Effect of slenderness ratio on compressive strength value of alkali-activated aluminosilicate composite with ceramic and fly ash precursor

Abstract

The standard test method for the compressive strength of the cylindrical specimens represents one of the ways to characterize building materials. The test results depend on the ratio of the specimen’s length to cylinder diameter (slenderness ratio). This relation is well known and researched for typical building materials (concrete, mortars) and some rocks. The respective standards recommend ways to solve this problem (e.g., using the slenderness correction factors). The situation is different for newly developed and non-traditional materials. Therefore, this paper deals with the effect of the slenderness ratio on the compressive strength value of selected fine-grained alkali-activated aluminosilicate composites: i) with a ceramic precursor, and ii) with fly ash. In total, 25 specimens with a diameter of 50 mm were tested for each investigated material. For the standard test method for compressive strength determination, six sets of specimens were prepared. Each set of specimens differed in the slenderness ratio, which was set to 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0. Based on the obtained compressive strength vs. the slenderness ratio relationship, the selected specimens were analyzed and characterized with the use of 3D high-resolution X-ray computed tomography.