Robotic Fibre Winding Reinforcement

Fundamental Structural Engineering Principles

Abstract

The Digital Fabrication with Concrete (DFC) enables freedom of form. In order to fully leverage this freedom, the reinforcement should be rethought, as well. Such an opportunity is provided by the Robotic Fibre Winding (RFW). This in-situ and on-demand produced fibre reinforced polymer reinforcement can provide endless strands, which can be either digitally deposited on concrete (concrete defines the form) or on a frame with subsequent application of concrete (reinforcement defines the form), and combined particularly successful with the digital shotcrete or Shotcrete 3D Printing (SC3DP).

The current paper critically analyses the results of the three previously published experimental campaigns with glass fibre wound reinforcement: 1) one set of pull-out and direct tensile tests with various RFW reinforcement types embedded in cast concrete, and 2) two sets of four-point bending tests with two different RFW reinforcement types. In all cases the experimental results are re-analysed from the structural engineering point of view, with the special consideration of anchorage length required for the full activation of reinforcement.

On basis of the obtained results it is concluded, that despite theoretically good bond, resulting in required anchorage comparable to this of classical steel bars, many bending tests unexpectedly ended in pull-out failure. Hence, the mode of pull-out failure should be carefully observed in the upcoming experiments. Likewise, the focus should be put in the future on collection of all relevant data required for such detailed investigation of the bonding zone.