Mechanical characterization and material variability effects of emerging non-proprietary UHPC mixes for accelerated bridge construction field joints

Accelerated bridge construction (ABC) field joints, e.g. precast deck panels joints, are among the common structural applications of ultra-high performance concrete (UHPC). The higher cost and limited availability of commercial UHPC products have motivated researchers to develop non-proprietary UHPC (NP-UHPC) using locally available materials. One of these efforts is the recent work by the ABC University Transportation Center (ABC-UTC) in the United States to develop NP-UHPC mixes for use in ABC field joints. This paper documents the ABC-UTC mix design and proportions and has two main objectives. First, provide a full material characterization of such mix to allow for future replication and use of this material for different bridge applications as well as modeling purposes. Second, investigate the effect of material sourcing and variability, such as fine aggregate types and particle gradation, on the main mechanical properties of the material. The material characterization tests included flowability, compression, flexure, and direct tensile tests of the NP-UHPC mixes. The results from these tests are then compared with various proposed equations from the literature to verify their validity for use with the considered NP-UHPC mixes.