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Kim J.,Center for Advanced Infrastructure and Transportation | An J.,University of Central Florida | Nam B.H.,University of Central Florida | Tasneem K.M.,University of Central Florida
Road Materials and Pavement Design | Year: 2015

The main focus of this study is the characterisation of the municipal solid waste incineration (MSWI) ashes and their influence on engineering properties of cement paste when part of Portland cement is replaced with ground MSWI ashes. Petrographic examinations were performed in order to identify chemical composition of ashes and to determine their contents. To evaluate the main side effect of ashes when used in cement, the creation of network of bubbles due to the presence of aluminium, ashes, and aluminium powder were submerged in high pH solution and the evolution of hydrogen gas was measured. Cement paste cylinders were cast with various amounts of mineral additions and their strength and durability were investigated. Analysis on the measured data demonstrated that the use of ashes as cement replacement has both beneficial and detrimental effects on the strength and durability caused by the filler effect and hydrogen gas development, respectively. © 2015 Taylor & Francis

Kim J.,Center for Advanced Infrastructure and Transportation | Nam B.H.,University of Central Florida | Al Muhit B.A.,University of Central Florida | Tasneem K.M.,University of Central Florida | An J.,University of Central Florida
Magazine of Concrete Research | Year: 2015

In this paper, municipal solid waste incineration (MSWI) bottom ash was characterised before and after chemica treatment and the effect of ash addition on the performance of concrete as a partial replacement of fine aggregate was evaluated. The chemical treatment aimed to eliminate the side effect of MSWI ash - the creation of a network of bubbles - which can eventually lead to a significant reduction of the overall performance of concrete Petrographic examinations, energy dispersive X-ray spectroscopy and X-ray diffraction, were carried out to chemically characterise the MSWI bottom ash. The mechanical performance of the ash-combined concrete was evaluated by measuring its compressive strength. Analysis of the measured data demonstrates that the chemica treatment successfully transformed metallic aluminium in the ash into a stable form and hence expansion of the concrete due to hydrogen gas evolution was no longer detected in the concrete containing treated ash Consequently, compared with specimens with untreated ash, concrete specimens with treated bottom ash showed improved performance.

Nam B.H.,University of Central Florida | Behring Z.R.,District 4 | Kim J.,Center for Advanced Infrastructure and Transportation | Chopra M.,University of Central Florida | And 2 more authors.
Journal of Testing and Evaluation | Year: 2015

Recycled concrete aggregate (RCA) is often used as a replacement for virgin aggregate in road foundations (base course), embankments, hot-mix asphalt, and Portland cement concrete. However, the use of RCA in exfiltration drainage systems, such as French drains, is still uncommon. The primary concerns with using RCA as drainage media are excessive fines and calcite precipitation that can cause a reduction in permeability performance. This study investigates the potential benefits of RCA as drainage material. This paper presents and discusses: (1) the results of a nationwide survey on current practices and policies, (2) physical and chemical properties, (3) effective fine-removing methods, (4) re-cementation potential, (4) permeability (under varied fine content), and (5) long-term drainage performance of RCA as drainage material. Test results indicate that RCA No. 4 gradation does not restrict the flow of water, but the RCA fines being generated during aggregate handling process (e.g., stockpiling, placing and transporting) may cause clogging buildup over time. Copyright © 2014 ASTM International.

Bennert T.,Center for Advanced Infrastructure and Transportation | Cooley Jr. L.A.,Burns Cooley Dennis Inc. | Ericson C.,Rutgers University | Zavery Z.,POD 34
Transportation Research Record | Year: 2011

This study evaluated the asphalt mixture performance of various gravel and crushed stone sources with different levels of crushed face counts as determined by ASTM D5821. Coarse aggregate angularity and texture were also evaluated with AASHTO T326 and aggregate imaging system testing. Each of the asphalt mixtures designed and tested used three asphalt binders: (a) neat PG 64-22, (b) polymer-modified PG 64-22 meeting New York State Department of Transportation (New York State DOT) elastic recovery specifications, and (c) polymer-modified PG 76-22. The permanent deformation properties of the different asphalt mixtures were measured with the asphalt pavement analyzer (AASHTO TP63) and the asphalt mixture performance tester (AASHTO TP79) with confining pressure applied to the specimens. Aggregate testing showed that ASTM D5821 correlated poorly with both AASHTO T326 and the aggregate imaging system. Situations also occurred in which aggregates had identical crushed counts but different levels of uncompacted void contents. The asphalt mixture performance tester that used confining pressure correlated well with the uncompacted voids content results of AASHTO T326. However, stresses applied in the asphalt pavement analyzer did not sufficiently mobilize the asphalt mixtures to allow differences in aggregate angularity to be clearly noted. Both asphalt tests were sensitive to asphalt binder high-temperature stiffness as determined by AASHTO TP70. Statistical analysis of the data resulted in a table that allows the New York State DOT to use aggregate angularity (as determined by AASHTO T326) and nonrecoverable creep compliance (as determined by AASHTO TP70) interchangeably to ensure that hot-mix asphalt (HMA) blends containing gravel aggregate perform as well as HMA blends containing crushed-stone aggregate.

Kim J.,Center for Advanced Infrastructure and Transportation | Gucunski N.,Rutgers University | Dinh K.,Center for Advanced Infrastructure and Transportation | Duong T.H.,Center for Advanced Infrastructure and Transportation
Geotechnical and Structural Engineering Congress 2016 - Proceedings of the Joint Geotechnical and Structural Engineering Congress 2016 | Year: 2016

This paper presents a novel method for presenting the concrete bridge deck condition assessed by multiple nondestructive evaluation (NDE) technologies using a three-dimensional visualization program, NDEFuse. Six types of NDE data can be visualized: (1) impact-echo data for mapping and describing the depth and severity level of concrete delamination, (2) ultrasonic surface wave data for concrete quality (elastic modulus) assessment, (3) electrical resistivity for the description of corrosive environment and estimate of the corrosion rate of steel reinforcement, (4) mapping of top rebar layer and (5) ground penetrating radar condition assessment data, and (6) high-resolution deck surface image for documenting signs of deterioration, previous repairs, and surface wear. The 3D visualization platform integrates and visualizes the six NDE results in a very intuitive way. Correlations between the different types of NDE survey results were established visually in a 3D space utilizing the developed program. © ASCE.

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