Author(s)

C. Joh, H. Hwang & B. Kim

Abstract

Ultra High Performance Concrete (UHPC), compared to conventional concrete, shows highly improved structural behavior, which makes it possible to design slender, light and durable structures. However, further development of practical design formulas is required to apply UHPC to a structural design. This paper reports the result of two independent punching shear tests of UHPC slabs to estimate the punching strength of UHPC slabs. To recommend the reliable punching shear formula for the design of UHPC slabs, the test results are compared to available punching shear formulas for conventional concrete and UHPC. Also, a detailed comparison between the two tests is made to understand the important factors affecting the structural behavior of UHPC slabs. Based on the results, design considerations for UHPC slabs are recommended. Keywords: UHPC slab, casting procedure, flexural capacity, punching shear. 1 Introduction In general, the design of a slab requires the flexural and the punching shear strengths of the slab. Flexural and punching shear formulas for conventional concrete slabs have been developed based on numerous test results and analytical models. However, the flexural and the punching shear strengths of UHPC slabs are not yet fully developed for practical design, because it is a relatively new building material and the structural behavior of UHPC is different from concrete. This paper reports the result of two independent punching shear tests of UHPC slabs. First, three slabs made of UHPC developed by the Korea Institute of Construction Technology (KICT) are tested to estimate the punching strength of UHPC slabs (hereafter called the PT test). Then, two slabs, which have the same composition and dimensions as the previously tested UHPC slabs, are

Keywords

UHPC slab, casting procedure, flexural capacity, punching shear.