Optimisation of rheological parameters and mechanical properties of superplasticised cement grouts containing metakaolin and viscosity modifying admixture

► Percentage of SP, VMA, and MTK had a significant effect on the fluidity, rheology, and setting times. ► MTK significantly reduced setting times and improved the compressive strength at 3 d, 7 d, and 28 d. ► The desirability function increased with an increase in % MTK and tended to reduce when SP increased.