EFFECTS OF ADMIXTURES ON HYDRATION HEAT OF CEMENT PASTE

Year 2007, Issue: 014, 73 - 86, 17.12.2007

A.Uğur Öztürk

Abstract

In this study, Trisodium citrate (C6H5Na3O7 – Ret. 1), citric acid (C6H8O7 – Ret.2) and tartaric acid (C4H6O6 – Ret.3)
were used to retard the hydration process of cement paste. Admixtures were investigated with respect to their effects
on the hydration heat of ordinary Portland cement. Heat liberation graphs of mixes during hydration process were
plotted by using isothermal calorimetry. Heat liberation of mixes varies due to their different rapid dissolution
properties. Cement paste without a retarder has an early setting time between all mixes. The calorimetric graphs
indicate that the setting time increases as the ratio of retarder increases. At the ratio of 0.2 %, tartaric acid has the
strongest effect on retardation.

Keywords

Hydration heat, Organic admixtures, Isothermal calorimetry

KATKILARIN ÇİMENTO HAMURU HİDRATASYON ISISINA ETKİLERİ

Abstract

Bu çalışmada, Trisodyum sitrat (C6H5Na3O7 – Ret. 1), sitrik asit (C6H8O7 – Ret.2) ve tartarik asit (C4H6O6 – Ret.3)
çimento harçlarının hidratasyon süreçlerini geciktirmek amacıyla kullanılmıştır. Katkılar Portland çimentosunun
hidratasyon ısısı üzerine etkileri ele alınarak incelenmiştir. Hidratasyon süreçleri boyunca karışımların ısı çıkışı
grafikleri izotermal kalorimetre kullanılarak çizilmiştir. Karışımların ısı çıkışları katkıların hızlı çözünme
özelliklerine bağlı olarak değişirler. Katkısız çimento hamuru bütün karışımlar arasında en erken priz süresine
sahiptir. Kalorimetre grafikleri katkı oranı arttıkça priz süresinin uzadığını işaret eder. 0.2 % oranında, tartarik asit
geciktirme üzerinden güçlü etkiye sahiptir.

Keywords

Hidratasyon ısısı, Organik katkılar, İzotermal kalorimetre

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