Why alite stops hydrating below 80% relative humidity

Journal Article · Thu Sep 15 00:00:00 EDT 2011 · Cement and Concrete Research

DOI:https://doi.org/10.1016/j.cemconres.2011.06.001· OSTI ID:21576916

Flatt, Robert J ^[1]; Bullard, Jeffrey W ^[2]

---

1. Sika Technology AG, Zuerich (Switzerland)
2. National Institute of Standards and Technology, Gaithersburg MD (United States)

It has been observed that the hydration of cement paste stops when the relative humidity drops below about 80%. A thermodynamic analysis shows that the capillary pressure exerted at that RH shifts the solubility of tricalcium silicate, so that it is in equilibrium with water. This is a reflection of the chemical shrinkage in this system: according to Le Chatelier's principle, since the volume of the products is less than that of the reactants, a negative (capillary) pressure opposes the reaction.

• OSTI ID: 21576916
• Journal Information: Cement and Concrete Research, Vol. 41, Issue 9; Other Information: DOI: 10.1016/j.cemconres.2011.06.001; PII: S0008-8846(11)00162-1; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0008-8846
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
CALCIUM SILICATES
CAPILLARIES
CEMENTS
EQUILIBRIUM
HUMIDITY
HYDRATION
REFLECTION
SHRINKAGE
SOLUBILITY
WATER
ALKALINE EARTH METAL COMPOUNDS
BLOOD VESSELS
BODY
BUILDING MATERIALS
CALCIUM COMPOUNDS
CARDIOVASCULAR SYSTEM
HYDROGEN COMPOUNDS
MATERIALS
MOISTURE
ORGANS
OXYGEN COMPOUNDS
SILICATES
SILICON COMPOUNDS
SOLVATION