Integrating Wire Arc Additive Manufacturing into Selective Paste Intrusion for Reinforced Concrete Elements: Effect of Temperature on the Mechanical Performance (Dataset)

This dataset accompanies the open-access conference paper of the same name, published in ce/papers 6 (2023), No. 6 (ibausil 2023, Ernst & Sohn / Wiley, DOI 10.1002/cepa.2817). The study investigates how external temperature exposure affects the flexural and compressive strength of hardened concrete produced by Selective Paste Intrusion (SPI) in combination with Wire Arc Additive Manufacturing (WAAM). WAAM locally introduces heat from the arc welding of the steel reinforcement, which can disturb hydration of the surrounding cement paste in the bonding zone around the reinforcing bar. To isolate this effect, prismatic specimens of 40 x 40 x 160 mm, produced in accordance with DIN EN 196-1 with a concrete composition similar to the SPI process, were heated in an oven preheated to 230 °C until defined target temperatures were reached. Temperature loads ranged from 30 °C to 100 °C in steps of 10 °C plus 150 °C and 200 °C, with reference specimens conditioned at 20 °C and 65 % relative humidity. Three specimens per temperature level were tested at a concrete age of 28 days, first in flexure on the prisms and then in compression on the two prism halves. The results indicate that concrete temperatures in the fresh state up to 70 °C did not weaken the mechanical performance, whereas the strengths declined at 80 °C and above. The dataset contains the raw and processed measurement data underlying the study. The Rohdaten folder holds the Almemo temperature log of the oven test, recorded on 2022-08-18 with an Ahlborn Almemo 2890-9 data logger and provided as CSV, TXT and XLS (same content, three formats), together with photographs and a video documenting the specimens, the formworks in the oven and the test setup. The Auswertung folder holds the strength evaluation spreadsheet Ergebnis_Temp_BZ_DF.xlsx with the flexural (Biegezug, BZ) and compressive (Druckfestigkeit, DF) results per temperature level that feed the figures of the paper. Technical notes: the spreadsheets are provided in Microsoft Excel format (.xlsx, .xls) and can be opened with Excel or LibreOffice Calc, or read programmatically, for example with Python (pandas). The temperature log is additionally available as plain CSV and TXT. The photographs are JPEG images and the video is in QuickTime (.MOV) format. No software beyond a spreadsheet application, a text editor and a standard image and video viewer is required. Methodology in brief: an ordinary Portland cement paste with a water-to-cement mass ratio of 0.35 and a superplasticizer, adjusted to a mini-slump flow between 400 and 410 mm, was combined with quartz sand aggregate of 1.0 to 2.2 mm particle size at a volumetric ratio of 42 % cement paste to 58 % aggregate. The paste amount was derived from the void content of the particle bed via bulk and mass density. A temperature sensor was placed in the centre of each formwork, and the oven temperature was monitored until the target temperature was reached. After heating, the prisms were stored for 24 hours in a climatic chamber at 20 °C and 65 % relative humidity under a damp burlap cloth, then demoulded and kept in the climatic chamber until testing per DIN EN 196-1. This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), project number 414265976, within the Transregio TRR 277 Additive Manufacturing in Construction (AMC).