The change of calcium hydroxide in cement paste by FTIR technique using different pozzolan materials

Abstract

  This research aims to study the change of calcium hydroxide in cement paste by FTIR technique when using different pozzolan materials. The pozzolanic materials used are fly ash from source A (FA), fly ash from source B (BL), silica fume (SF), and glass waste powder (GP). The ratio of cement to pozzolanic was 90:10, 80:20, and 70:30 by weight of the binder. The change of calcium hydroxide in cement paste was studied by FTIR technique at wavenumber 500 – 4000 cm-1. The compressive strength of cement mortar was investigated at 1, 7, 14, and 28 days. The results showed that the calcium hydroxide peak at 3640 cm-1 decreased with increasing curing time and increased with cement replacement with pozzolanic material. The peak at an intensity of 970 cm-1, the calcium silicate hydrate's location, was also found. As a result of compressive strength, it was found that when the curing age increased, the compressive strength increased. Cement mortar with Silica fume as pozzolanic material provided the highest compressive strength, and fly ash from source B (BL) gave the lowest compressive strength. On the other hand, the compressive strength decreased as the percentage of replacement of pozzolanic material increased.