Abstract
•A low-cement content and self-compacted UHPC dosage was developed.•Mineral admixtures such as calcium carbonate and recycled glass were incorporated.•Multi-criterion optimization was employed to ensure the threshold goals.•Statistical tools such as Pareto plots, ANOVA, and the design of experiments were used to understand the effect of the factors on the considered responses.•The methodology used can be extrapolated to optimize other concrete typologies.
This paper provides a multi-objective optimization approach to designing and manufacturing ultra-high-performance concrete (UHPC) with low cement content. Micro calcium carbonate and ground waste glass were employed as partial substitutes for cement and microsilica (MS) to achieve this goal. A three-factor design of experiments was used to achieve the most desirable rheological and mechanical properties with minimal quantities of cement and MS. In this context, the cement dosage (factor A), water-to-binder ratio (factor B), and superplasticizer dosage (factor C) were taken into account. By utilizing Andreasen & Andersen's (MAA) particle packing theory, dense particle packing was achieved throughout the experimental design. Regression models were developed to simulate the time-dependent rheological and mechanical properties of the UHPC. It was observed that the mathematical optimization was valid experimentally with reduced absolute deviations between 0.22 % and 1.23 % for slump flow and 3.49 % to 4.62 % for compressive strength at 28 days. The study showed that approximately 590 kg/m3 of cement would be most effective for recycled glass UHPC mixes. The proposed design will likely produce a compressive strength exceeding 150 MPa with satisfactory rheological properties at a lower cost.