Dataset on the reproducibility of UHPC mechanical properties under a fixed recipe with controlled production variability.

A dataset was collected to investigate the reproducibility of ultra-high performance concrete (UHPC) quality under controlled variability, since UHPC mechanical properties can vary even when using a fixed mix formulation in production. This dataset is the first open-access dataset in the UHPC community to take a holistic view of the UHPC production process and associated production variability, featuring a relatively large number of systematically designed experiments under a fixed recipe. A reference UHPC recipe, designed for a 28-day compressive strength of 120 MPa, was used to produce 150 experimental records, while the quality, storage conditions, and dosing accuracy of raw materials, along with mixing parameters and curing conditions, were systematically varied to emulate real-world production environments. For each batch, five fresh UHPC properties and the average mixer power were recorded, and compressive and flexural strengths at 24 hours and at 28 days were measured using standardized methods under controlled laboratory conditions. By linking process variability to mechanical outcomes under the fixed reference recipe, the dataset supports reproducibility analysis in UHPC production and provides reusable data for machine learning, uncertainty modeling, and digital-twin development.