Effect of Graphene Oxide on Interfacial Transition Zone of Recycled Concrete(PDF)
《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]
- Issue:
- 2018年05期
- Page:
- 217-224
- Research Field:
- Publishing date:
Info
- Title:
- Effect of Graphene Oxide on Interfacial Transition Zone of Recycled Concrete
- Author(s):
- GUO Kai; MA Hao-hui; WANG Qiang
- School of Civil Engineering, Shenyang Jianzhu University
- Keywords:
- graphene oxide; recycled concrete; interface transition zone; microstructure
- PACS:
- -
- DOI:
- -
- Abstract:
- The micro-mechanical properties and microstructure characteristics of the interfacial transition zone of graphene oxide recycled concrete were studied by means of nanoindenter and scanning electron microscope. The results show that the elastic modulus of new motar and aggregate （XJ-G） interfacial transition zone increases by 18.54%, and the average volume of high density calcium silicate hydrate (HD C-S-H) phase increases by 17.8%, and the pore volume decreases by 9.1% using nanoindentation theory. The addition of graphene oxide makes the elastic modulus of the transition zone of recycled concrete new and old mortar (XJ-JJ) increases by 16.25% on average, the volume of HD C-S-H phase increases by 16.25% on average, and the pore volume decreases by 6.4% on average. The microstructure of the graphenerecycled concrete is observed by scanning electron microscopy. The crystals are in the form of flakes, and the crystal arrangement becomes more disordered. The orientation of calcium hydroxide (CH) crystal is weakened and the microstructure is more compact. The interface is defined according to the change of elastic modulus. The width of the transition zone is found to reduce the width of the transition zone of XJ-G interface by 25% and the width of the transition zone of XJ-JJ interface by 37.5%. Graphene oxide makes the elastic modulus distribution in the interfacial transition zone more stable, and the mean value of the elastic modulus tends to be uniform. From the relationship between the micromechanical properties and macroscopic mechanical properties of recycled concrete, it can be obtained that graphene oxide can enhance and improve the mechanical properties and microstructure of the transition zone between new and old interfaces of recycled concrete, and can improve the macroscopic mechanical properties of recycled concrete.
Last Update: 2018-09-03