The dataset contains research data supporting the paper: Brault, A and Lees, JM (2020) Wet casting of multiple mix horizontally layered concrete elements, Construction and Building Materials, v 247, 118514. This includes the data associated with the constituents of the concretes used in the layered specimens, fresh and hardened state properties of the concretes, and vibration times. These can be found in: • Table 1 - Concrete mix designations, constituent proportions, densities, and slump measurements. • Table 2 - Concrete mix constituent densities. • Table 3 - Vibration times. • Figure 2 - Concrete mix slump measurements versus density. In addition, data regarding the measured profile of the hardened layer geometry and the analysis of parameters that influence the distortion of the layer interface can be found in: • Table 4 - All specimen results, including CAD schematics of every cut. • Figure 8 - Comparison between maximum interface depth (Intmax) and various specimen properties: a) Intmax vs. yield stress of bottom layer mix, b) Intmax vs. the ratio of the top mix density over the bottom mix yield stress, c) Intmax vs. the yield stress difference between the top and bottom mix (top subtracted from bottom), and d) Intmax vs. the density difference between top and bottom mix (top subtracted from bottom). • Figure 9 - Yield stress of top mix vs yield stress of bottom mix with zones of different hardened interface types demarcated. • Figure 10 - Interface depth (Intmax) vs the average yield stress of both mixes for any specimen with similar workability on top and bottom (yield within 400 Pa of each other). • Figure 11 - Deposition influenced interface characteristics: c) vibration time vs. yield stress