Influence of Initial Silica Modulus of Na₂SiO₃ on the Compressive Strength of Alkali Activated Ultrafine Palm Oil Fuel Ash Based Mortar

Abstract:

The influence of silica modulus (Ms) on the compressive strength of alkali activated ultrafine palm oil fuel ash based mortar has been investigated. Two alkali activated mortar mixtures, S₁ and S₂ were prepared using sodium silicate (Na₂SiO₃) with initial silica moduli, Ms of 3.3 and 2, respectively. The Na₂SiO₃ was used in combination with sodium hydroxide (NaOH) with NaOH concentration of 10 M. The results indicate that the S₂ mortar mixture has higher strength than the S1 mortar mixture at all testing ages, with 28 day strength of 27.18 MPa and 32.8 MPa recorded by S₁ and S₂ mortar mixture, respectively. Hence, lower Ms leads to higher compressive strength. The higher compressive strength of S₂ is corroborated by the formation of more C-S-H as implied by the Fourier Transform Infra-red (FTIR) spectra analysis.

• Periodical: Applied Mechanics and Materials (Volume 802)
• Pages: 202-207
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.802.202
• Online since: October 2015
• Authors: Otman M.M. Elbasir, Megat Azmi Megat Johari, Zainal Arifin Ahmad
• Keywords: Alkali Activated Mortar, Compressive Strength, FTIR, Initial Silica Modulus, Ultrafine Palm Oil Fuel Ash

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