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Concrete

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Articles 541 - 553 of 553

Full-Text Articles in Engineering

Low-Void Concrete Mixtures, Assaf S. Rahal, James H. Havens Dec 1978

Low-Void Concrete Mixtures, Assaf S. Rahal, James H. Havens

Kentucky Transportation Center Research Report

The purpose of this study was to modify concrete mix-design formulas to supplant all water over and above that needed for hydration with a non-evaporable liquid material and(or) a super-water-reducer or plasticizer -- thus producing a low-void concrete. A water-cement ratio of 0.244 - 0.30 was presumed minimal for hydration of the cement. Several polymeric materials, asphalts, oils, and superplasticizers were used. Success was achieved with two latexes, one epoxy, and several superplasticizers. The use of these materials in concrete resulted in improved strength, reduction of air voids and permeability, and enhancement of resistance to corrosive chloride salts.


An Investigation Of Low Cylinder-Strengths (District 6), Assaf S. Rahal Aug 1977

An Investigation Of Low Cylinder-Strengths (District 6), Assaf S. Rahal

Kentucky Transportation Center Research Report

District 6 has had a lingering problem of low cylinder-strengths. This report describes, in detail, an ensuing investigation which incorporated the use of identical materials of concretes used in District 6 and analyses of cylinder data, in situ concrete cores, and laboratory mixtures. The investigation revealed that a high percent of the in situ concrete is sound and reliable, and that aggregate type and (or) air content were not the cause for the low cylinder-strengths. The quality of making, storing, and curing the cylinders were the reasons for low-strength.


Freeze-And-Thaw Of Concretes And Aggregates, James H. Havens, Robert C. Deen Jun 1976

Freeze-And-Thaw Of Concretes And Aggregates, James H. Havens, Robert C. Deen

Kentucky Transportation Center Research Report

This report summarizes several years of research relating to damage to concrete and aggregates undergoing freezing and thawing. Basic principles involving freezing and attendant pressures are considered. Application of these principles to the evaluation of concrete was accomplished in experiments on concrete having low and high air contents. The effects of air entrainment upon freeze-thaw resistance were demonstrated.

Freeze-thaw characteristics of saturated aggregates relative to physical properties such as porosity, absorption, and bulk specific gravity were studied by submerging individual particles in pre-chilled mercury. Pressures associated with popouts in concrete were monitored and are presented along with accompanying theoretical considerations.


Voidless Concrete Mixtures For Bridge Decks, Assaf S. Rahal Dec 1974

Voidless Concrete Mixtures For Bridge Decks, Assaf S. Rahal

Kentucky Transportation Center Research Report

The purpose of this study was to modify concrete mix-design formulas to supplant all water over and above that needed for hydration with a non-evaporable material -- thus producing a no-void concrete. It was adjudged that a water-cement ratio of 0.244 would be practical for hydration of the cement. Several polymeric materials, asphalts, and oils were used to replace the excess mixing water. Success was achieved using two latexes and one epoxy. The use of these materials in concrete resulted in improved strength, reduction of air voids and permeability, and enhancement of resistance to corrosive chloride salts.


An Evaluation Of In-Stream Structures Designed To Provide Fish Habitat, Charles H. Call Jr. May 1974

An Evaluation Of In-Stream Structures Designed To Provide Fish Habitat, Charles H. Call Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In-stream concrete structures were studied through model tests and river tests. The model studies indicated that four designs provided good habitat in the model stream. These structures were the inverted weir, the "V" structure, the slab with legs and the cylinder. Through the river studies it was determined that these structures did not influence enough of the total river area to be effective in providing good fish habitat. Also an appreciable amount of yearly maintenance would be required to free the structures from silting in, debris, and vandalism. The slab with legs was the only promising structure.


Construction, Protection And Maintenance Of Concrete Bridge Decks, Ronald D. Hughes, James H. Havens Aug 1972

Construction, Protection And Maintenance Of Concrete Bridge Decks, Ronald D. Hughes, James H. Havens

Kentucky Transportation Center Research Report

This report presents an historical account of deterioration in reinforced concrete bridge decks. Preventative maintenance treatments to both new and in-service decks are discussed. Repair methods are included. The major forms of deterioration are listed and causative mechanisms are discussed. Potential design and construction remedies are presented for consideration.


