Civil Engineering Commons^™

Reducing Moisture Damage In Asphalt Mixes Using Recycled Waste Additives, Anthony John Boyes

Master's Theses

This thesis has determined that using fly ash as a mineral filler in asphalt pavements can help strengthen and reduce asphalt moisture damage. Also, dynamic shear rheometer tests show that these additives have a stiffening effect on asphalt binder. Moisture related damage is considered one of the main causes of asphalt pavement failure. As water infiltrates a layer of asphalt, it slowly strips away asphalt binder, weakening the aggregate/binder bond. This process, combined with the cyclic loading of traffic, can lead to several different types of asphalt failure including rutting, raveling, bleeding, and cracking. For several decades, research has been …

Development Of Approximating Functions To Model And Predict The Properties Of Fresh And Hardened Fly Ash-Based Geopolymer Concrete, Eleazar Ivan Diaz Loya

Doctoral Dissertations

The manuscript presented herein is based on the investigation of the mechanical properties of fly ash-based geopolymer concrete and their link to fly ash (FA) characteristics. A database of 32 FA samples was created. Each FA sample was analyzed in terms of chemical composition, crystallographic properties and particle size distribution. The mechanical performance of geopolymer concrete (GPC) made from each FA sample was evaluated in terms of density, setting time, compressive and flexural strength, static elastic modulus and Poisson's ratio. It is worth mentioning that the author has already published preliminary results of this study (Diaz and Allouche, 2010; Diaz …

Determination Of Ash Mixture Properties And Construction Of Test Embankment - Part B, Sungmin Yoon, Umashankar Balunaini, Monica Prezzi, Rodrigo Salgado, Nayyar Zia Siddiki

JTRP Technical Reports

Class F fly ash and bottom ash are solid residue byproducts produced by coal-burning plants. They are usually disposed off with a typical disposal rate of 80 % fly ash and 20 % bottom ash. To maximize the use of the coal ash, and thus significantly reduce the disposal problem that electric utility companies and our society in general face, the direct use of ponded or landfilled ash that is composed of high proportions of fly ash would be desirable. However, a general understanding of the behavior of high volume fly ash mixtures is needed. Although there have been investigations …

Technical Issues Related To The Use Of Fly Ash And Slag During Late-Fall (Low Temperature) Construction Season, Anand Krishnan, Jinesh K. Mehta, J. Olek, W. Jason Weiss

JTRP Technical Reports

The potential for scaling of concrete pavement containing fly ash is one of the durability concerns which imposes restrictions on the use of fly ash in paving applications in Indiana during the period of low temperatures (e.g., the late fall construction season). These restrictions increase the cost of paving projects, and occasionally, results in seasonal cement shortages. The objective of this study was to develop a better understanding of the scaling mechanism through a series of laboratory tests that focused on the role of material properties and length and temperature of curing in controlling scaling. Additionally, an attempt was made …

Complete Stress-Strain Characteristics Of High Performance Concrete, Insang Lee

Dissertations

High performance concrete (HPQ has recently become a widely used concrete construction material for modem buildings, bridges, and pavements, etc. To produce such a better quality of concrete, chemical and mineral admixtures such as fly ash, slag cement, and silica fume, ground granulated blast furnace slag, as well as air-entraining agents are commonly used in the field construction. It has been found that high perforinance concrete can improve the workability, ultimate strength and durability of the concrete. However, the enhancement of ductility in concrete, and concrete structures as a whole is still inconclusive and needs more research. The ductility can …

The Influence Of High Performance Matrices On Fracture Behavior Of Concrete, Pusit Lertwattanaruk

Dissertations

Modification of cement matrices by the addition of micro particle pozzolanic materials such as silica fume and fly ash is known to improve the strength of concrete, but its contributions to fracture behavior remains unclear. In this study, the influence of replacing cement by silica fume and fly ash on the cement matrix-coarse aggregate interfacial bond, compressive stress-strain behavior and fracture behavior of concrete is investigated.

