Autonomous Repair in Cementitous Material by Combination of Superabsorbent Polymers and Polypropylene Fibres: A Step Towards Sustainable Infrastructure
Manual maintenance and repair of cracks in concrete structures are often unsustainable because of associated labor,capital and environmental damage.Introduction of microfibers and superabsorbent polymers is a material solution to restrict crack propagation and enhance self-healing efficiency.Therefore,the study focus on development of a more sustainable cementitous system(cement mortar)comprising of polypropylene(PP)fibers and superabsorbent polymers(SAP)which would facilitate autonomous healing and recover original mechanical and durability properties of mortar.To investigate crack sealing and recovery in mechanical and durability properties of mortar post healing,specimens were damaged by compressive and flexural loading.Mechanical strength,sorptivity and water penetration of healed mortars were compared to that of undamaged mortar at same age to estimate recovery of original properties while crack sealing was investigated by means of optical microscopy.Experimental results show mortar with combination of PP fibers and SAP showed full recovery of mechanical strength after healing while recovery in durability up to 90%was recorded.Microscopic images show that average crack-sealing ratio of 85%could be achieved under moist condition by combination of SAP and PP fibers while sealing under drier air curing condition is also significantly higher than reference samples with only fibers.Crack width up to 330μm has been found to be completely sealed by carbonate crystals.Furthermore,mortar with SAP and PP fibers retain about 70%of their original 28-day strength after three cycles of loading while reference mortar samples were found to retain only about 40-50%of their original strength.Effective crack sealing and high recovery of original properties in mortars with SAP and fibers suggest that this material combination would reduce the need for environmentally damaging and expensive repairs during the service life which will be an important step towards achieving economical and environmentally sustainable construction practice.
super absorbent polymers self-healing green construction technology
Souradeep GUPTA KUA Harn-wei PANG Sze-dai
National University of Singapore,Singapore
国际会议
2017世界可持续建筑环境大会(the World Sustainable Built Environment Conference)
香港
英文
2866-2873
2017-06-05（万方平台首次上网日期，不代表论文的发表时间）