Flexural behaviour of RC beams of modified concrete prepared by using metakaolin and M-sand

Concrete is a popular building material. Its compressive strength is higher than that of other building materials. The addition of pozzolanic elements as admixtures to concrete can improve its properties even more. Admixtures are generally natural or man-made substances that are added to concrete before or during mixing. To reduce the amount of clinker in concrete, metakaolin is used as an addition in the current experimental study. The building industry is expanding rapidly, as is the demand for sand. Overuse of river sand for construction has numerous negative environmental and social implications. The quality of river sand is deteriorating, and illegal sand mining is becoming an unmanageable problem. An excellent alternative to river sand is manufactured sand (M-Sand, MS). The current study reports experiments that were done to investigate the behaviour of RC beams under flexure when metakaolin (MK) is used in place of some of the cement and M-sand is used fully instead of river sand. In the current experimental study, MK was substituted for cement in the following percentages: 0, 2, 4, 6, 8, and 10% by weight of cement. For both standard and modified concrete beams, mechanical parameters are studied. RC beams of size 150×200×1500 mm were designed and casting and testing of these beams was done and four-point bending was considered. The failure load and maximum beam deflection were noted. The results indicate that MS can replace river sand fully and MK can be used in construction at lesser percentages.