Freeze-thaw cycling damage evolution of additive cement mortar

Abstract

To analyse the different mechanism of polycarboxylate superplasticizer and polyester fibre and its effect on cement mortar during freeze-thaw cycles, by taking cement mortar as main research object and the proportion of additive as variables, the varying pattern of the mechanical properties, size and distribution of the pores of the cement mortar during freeze-thaw cycles were studied by the NMR technology for the first time. The influence of different proportion of additive on the changes of the surface scaling, mass, compressive strength, splitting tensile strength and elastic modulus of cement mortar after 0, 25, 50, 75 and 100 times freeze-thaw cycles was studied. Meanwhile, the T₂ spectra change law of the cement mortar under different freeze-thaw environment was analysed and the change rule between freeze-thaw cycle, additive proportion and the pore size within the cement mortar was obtained. Also, the relationship between the mechanical parameters and pore properties was studied. This study on the damage evolution mechanism of additive cement mortar during freeze-thaw process is of great theoretical and practical significance to the analysis and prevention of freeze-thaw disasters in cold area.

Keywords:

• Freeze-thaw cycles
• NMR
• additive cement mortar
• mechanical property
• pores property

Disclosure statement

The authors declare that there is no conflict of interest regarding the publication of this paper.

Additional information

Funding

This paper gets its funding from Project (51474252, 51774323) supported by National Natural Science Foundation of China; The National Key Research and Development Program of China (2018YFC0808404); The Key Research & Development Program of Hunan Province (2017GK2190). Project (2018JJ3676) supported by Natural Science Foundation of Hunan Province, China. The authors wish to acknowledge these supports.