Durability Of Traffic Paint On Portland Cement Concrete Pavements, Assaf S. Rahal Nov 1971

Durability Of Traffic Paint On Portland Cement Concrete Pavements, Assaf S. Rahal

Kentucky Transportation Center Research Report

Performance of a series of transverse lines applied to a relatively new concrete pavement, utilizing primes and pretreatments, is reported. The report includes descriptions of the location of test lines and types of paint and pretreatments, performance histories, and analysis of results. Chlorinated rubber, epoxy, and urethane paints were the most durable. Neither pretreatment nor the use of primes significantly increased durability.


Concrete In Dairies, D Roger Buchanan Jan 1968

Concrete In Dairies, D Roger Buchanan

Journal of the Department of Agriculture, Western Australia, Series 4

PRIME requirements for exposed concrete surfaces in dairies are that they should be easily cleansed and should not deteriorate in contact with milk and milk products.

In milking stalls, animal races and on loading platforms hardwearing surfaces which offer good foothold are also necessary.


The Effects Of An Epoxy (Epocast 546) Upon The Tensile And Compressive Properties Of Portland Cement Concrete, Alvy C. Jackson Jun 1963

The Effects Of An Epoxy (Epocast 546) Upon The Tensile And Compressive Properties Of Portland Cement Concrete, Alvy C. Jackson

Civil Engineering ETDs

Although the behavioral pattern of plain concrete in compression is fairly consistent, its tensile properties leave much to be desired. The laboratory investigation described here was an attempt to increase the tensile property of plain concrete by adding an epoxy resin compound to the mixture. The investigation included tests for both compressive and tensile strengths of the mixtures that were considered. The compressive strength tests were included to determine what effect, if any, the attempt to increase the tensile property had on compressive strength.


Concrete Color Variations Observed In Specimens Made From 12 Type 1 Portland Cements, Milton Evans Jr. Nov 1961

Concrete Color Variations Observed In Specimens Made From 12 Type 1 Portland Cements, Milton Evans Jr.

Kentucky Transportation Center Research Report

No abstract provided.


Design Of Plain Concrete Runways And Taxiways Of A Class 4 Airport, Erkmen Erkmen Jan 1959

Design Of Plain Concrete Runways And Taxiways Of A Class 4 Airport, Erkmen Erkmen

Masters Theses

"This thesis is a study for determining the most economical design for the pavements of Adana Airport. It is a study of redesigning efficient and safe runways and necessary taxiways for a future service life of thirty years.

Adana is Turkey’s 6th largest city. It is a growing city. An airport in Adana also serves tor industrial purposes, serves for transcontinental airway systems. In Adana there is an important Nato Base and in a future war such an airport can be used for military purposes. For these reasons, it was decided to construct a class 4 airport* for the city. …


A Study Of The Effect Of Blended Coarse Aggregate On Air-Entrained Concrete Progress Report 3, S. T. Collier Nov 1949

A Study Of The Effect Of Blended Coarse Aggregate On Air-Entrained Concrete Progress Report 3, S. T. Collier

Kentucky Transportation Center Research Report

The purpose of this investigetion was to study the durability characteristics of a river gravel, used as coarse aggregate for concrete, with respect to four major fractions separated in accordance to their general mineralogical classification. This aggregate was from the same stock of Ohio River gravel that was used in earlier phases of this Project reported in 1947.

Since this gravel consisted of several rock types varying in mineralogic constituents, it was conceivable that poor performance could possibly be attributed to some undesirable fraction or fractions, rather than to the aggregate as a whole. The separation of this aggregate was …


Study Of The Effect Of Blended Coarse Aggregate On Air Entrained Concrete Second Progress Report, Kentucky Highway Materials Research Laboratory May 1947

Study Of The Effect Of Blended Coarse Aggregate On Air Entrained Concrete Second Progress Report, Kentucky Highway Materials Research Laboratory

Kentucky Transportation Center Research 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 …