Title: Ratios of Compressive Strengths of Ultra-High-Performance Concrete Specimens of Different Shapes and Sizes

Author(s): Philipp Riedel, Torsten Leutbecher, Siemon Piotrowski, and Christian Heese

Publication: Materials Journal

Volume: 116

Issue: 6

Appears on pages(s): 139-149

Keywords: compressive strength; conversion factor; cube; cylinder; guideline; strength class for concrete; strength test; ultra-high-performance concrete (UHPC)

DOI: 10.14359/51716983

Date: 11/1/2019

Abstract:
So far, there has been a lack of generally applicable factors to convert between compressive strengths obtained in tests on ultra-high-performance concrete (UHPC) specimens of different shapes and sizes. Thus, a test program covering compression tests on 150 and 100 mm (6 and 4 in.) cylinders and cubes was initiated. For comparison reasons, ordinary-performance concrete (OPC), high-performance concrete (HPC), and UHPC mixtures without fibers were examined. The maximum aggregate size of the UHPC mixtures was 0.5, 3, 5, and 8 mm (0.020, 0.12, 0.20, and 0.31 in.), which covers the scope of application. The mean cylinder compressive strengths ranged between 30 and 200 MPa (4.35 and 29.0 ksi). Very small coefficients of variation of test results document high accuracy and validity obtained by standardized procedures throughout fabrication and testing. Compared with OPC and HPC, the effect of specimen’s geometry on the compressive strength is very small for UHPC.