed concrete for highway slabs. This study is a …

Investigation Of Length Changes In Prestressed Concrete Slabs With Outside Exposures, John Best

Masters Theses

"In general, pavements may be classed as being either rigid or flexible. The term “rigid pavement”, as commonly used in the United States, is applied only to wearing surfaces constructed of portland-cement concrete. All other types of pavements are classed as “flexible”. A pavement constructed of portland-cement concrete is assumed to possess considerable flexural strength which will permit it to act as a beam and allow it to bridge any minor irregularities which may occur in the base on which it rests, hence the term “rigid”….

In view of the experience and information gathered in over 50 years of road …

The Magnitude And Directions Of Strains And Stresses In Edge Loaded Concrete Slabs, William M. Baldwin

Masters Theses

"The concrete industry in the United States represents one of the fastest growing segments of the national economy. Many reasons for this may be given, among which are, the durability of concrete structures, the local availability of a large portion of the materials used in concrete, and its wide range of adaptability to the designs of engineers and architects.

One of the most recent changes in concrete usage is the change from reinforced concrete to prestressed concrete. The term prestressed as used herein refers to any type of reinforced concrete in which the reinforcing material has a stress prior to …

Investigation Of Length Changes And Warping In Thin Prestressed Pavements, Wilbur D. Stites

Masters Theses

"The present growth of the American highway system presents a staggering problem to the highway designer. The increased and urgent demand for more highways, capable of accommodating traffic loads that are constantly increasing, combined with the increased construction cost of highways, behooves the present day highway designer to envision future highway problems that will arise. These future problems are numerous and complex; however, it seems the primary problem is the selection of a surfacing material that will withstand projected traffic loads with a maximum economy of construction and future maintenance costs. Concrete at the present time is the most satisfactory …

Filter Materials For Emergency Use In Diatomite Type Water Filters, Robert Wassell Mcleane

Masters Theses

"A completely different type of filter, using diatomaceous earth as the filter media, had been in use for many years for filtration of industrial liquids, however, the use of diatomaceous earth for water filtration purposes had been discouraged due to the rapid clogging of the filter material. "As late as 1930 it was reported that the very excellence of filtration with diatomite prevented its extensive use in water filtration except where complete elimination of bacteria and suspended matter is essential.”

Diatomaceous earth, however, seemed to exhibit the general properties the research groups were seeking; in the refined state it exhibited …

Physical Properties Of Concrete At Early Ages, Curtis E. Weddle Jr.

Masters Theses

"The introduction of the motor vehicle and the subsequent rapid expansion of the highway systems of the United States have brought with them many problems.

The Civil Engineer, in his attempts to provide adequate safe avenues of travel for the populace, has been faced with many problems. Handicapped by the need for speed in design and lack of information of the trends in motor vehicle design, the engineer has been forced at times to utilize design methods inconsistent with good engineering practices.

Of the many types of pavement sections which have been designed in an effort to provide structurally and …

A Determination Of The Sonic Modulus Of Early Age Concrete, William Dale Nelson

Masters Theses

"The problem which the writer is analyzing in this thesis was suggested by Professor E. W. Carlton of the Civil Engineering Department. It is a determination, by use of sonic testing equipment, of the growth in the sonic modulus of early age concrete.

Since 1938 when T. C. Powers published his paper, "Measuring Young's Modulus of Elasticity by Means of Sonic Vibrations", in the proceedings of the American Society of Testing Materials, Vol. 38, Part II, a great deal of work has been done on the applications of sonic testing of concrete. It began a new era in concrete testing, …

Investigation Of Plastic Deformation In Prestressed Concrete Slabs From Long Time Loading, Joe B. Roberts

Masters Theses

"It is the purpose of this research to investigate the creep in a thin concrete slab under a long-time prestress load with the compressive load being applied to the edge of the slab through a bearing plate of small dimensions.

Seven plain concrete slabs, 3' x 4' x 4", approximately one year old, made of normal cement and approved aggregate were subjected to the following loading conditions: (1) Three slabs loaded at the center of the greater dimension with a prestress load or 20,000 pounds applied over an area of eight square inches, (2) Three slabs loaded symmetrically at six …

Physical Properties Of Concrete At Early Ages, Karl H. Dunn

Masters Theses

"There are well over 100,000 miles of concrete pavements existing today on our United States highway system. The development of these pavements during the first half of this century has been a process of learning from construction applications and mistakes. However, the unexpected increase in traffic load has brought highway designers to experiment with relatively new types and designs of concrete pavement construction.

Some designers, in an effort to reduce temperature warping stresses, have used short slabs 10 to 15 feet in length, generally unreinforced. Another type of construction is the definitely jointed slabs, the slabs being from 20 to …

The Correlation Of Kelly Ball Penetration Readings With Standard Slump Cone Readings For Concrete Made From Missouri Aggregates, James Claude Rives

Masters Theses

"The ASTM standard slump test as set forth in ASTM Designation: C143-52, has been used for many years in concrete construction tor measuring the consistency of plastic concrete. Slump tests taken in the laboratory are considered reasonably accurate; however, there are numerous disadvantages in performing these tests in the field; the most serious being the time required to make a test on pavement work. The standard slump cone method is also subject to personal differences in sampling, rigidity and smoothness of base, dampening the apparatus, filling the cone, rodding, raising the cone, freedom from jarring and selection of point to …

Development Of Rating Curves For Concrete Rebound Hammer On Concrete Specimens From Local Aggregates, Rolla Smith Lush

Masters Theses

"Frequently engineers find it imperative to determine the compressive strength of concrete as it exists in a structure. There are two methods of making this determination, either by a destructive or a non-destructive test. The destructive test has the disadvantage of being costly, time consuming, and detrimental to the appearance of the concrete surface. The non-destructive, pulse-velocity, sonic measuring devices used to determine the compressive strength of concrete in the field also have the disadvantage of high cost due to the large initial cost of the equipment.

A relatively new non-destructive testing device has been developed which may replace the …

A Comparative Determination Of Weld Shearing Values In Welded Wire Reinforcement Fabric, Ernest Charles Kobs

Masters Theses

"At the suggestion of Professor E. W. Carlton, Chairman, Civil Engineering Department, Missouri School of Mines and Metallurgy, the author selected as subject for research thesis, “A Comparative Determination of Weld Shear Values in Welded Wire Reinforcement Fabric”.

In 1948, the Wire Reinforcement Institute initiated a research program to measure the actual stresses, including weld shear stresses, that occur in Welded Wire Fabric when used as reinforcement in a concrete slab. A great majority of this research was under the supervision of Professor Carlton.

The results of these investigations indicated a wide variation in strength of welds. As a means …