碱碳酸盐反应的膨胀机理

EXPANSION MECHANISM OF ALKALI-CARBONATE REACTION

将具有碱碳酸盐反应活性的骨料置于已知浓度的碱溶液中,通过分析溶液中碱离子浓度的变化,分析和探讨碱碳酸盐反应的膨胀机理。实验证实:去白云石化反应的产物层中除了方解石和水镁石外,还有K+,Na+和CO32-,即去白云石化反应的反应产物K+,Na+和CO32-并不回到孔溶液中,而是保留在产物层中占据一定的空间。因此,去白云石化反应产物所占据的空间大于参加反应的白云石所占据的空间,从而引起膨胀。

The aggregates with alkali-carbonate reactivity were put into basic solution, and the concentration changes of alkali ions in solution were tested. Through analyzing the progress of alkali-carbonate reaction and the experiment results, a new mechanism of expansion due to alkali-carbonate reaction was put forward. It was found that there is not only calcite and brucite but also K+, Na+ and CO32- existing in the reaction product layer of alkali-carbonate reaction. Expansion occurs because K+, Na+ and CO32- occupy space and the space occupied by the reaction products of dedolomization is greater than that the dolomite taking part in the dedolomization.