Protective or damage promoting effect of calcium carbonate layers on the surface of cement based materials in aqueous environments

Journal Article · Wed Sep 15 00:00:00 EDT 2010 · Cement and Concrete Research

DOI:https://doi.org/10.1016/j.cemconres.2010.05.001· OSTI ID:21418103

Schwotzer, M ^[1]; Scherer, T ^[2]; Gerdes, A ^[1]

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1. Karlsruhe Institute of Technology, Institute of Functional Interfaces, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany)
2. Karlsruhe Institute of Technology, Institute for Nanotechnology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany)

Cement based materials permanently exposed to aggressive aqueous environments are subject to chemical changes affecting their durability. However, this holds also for tap water that is considered to be not aggressive to cementitious materials, although in that case a formation of covering layers of CaCO{sub 3} on the alkaline surfaces is commonly supposed to provide protection against reactive transport processes. Thus, investigations of the structural and chemical properties of the material/water interface were carried out in laboratory experiments and case studies to elucidate the consequences of surface reactions for the durability of cement based materials exposed to tap water. Focused Ion Beam investigations revealed that a protective effect of a CaCO{sub 3} covering layer depends on its structural properties, which are in turn affected by the hydro-chemical conditions during crystallization. Surface precipitation of CaCO{sub 3} can trigger further chemical degradation, if the required calcium is supplied by the pore solution of the material.

• OSTI ID: 21418103
• Journal Information: Cement and Concrete Research, Vol. 40, Issue 9; Other Information: DOI: 10.1016/j.cemconres.2010.05.001; PII: S0008-8846(10)00120-1; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0008-8846
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CALCITE
CALCIUM CARBONATES
CEMENTS
CHEMICAL PROPERTIES
CRYSTALLIZATION
DAMAGE
DRINKING WATER
INTERFACES
ION BEAMS
LAYERS
PRECIPITATION
SURFACES
ALKALINE EARTH METAL COMPOUNDS
BEAMS
BUILDING MATERIALS
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATE MINERALS
CARBONATES
HYDROGEN COMPOUNDS
MATERIALS
MINERALS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
SEPARATION PROCESSES
WATER