Mechanical properties of concrete cast in fabric formworks

Fabric formworks are permeable sheets made of synthetic textiles. The forms take the designed shapes (bags, bolsters, mattresses, or shuttering) under the pressure of pumped concrete mixes or cement mortars. The monolith of the structures built of these elements depends on the adhesion of the cement mortar or paste that drains throughout the fabric. The paper is aimed to provide civil engineers with guidelines for selecting a suitable textile and concrete mix. To achieve this, a series of tests was carried out. First, mechanical characteristics of various fabrics and their permeability were investigated. Next, concrete cubes were prepared from 12 concrete mixes molded in four types of fabrics. The cubes were subjected to destructive tests. On the basis of the laboratory results, the concrete compressive strength as a function of formwork and concrete mechanical parameters was obtained. The correctness of this relationship was estimated by use of the statistical analysis. (C) 2001 Elsevier Science Ltd. All rights reserved.