Publication Date

11-16-2018

Department

Ames Laboratory; Chemistry

Campus Units

Chemistry, Ames Laboratory

OSTI ID+

1498684

Report Number

IS-J 9891

DOI

10.1016/j.cemconres.2018.11.010

Journal Title

Cement and Concrete Research

Volume Number

116

First Page

65

Last Page

69

Abstract

Concrete grinding from highway maintenance operations produces large amounts of a highly basic liquid residue, posing a significant challenge to proper disposal. To discard this residue with little risk to human health or the environment, it should be solidified and its pH should be neutralized. Herein we present the serendipitous discovery that both goals can be met by treatment with citric acid. Through the use of 13C and 29Si solid-state NMR we determined that such treatment removes the calcium from the concrete structure, thus allowing the solubilization of its one-dimensional silica chains. These silica chains then cross-link in solution forming a highly porous silica material that is able to absorb the water from the residue. This new waste treatment process, which may utilize other acids with low water content, promises to facilitate a significantly improved methodology for the disposal of concrete grinding residue in a safe and environmentally friendly manner.

DOE Contract Number(s)

AC02-07CH11358

Language

en

Department of Energy Subject Categories

36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 54 ENVIRONMENTAL SCIENCES

Publisher

Iowa State University Digital Repository, Ames IA (United States)

Available for download on Saturday, November 16, 2019

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