Enhancing concrete testing : Impact of modified specimen geometry on compressive and tensile strength

Frequently used in mechanical testing of concrete, cubic and cylindrical shapes are the subject of a number of studies questioning their influence on the material's strength. The aim of this study was to introduce a modified geometry to reduce the volume of test specimens and guarantee improved performance in strength tests, by investigating the effect of shape. Experimental results showed that the compressive strength of the modified shape was superior to that of standard shapes. However, due to its configuration, tensile strength was slightly improved. A regression analysis was carried out based on Bazant's formula for the effect of size. The results obtained indicate that this formula can be used to explain the proposed shape effect. In this respect, an empirical formula was proposed relating the compressive strength of the proposed specimens to the strength of standard specimens. A verification of the specimen damage model was also carried out in accordance with standards. Finally, a comparative analysis of the proposed geometry with existing literature was carried out.