While the linear elastic fracture mechanics (LEFM) concept is not appropriate for concrete, a nonlinear fracture model based on the load vs. load-line deflection and the load vs. crack-mouthopening displacement (CMOD) responses of the …

Building Embankments Of Fly/Bottom Ash Mixtures, Ahmed M.K. Karim, C. W. Lovell, Rodrigo Salgado

JTRP Technical Reports

This research investigates the engineering properties of mixtures of bottom ash and Class F fly ash relevant to their utilization in highway embankment construction. The research included ash samples from two major power plants in Indiana that disposed of their ash differently. The first power plant disposes of the bottom ash and fly ash separately and hence explicit mixtures were synthetically formed and tested. The second power plant disposes of the bottom ash and fly ash together in a common location and hence they become homogeneous samples for the research. Characterization of the ash included grain size analysis, specific gravity, …

Use Of Coal Combustion Residues And Foundry Sands In Flowable Fill, Subnahmanya T. Bhat, C. W. Lovell

JTRP Technical Reports

The purpose of the present study is to investigate the use of waste foundry sand in flowable fill. However, the concepts developed are applicable to flowable fills containing any type of sand. Even though the flowable fill is presently popular as a trench filling material, this study addresses a much broader perspective in order to be able to develop uses of this material in geotechnical applications. In this research, only green sands were taken. The fly ash used was class F type. Flowability, hardening characteristics and 28-day unconfined compressive strength are studied. A rational approach the mix design of flowable …

Utilization Of Fly Ash In Concrete, Chai Jaturapitakkul

Dissertations

Fly ash, a by-product of coal burning power plants, is produced in large quantities each year. It is commonly known that fly ash possesses pozzolanic behavior which can enhance the properties of concrete. Due to a lack of proper understanding on the formation of fly ash and its performance in concrete, the question of quality assurance has frequently been a major concern of engineers using fly ash in their construction projects. As a result, much fly ash is disposed of as waste material in landfills. Recent environmental concerns and a shortage of landfill space have rapidly escalated the disposal cost …

Influence Of Fly Ash Characteristics On Compressive Strength Of Mortar, Poorna Rajeswari Ratnaweera

Theses

Fly ash-cement mortar, constituting of fly ash, cement and sand, vary in strength characteristics from conventional cement sand mortar. Out of many parameters effecting the compressive strength characteristics of fly ash-cement mortar, four were investigated in this study. They are particle size and its distribution, weathering of fly ash, moisture content & water/cementitious ratio and mix proportioning.

Class F fly ashes from three different sources were used in this study. The particle size distribution and moisture content of fly ashes were investigated by standard ASTM methods. The unconfined compressive strength of mortar was obtained by testing 2"x2"x2" test cubes conforming …

Calcium Bentonite In Containment Structures, Ramnarayan K. Tirumala

Theses

Experiments were conducted on calcium bentonite from different sources to determine its suitability as a material for slurry wall. The emphasis was placed on cement-bentonite types of materials. A few tests were conducted on specimens consisting of soil-bentonite materials. Permeability, swelling potential, and immersion tests were conducted. Specimens were initially permeated with water to determine which variety of bentonite was most suitable and later with chemicals. In cement bentonite specimens, the effect of addition of blast furnace slag, fly ash, and sand were also studied. Addition of slag cement lowered the permeability value by an order of magnitude, and with …

Effects Of Fly Ash And Kiln Dust On The Compressive Strength Of Cement Mortar, Yitao Yu

Theses

Fly ash generated from coal-burning power plants has been an increasing problem to the utility company in terms of storage and disposal in compliance with the environmental regulations. Presently, fly ash has been widely used in the concrete mix. Research shows that fly ash can improve many properties of fresh and harden concrete. Landfill is another significant usage of fly ash. Usually, fly ash is stored in dry and weathered conditions. The properties of fly ashes from different sources and in different storage conditions are different.

In this research, the compressive strength of mortar containing cement replacement of Deep Hollow, …

Pozzolanic Admixtures In Concrete Mix, Ronghao Chen

Theses

Fly ash and condensed silica fume are two main mineral pozzolanic admixtures in portland cement concrete. The increasing use of the fly ash in concrete projects and concrete products during the past 3O years and condensed silica fume in several projects during the past 1O years indicates a greater acceptance of them as the mineral pozzolanic admixtures in concrete. Although the engineers are of some identical views in using these industrial byproducts in concrete projects, there are different views on how the behavior and utilization of fly ash con-crete and condensed silica fume concrete since the byproducts are not the …