Influence of water to cement ratio on mechanical performance of concrete canvas reinforced with warp-knitted spacer fabric

Abstract

Concrete canvas (CC) has been studied and applied for more than a decade; it has yet to be substantially studied in the field of water dosage. The unreasonable choice of water to cement ratio (w/c) might affect the quality and performance of CC. Thus, in this study, the experimental tests on the setting time, mechanical properties, X-ray diffraction (XRD), optical microscopy (OM) and scanning electron microscopy (SEM) of CC were carried out. The flexural and bursting behaviors in the early curing stage were also illustrated. The selected w/c was based on the water saturation level of CC during spraying. The obtained results indicated that mechanical properties of CC improved with the increase of w/c, while too much water somewhat delayed the hydration process in the first 3 days of curing. On the other hand, the low w/c would lead to insufficient hydration products and large size of loose defective structure in the interlayer of CC. An appropriate overdosage of water is considered suitable for CC solidification by spraying.