Improving Testing to Rapidly Identify High-Quality Pozzolanic.pdf

Lisa Burris, The Ohio State University
Prannoy Suraneni, University of Miami
Thomas Robl, University of Kentucky Center for Applied Energy Research

Description

Improving Testing to Rapidly Identify High Quality Pozzolanic Supplementary Cementitious Materials Authors Dr. Lisa Burris - United States - The Ohio State University Dr. Prannoy Suraneni - United States - University of Miami Dr. Thomas Robl - United States - University of Kentucky Center for Applied Energy Research Abstract Coal ash has a long history of successful use in concrete mixtures as a pozzolanic material. Pozzolanic materials are aluminosiliceous or siliceous materials that participate in additional reactions with cement hydration products that densify the cementitious matrix and bind alkalis, increasing strength and durability of the concrete. However, with the reduction in coal-powered electricity the supply of fresh coal ash for use in concrete has also been reduced, resulting in shortages in many markets across the U.S.. As a result, new materials claiming to be pozzolanic in nature are being produced and marketed to concrete producers. Existing test methods, such as the Strength Activity Index (SAI) have significant shortcomings and may struggle to differentiate pozzolanic materials from inert fillers. Therefore, development of a pozzolanic reactivity test that can rapidly and accurately identify quality pozzolanic materials is needed. This talk will review currently commonly used reactivity test methods, the state of the art regarding pozzolanic reactivity testing, and compare and contrast these methods and principles with a newly developed method utilizing electrical resistivity. Early results from multiple research groups show that bulk resistivity not only easily differentiates inert and pozzolanic materials, but can do so rapidly, at much earlier ages than many other proposed methods.

 
May 15th, 11:30 AM May 15th, 12:00 PM

Improving Testing to Rapidly Identify High-Quality Pozzolanic.pdf

Grand Rapids, Michigan

Improving Testing to Rapidly Identify High Quality Pozzolanic Supplementary Cementitious Materials Authors Dr. Lisa Burris - United States - The Ohio State University Dr. Prannoy Suraneni - United States - University of Miami Dr. Thomas Robl - United States - University of Kentucky Center for Applied Energy Research Abstract Coal ash has a long history of successful use in concrete mixtures as a pozzolanic material. Pozzolanic materials are aluminosiliceous or siliceous materials that participate in additional reactions with cement hydration products that densify the cementitious matrix and bind alkalis, increasing strength and durability of the concrete. However, with the reduction in coal-powered electricity the supply of fresh coal ash for use in concrete has also been reduced, resulting in shortages in many markets across the U.S.. As a result, new materials claiming to be pozzolanic in nature are being produced and marketed to concrete producers. Existing test methods, such as the Strength Activity Index (SAI) have significant shortcomings and may struggle to differentiate pozzolanic materials from inert fillers. Therefore, development of a pozzolanic reactivity test that can rapidly and accurately identify quality pozzolanic materials is needed. This talk will review currently commonly used reactivity test methods, the state of the art regarding pozzolanic reactivity testing, and compare and contrast these methods and principles with a newly developed method utilizing electrical resistivity. Early results from multiple research groups show that bulk resistivity not only easily differentiates inert and pozzolanic materials, but can do so rapidly, at much earlier ages than many other proposed methods.