Paper Title
A Study on the Effects of Metakaolin From Toraget Village in Indonesia, on Cement Concrete Properties

The usage of pozzolanic materials as additive has provided a unique characteristics for the improvement of cement based materials. In this paper, the effects of Metakaolin from Toraget Village, North Sulawesi in Indonesia, are investigated based on the compressive strength at 3, 7 and 28 days and water absorption of cement concrete at 7 and 28 days. At this experimental works, cement is replaced by 5%, 10%, 15% and 20% Metakaolin (by weight of cement). Results show an improvement on compressive strength and water absorption resistance of metakaolin-blended cement concretes. Concrete with 10% Metakaolin replacement had found to exhibit 50%, 45% and 25% higher compressive strength at 3, 7, and 28 days, respectively, in comparison to that of Portland cement concrete. On the other hand, based on the summarized sorptivity value, the minimum water sorptivity was 11 and 4 (x10-4 mm/s1/2) at 7 and 28 days, respectively, for concrete containing 10% Metakaolin.The findings are also consistence with volume of permeable voids results. This can be due to the chemical reaction and physical properties of Metakaolin in improving the microstructure and the formation of Calcium Silicate Hydrate (CSH) gel. Index Terms— Cement, Compressive Strength, Metakaolin, Volume of Permeable Voids, Water Absorption.