Influence of 3D spacer fabric on drying shrinkage of concrete canvas

Concrete canvas has taken attention for their rapidly deployable hardened characteristic property in civil engineering. However, the drying shrinkage of concrete canvas has not been addressed yet in the literatures. In this study, a theoretical model was presented for studying influences of 3D spacer fabric on drying shrinkage of concrete canvas. The model was based on assumption that drying shrinkage restraint provided by 3D spacer fabric is joint action of each component of 3D spacer fabric separately. To calibrate this model, the drying shrinkage of two concrete canvases reinforced by PET-based 3D spacer fabric with one solid outer textile substrate was experimented. Moreover, a simplified expression of maximum tensile stress generated in the matrix of both concrete canvases was obtained for evaluating their risk of drying shrinkage-induced cracking. The results showed that drying shrinkage strain of concrete canvas samples became lower due to the restraint provided by 3D spacer fabric and a satisfactory correlation between model predictions and experimental results was found at later age. For both concrete canvases, a greater restraint was found in warp direction, thereby resulting in a larger tensile stress generated in the matrix. Furthermore, the restraint on the drying shrinkage of concrete canvas was provided mostly by spacer yarns and thereby it contributed to the most of maximum tensile stress generated in the matrix of concrete canvas.