| Popis: |
This article describes how most standardization agencies allow small-cylinder specimens (100 x 200 mm [4 x 8 in.]) to be used in compressive strength concrete testing. However, some engineers are still skeptical about using small cylinders, as they believe that compressive strength testing results from small cylinders are too varied. Limited studies have been conducted regarding the precision of small cylinders compared to precision studies for conventional cylinders (150 x 300 mm [6 x 12 in.]). This paper describes the results of a comparative concrete testing program conducted by 15 laboratories in Edmonton, AB, Canada, over the past 10 years. This study attempted to develop within-laboratory (repeatability) and between-laboratory (reproducibility) precision indexes for small and conventional concrete specimens by analyzing more than 2700 compressive strength concrete testing data within a compressive strength range of 17 to 57 MPa (2500 to 8300 psi). |
