Effect of Chemical Corrosion on Properties of SBS Modified Bitumen for Waterproofing Membranes

Abstract

SBS modified bitumen membrane used in underground engineering and coastal buildings would be corroded by chemical media, which greatly influenced the service life of waterproofing membranes. In this paper, SBS modified bitumen (MB), SBS modified bitumen with stone powder (MBS) and SBS modified bitumen with talc powder (MBT) were corroded by acidic, alkaline, and saline solutions for different time to evaluated the effect of chemical corrosion on the properties of SBS modified bitumen waterproofing membrane. The mass change ratio, low temperature flexibility, softening point and viscosity of SBS modified bitumen were investigated, and Fourier infrared spectroscopy (FTIR) was used to analyze the chemical structural changes of SBS modified bitumen after corrosion. The results showed that the mass of SBS modified bitumen decreased, the low temperature performance decreased, and the softening point increased after corrosion by chemical solutions. The influence of acidic and saline solution was more serious on SBS modified bitumen with fillers, and the properties of MBS has greatest degradation in acidic solution compared with MB and MBT. In alkaline solution, the properties degradation of MBT and MBS was less than that of MB, which indicated that filler could inhibit the alkaline corrosion of SBS modified bitumen. FTIR showed that C=C decreased more in acidic solution, while C=O and S=O of SBS modified bitumen increased significantly after alkaline solution corrosion, which indicated that acidic solution corrosion easily caused SBS degradation, while alkaline solution corrosion was easy to oxidize SBS and bitumen.