Development of mix proportions for different grades of metakaolin based self-compacting concrete

Abstract

successfully used as an admixture in the preparation of self-compacting concrete (SCC). In order to prepare suitable mix proportions for different grades of metakaolin based self-compacting concrete, investigations were undertaken replacing cement with 0, 10, 15, 20, 25 and 30 % of metakaolin and with different percentages of superplasticizer (Glenium B233). As per the European guidelines for self-compacting concrete, slump flow test, V-funnel test and L-box test have been carried out on fresh properties of metakaolin based self-compacting concrete. The compressive strength, split tensile strength and flexural strength of the specimens have been analyzed for 7 and 28-days curing. In addition, finally mix proportions have been recommended for low, medium and high strength grades of metakaolin based self-compacting concrete. The fresh concrete test results revealed that by substituting different percentages of metakaolin in self-compacting concrete, satisfactory workability and rheological properties could be achieved, even though no viscosity-modifying agent was needed. In general, it seems that metakaolin can be considered as suitable replacement regarding to the economic efficiency, fresh and hardened properties of metakaolin based self-compacting concrete. The test results for acceptance characteristics of self-compacting concrete such as slump flow test, M V-funnel test and L-Box test were satisfactory as per EFNARC for developed mix proportions of M60, M40 and M20 grade self-compacting concrete mixes. Further, compressive strength, te sile strength and flexural strength at the ages of 7 and 28 days were also determined and 10-15 % replacement of metakaolin can be regarded as a suitable replacement and mix proportions have been recommended for low (M20), medium (M40) and high (M60) strength grades of metakaolin based self-compacting concrete from this study.