Shandong Science ›› 2022, Vol. 35 ›› Issue (1): 65-72.doi: 10.3976/j.issn.1002-4026.2022.01.009

• New Materials • Previous Articles     Next Articles

Porosity development analysis of concrete under sulfate attack based on nuclear magnetic resonance

WANG Cheng-ping1(),ZHANG Jia-sheng2   

  1. 1. Training Base for the Integration of Production and Education of Construction and Rail Transit,Xi'an Vocational and Technical College, Xi'an 710038, China
    2. Xi'an Municipal Construction Engineering Quality Inspection Co., Ltd., Xi'an 710038, China
  • Received:2021-02-23 Online:2022-02-20 Published:2022-01-25

Abstract:

To determine the degradation pattern of pore structures during concrete damage under different sulfate mass fraction, the freeze-thaw cycle test of concrete under different sulfate mass fraction is performed herein. Using nuclear magnetic resonance technology, the change in porosity during concrete damage is analyzed, in addition to the mass loss and relative dynamic elastic modulus change. The results show that the first peak of T2 spectrum changes significantly under different sulfate mass fraction. In the same period of the freeze-thaw cycle, the change range of the T2 spectrum first peak increases with increase in the sulfate mass fraction. An exponential relation exists between the first peak area of T2 spectrum and the number of freeze-thaw cycles in the salt-freezing environment, and a linear relation exists in the water-freezing environment. There is a linear relation between the development of microporosity and the number of freeze-thaw cycles. There is a significant linear relationship between the porosity and the number of freeze-thaw cycles and sulfate mass fraction. The mass loss and the relative dynamic elastic modulus loss in the salt-freezing environment increase with increase in the sulfate mass fraction.

Key words: concrete, sulfate attack, nuclear magnetic resonance, T2 spectrum, freeze-thaw cycle, porosity

CLC Number: 

  • TU528