Effect of Aggregate Size and Specimen Dimensions on Mechanical Performance of Concrete

Abstract: Concrete is a heterogeneous material. Past research has established the effect of its primary constituents namely water, cement, aggregates on the behavior at the micro level as well as the macro level. In particular, several researchers have investigated the role of aggregates on the behavior of the concrete mix, the goal being to design aggregate gradations which results in higher concrete quality. The goal of this is to study the effect of specimen size on strength in unconfined concrete.
An experimental program to determine the compressive strength of a set of unconfined concrete cylinders of varying size (100mm, 150mm, 190mm diameter) and slenderness ratio of 2 is adopted. However, while studying the effect of meso-structure on strength and size effect, care has to be taken to ensure similar levels of workability and compaction in all specimens, since otherwise no meaningful conclusions can be drawn from the test results.
Average strength of specimen is taken and It is concluded from the experimental study that with increase in size of specimen its compressive strength is observed decreased.

Keywords: compressive strength Test, size effect, meso geometry