Sessions & Events

 

All sessions and events take place in Central Daylight Time: CDT (UTC-5). On-demand sessions will be available for viewing in the convention platform under "On-Demand Content" within 24-48 hours of the session premiere. Please note, on-demand sessions are not available for CEU credit. * Denotes on-demand content.

H=Hyatt Regency Dallas; U=Union Station

Current Practices for Advanced Analysis Techniques of Concrete, Part 2 of 2

Tuesday, October 25, 2022  11:00 AM - 1:00 PM, H-Reunion C

This session provides general information on various analytical techniques used to characterize concrete material properties. The purpose of this session is to provide an overview of available methods and offer guidelines to both, the researchers and practitioners, as to how they can be utilized. For each technique presented, practical information such as best use, sample type, test procedures, results analysis, and limitations will be discussed.
Learning Objectives:
(1) Discuss hardened concrete characterization techniques;
(2) Investigate capabilities of advanced analysis techniques;
(3) Describe fundamental principles and limitations;
(4) Identify research and industry applications for advanced analysis techniques.

This session has been AIA/ICC approved for 2 CEU/PDH credits.


Advanced Characterization of Cementitious Systems using X-ray Diffraction Analysis

Presented By: Farshad Rajabipour
Affiliation: Pennsylvania State University
Description: Advanced Characterization of Cementitious Systems using X-ray Diffraction Analysis X-ray diffraction (XRD) can be used for characterizing the crystalline phases present and quantifying the amorphous content of fine-grained anhydrous and hydrated cementitious materials. Given the complexity of cementitious materials, sample preparation, measurement setup, and data analysis play a key role in obtaining reliable results from XRD analysis. Two case studies are presented to describe the use of this technique for the quantitative phase analysis of hydrated cementitious pastes and to describe the relative advantages and disadvantages of the different protocols available. In the first case study, the early age (= 24 hours) phase composition of blended cementitious pastes was obtained using in-situ XRD analysis with external standard method and minimal sample preparation. In the second case study, internal standard method with appropriate sample preparation steps (hydration stoppage and grinding) was used to obtain the later age (7, 28, and 56 days) phase composition of blended cementitious pastes.


Raman Spectroscopy & Imaging: What, How, and Why?

Presented By: Nishant Garg
Affiliation: University of Illinois at Urbana-Champaign
Description: Raman spectroscopy has been used in the characterization of cementitious materials for nearly 50 years. However, hyperspectral mapping or Raman imaging is a relatively new technique that produces phase maps or spectral images of sample surfaces by collecting a Raman spectrum on every pixel. Over the last 10 years, the capabilities of Raman imaging have significantly improved, primarily due to hardware and software advancements in the Raman confocal microscopes and spectrometers. In this talk, the audience will learn what is Raman spectroscopy and imaging and how this technique works on various concrete ingredients. Specifically, applications on heterogeneous ingredients of concrete (ranging from aggregate to cement clinkers) will be shared, where this technique enables accurate and precise phase quantification via a mapping approach at a high spatial, sub-micron resolution. Finally, with an outline of recent advancements and challenges, the audience will learn the potential future role of this tool in the domain of concrete characterization.


Principles of Fourier Transform Infrared Spectroscopy and Applications to Alkali Activated Binders

Presented By: Narayanan Neithalath
Affiliation: Arizona State University
Description: This talk provides the results of a study implementing IR spectroscopy and associated spectral deconvolution to track the reaction progress in slags activated using Na or K silicate solutions. A Fourier self-deconvolution process, implemented in a custom-developed code is used for spectral deconvolution. The variations in the Si-O-T (T=Si or Al) antisymmetric stretching vibration occurring in the range of 940 cm-1 to 960 cm-1 is used to infer the influence of reaction time, temperature, and activator characteristics. The spectral deconvolution process highlights the growth of the Si-O-T band at the expense of Si-O symmetric bands, indicating the decrease in the amount of non-polymerized silica (Q0) to form more polymerized silica species (Q1 to Q2).


Pore Solution Expression and Analysis- A Tool for Monitoring Early Age Hydration and Durability in Portland Cement and Alkali-Activated Systems

Presented By: Sulapha Peethamparan
Affiliation: Clarkson University
Description: The composition of the pore solution is an essential component in determining the early age hydration reaction processes in portland and alkali-activated binder systems. The pore solution chemistry helps to delineate the hydration kinetics and the mechanism of cement hydration. The ionic composition of the pore solution can also reflect the potential of alkali-silica reaction, corrosion resistance, and carbonation of concrete, therefore, contributing to the understanding of the long-term durability of concrete. In the first part of this presentation, pore solution extraction and analysis methods will be discussed in detail, and some practical guidelines and recommendations will be made. The second part of the presentation will discuss how pore solution chemistry can predict the early age reaction kinetics in the portland and alkali-activated system. Finally, the pore solution chemistry and long-term durability relationship will be discussed.


Application of Advanced X-ray and Neutron Imaging Techniques in Durability Design of Concrete Systems

Presented By: Mehdi Khanzadeh Moradllo
Affiliation: Temple University
Description: The durability of concrete in different environments is still a topic of continuing interest due to its scientific complexity and economic impact. This presentation discusses the important role of advanced X-ray and Neutron imaging techniques in a deeper understanding of the deterioration mechanisms in concrete materials at a microstructural level. Additionally, it highlights how the micro-scale study of concrete materials enables us to manipulate and tailor the microstructure of materials. This opens up tremendous opportunities in developing high-performance and novel concrete materials.


Case Studies of Concrete Petrography and Image Analysis on Durability Deterioration Mechanisms

Presented By: Chunyu Qiao
Affiliation: Wiss, Janney, Elstner Associates, Inc.
Description: Concrete durability is influenced by different mechanisms that involve interactions between external substances and internal materials. For instance, the absorbed water in concrete can cause freeze-thaw damage in cold weather regions, and the penetration of chloride-based deicers can deteriorate concrete and accelerate steel reinforcement corrosion. Concrete petrography, combined with image analysis and other tests, provides a powerful tool to diagnose durability related concrete deteriorations. This presentation will focus on case studies that use concrete petrography and image analysis to investigate several durability mechanisms.

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