Study on the Sulfate Erosion Behavior of Cement-based Materials with Different Water-to-binder Ratios Containing Stone Powder in a Low-Temperature Saline Soil Area

Abstract

To research the performance of low-temperature sulfate corrosion resistance of concrete mixed with stone-powder in saline soil area of Qinghai-Tibet Plateau. In this work, the influence of the water-to-binder ratio and stone powder types on the low-temperature sulfate erosion behavior of cement-based materials was studied, and in order to predict its erosion life, a Wiener stochastic process model was established. The results show the following: 1) The samples of limestone powder cement-based materials (LCBM) with different water-to-binder ratios showed the same law in sulfate erosion; the greater the water-to-binder ratio is, the more serious the sample is eroded, and the difference is the rate of erosion reaction. The greater the water-to-binder ratio is, the earlier the characteristic peak of thaumasite appears. The electric pulse accelerated erosion lifetimes of the cement-based limestone powder with water binder ratios of 0.3, 0.4 and 0.5 were 185 days, 136 days and 110 days, respectively. 2) Quartz stone powder cement-based materials (QCBM) showed different erosion laws compared with LCBM. When soaked in sulfate, the macroscopic and microscopic changes of QCBM were basically in a mineral additives state, However, when the electric pulse accelerated the erosion, the QCBM was more severely attacked than the LCBM. The final erosion products of the cement-based limestone powder with water binder ratios of 0.4 are not only gypsum and ettringite but also thaumasite, while the quartz powder cement-based materials with water-binder ratios of 0.4 are only gypsum and ettringite.