Research in Influence of External Factors on Properties of Portland-Cement under Conditions of Long-Term Storage

The reduction in the activity of Portland-cement under the impact of pre-hydration caused by environmental factors is considered. With the use of experimental methods the influence of adsorption moisture on the kinetics of heat emission and phase composition of Portland-cement stored in hermetic and non-hermetic containers has been studied. It is established that under normal conditions (21±1°C and 55±5% of humidity) the effect of pre-hydration causes a decrease in the concentration of active components of cement and an increase in the concentration of amorphous phase, Portlandite and calcium carbonates (aragonite and calcite). It is revealed that phases C3S and hemihydrates gypsum are most affected by the adsorption moisture. The peculiarities of changes in the heat flow and total heat emission at early stages of the hydration of the samples stored under different conditions during the year were studied using the method of isothermal calorimetry. It is established that only a slight decrease of activity is observed for the samples stored under hermetic conditions, but at the same time the activity of analogous samples stored under non-hermetic conditions reduces proportionally to the time of storage.

A.O. ADAMTSEVICH, Candidate of Sciences (Engineering)
A.V. EREMIN, Engineer, (This email address is being protected from spambots. You need JavaScript enabled to view it.)
A.P. PUSTOVGAR, Candidate of Sciences (Engineering)
S.A. PASHKEVICH, Candidate of Sciences (Engineering)

Moscow State University of Civil Engineering (26, Yaroslavskoe Highway, 129337, Moscow, Russian Federation)

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