Sulfate Attack of Limestone Powder–Cement Based Materials Under Low Temperature of the Sichuan-Tibet Railway

To research the performance of low-temperature sulfate corrosion resistance of concrete mixed with limestone powder of the Sichuan—Tibet railway, the effect of limestone powder-cement on the sulfate attack behavior of cement-based materials under low temperature was studied and the non-monotone Wiener stochastic process model was established to predict the service life of limestone powder-cement based materials under sulfate attack in a low-temperature environment by testing the change of appearance erosion grade, quality evaluation parameters, compressive strength evaluation parameters, pore characteristics, and erosion products of cement-based materials mixed with different limestone powder content under the sulfate solution immersion erosion and electric pulse sulfate erosion of low temperature. The results showed that the reaction was slow under the sulfate immersion in a low-temperature environment during the erosion period, the appearance of limestone powder-cement based materials did not appear visible spalling and its mass continued to increase. The strength first increased and then decreased, the turning point appeared at 120 days of the erosion. The pores were first refined and then deteriorated and the turning point appeared at 90 days of the erosion. A small amount of thaumasite was formed at 180 days of the erosion. The electrical pulse accelerates the sulfate attack of limestone powder-cement based materials in a low-temperature environment. The surface of the samples began to flake, the quality and strength of the samples decreased, and the internal pores deteriorated at 60 days under electric pulse and sulfate erosion in a low-temperature environment. The more the content of limestone powder was, the more serious the thaumasite erosion damage was. The samples with the limestone powder content of 40% generated thaumasite at 60 days of the erosion, while the samples with the limestone powder content of 10% and 20% generated thaumasite at 90 days of the erosion. The reliability life degradation analysis based on Wiener stochastic process showed that the indoor accelerated erosion life of cement-based materials, with 10%, 20%, and 40% limestone powder under electric pulse and sulfate attack in a low-temperature environment, was 265 days, 130 days, and 105 days, respectively. © 2022 Editorial Department of Journal of Sichuan University. All rights reserved.