Preparation of concentrating agent using recycled concrete micropowder and its self-healing property

Abstract

An infiltration crystallisation concentrating agent was prepared using recycled concrete micropowder from construction waste as main material with instant sodium silicate, aluminium stearate and other active ingredients. The optimum mixture ratio and self-healing effect of the concentrating agent were studied. Compression experiments conducted in the laboratory were terminated when penetrating cracks appeared on the specimen. The specimen was then subjected to standard curing for 28 days after which, second pressure of the specimen was tested. Pore structures of the specimen pre-and post-curing were also tested. The self-healing property of the concentrating agent was characterised using the above comparative analysis. The results indicated that the concentrating agent possessed good self-healing capabilities. The optimum mixture ratio of the self-regenerating infiltration crystallisation concentrating agent is cement, 55%; quartz sand, 25%; instant 5% sodium silicate, 5%; aluminium stearate, 1%; recycled concrete micropowder, 20%; CaO, 8%; water–cement ratio, 0.6 and grey sand ratio, 1/3.

Keywords:

• Recycled concrete micropowder
• Infiltration crystallisation
• Concentrating agent
• Mercury intrusion technology
• Healing property