Properties of strain-hardening cement composites with superabsorbent polymer particles

摘要

Strain-hardening cement composites (SHCCs), characterised by strain-hardening and multiple cracking behaviours under direct tension, are generally recognised as ductile and durable construction materials. The effect of the addition of superabsorbent polymer (SAP) particles and curing condition on the mechanical performance and microstructure of binary cement-based SHCC material using ordinary cement and fly ash as the cementitious binder was investigated in this study. Three different SHCCs were designed and mixed; the SHCC mixtures were reinforced with 2% polyvinyl alcohol (PVA) fibres by volume and 1% SAP was added to one SHCC mixture. The mixtures were subjected to compressive, flexural and direct tensile tests. The sealing and healing of cracks after direct tensile tests were also monitored by a microscope. The experimental results showed that the use of fine SAP particles led to an improvement in the mechanical properties of the binary cement-based SHCC material even under air curing. The multiple cracking, ductility and crack sealing were also improved by introducing 1% SAP particles. It is thus concluded that the addition of SAP may be an effective method to improve the sustainability of binary cement-based SHCC materials.