Reactive powder concrete for façade elements – A sustainable approach

Abstract

Reactive powder concrete (RPC) is a fairly novel material with extraordinary strength and durability properties. Due to these properties, it is increasingly being utilized for external façade cladding thus enabling a considerable reduction in the thickness of concrete elements. Commercial RPC formulations on the market are usually expensive and less sustainable due to high cement clinker contents. In this study, improved RPC formulations with higher amounts of supplementary cementitious materials (SCMs) were developed. The formulations were combined with different types of reinforcements ranging from steel fibres to fibre textile grids primarily to enhance the ductility and tensile strength of the composite material. The results showed that even with clinker replacement levels of up to ca. 40% of the total binder amount, a satisfactory mechanical performance of the RPC mixes could still be achieved. A fairly steep strength gain rendered heat treatment unnecessary. The materials displayed good flow properties and a reasonably short initial setting time. The incorporation of carbon textile fibre grids proved to be highly effective in improving the post cracking behaviour of the RPC. The results validated a more sustainable approach for RPC applied to thin façade elements.

Verification of the Structural Performance of Textile Reinforced Reactive Powder Concrete Sandwich Facade Elements

“…As emphasized in Figure 2, this paper focuses on presenting the methods and results pertaining to the local failure (anchorage) and wind load experimental tests, along with the verification of the overall behavior and detailed model of the sandwich element. The material development has been presented elsewhere for RPC [11,20], FC [25], GFRP [22] and TRRPC [21]. The component testing and modelling related to connector local failure and shear tests can be found in [24], and that concerning the four-point bending tests in [22].…”

“…RPC is synonymous to UHPC such that it consists of six to eight different components and aggregate size of 2 mm or less. Table 1 presents the average strength values for RPC, while other details can be found in [11]. Table 1.…”

“…Table 1. Average strength properties (28 days) for RPC (standard deviation in parenthesis), source: [11]. The textile grid applied in the TRRPC consists of carbon fibers with an epoxy coating.…”

Structural performance of GFRP connectors in composite sandwich facade elements

“…6). In the numerical modelling the material properties are used as input and the model is verified by its ability to reproduce the findings in the component tests regarding deformations, crack formations, etc., thus the procedure gives feedback to the material development discussed elsewhere (Mueller et al, 2015). This investigation covers not only the facade elements, but also their anchorage system.…”

Composite Behaviour of Textile Reinforced Reactive Powder Concrete Sandwich Façade Elements

“…Progressively more UHPC/RPC has been used in façades, due to the fact that this type of high performance concrete demonstrates extraordinary high strength and durability (Miccoli et al 2015;Ghoneim et al 2010;Rebentrost et al 2008). The addition of textile reinforcement to such a high performance matrix, designated here as textile reinforced reactive powder concrete (TRRPC), has been found to improve the post-cracking behaviour of high-strength concrete (Colombo et al 2015;Mueller et al 2016;Hegger et al 2012). The SESBE (smart elements for sustainable building envelopes) project, funded by the European Commission, focused on developing smart façade elements which are lighter, thinner and more adaptive than existing solutions through the utilization of nanomaterials and nanotechnology.…”