Trade Journals for the Concrete Industry

In an earlier article (CPI issue of August 2011 [1]) a method was presented for producing precast curved panels with a thickness of a few centimeters using the 'flexible mould method'. This method is the central theme in the PhD study of the first author on the realization of free-form architecture in concrete (see fig. 1). The concrete panels manufactured with the flexible mould method can be applied for many architectural purposes in which curvature is present, such as façade cladding, precast plank floors or roof elements. The method essentially comprises a reusable and bendable smooth surface that can be deformed into a wide range of geometries, including variable curvatures in one or two directions and freely shaped edge contours. In the earlier article in CPI it was concluded that some aspects needed further research, among which were the choice of suitable concrete mixtures and the investigation of fibre reinforcement. This article discusses the results of experiments investigating these aspects: the mixture choice was guided by measuring the workability in time and the ability to undergo deformations after casting without cracking. Furthermore, AR-glass textile was used to strengthen the panels with a flexible reinforcement that allowed deformation in the non-hardened state. Experimental work has been done to check the position of the reinforcement after deformation and the contribution of the textiles to the strength of the panels.