Strength degradation of foamed cement paste under sulfate attack

Abstract

Foamed cement paste is increasingly being applied in the construction of road embankments, bridge abutments, slope treatments, and pipeline backfilling. Constructed foamed cement paste may suffer from sulfate attacks in certain environments, such as offshore regions and salty soil areas. However, the long-term performance of foamed cement paste under such circumstances remains unclear. In this study, laboratory tests are conducted to evaluate the strength deterioration of foamed cement paste after erosion by sulfate attack. Factors influencing the density of the foamed cement paste, concentration of the sulfate solution, and cation type (i.e., Na+ and Mg2+) are considered. The results indicate that the strength of the foamed cement paste decreases with increasing immersion time. The Na2SO4 solution has a more severe erosion effect than the MgSO4 solution when other conditions remain constant. Finally, X-ray diffraction is conducted to identify the phase of the crystalline material in the specimen. This study will be beneficial in the application of foamed cement paste in regions with salt-rich soils.