Study on corrosion resistance of Portland cement-calcium sulphoaluminate cement binary system in a sodium chloride environment

Under marine condition, chloride migration is the main cause of the failure of concrete structures. In our previous study, Portland cement (PC) mixed with C4A3$ showed good performance in compressive strength, linear expansion and volume stability. In this work, Portland cement- calcium sulphoaluminate (CSA) cement binary system was detailed analysed, while 10%, 20% and 30% of Portland cement was replaced by calcium sulphoaluminate cement. Testing methods of isothermal calorimetry, X-ray diffractometry (XRD), X-ray fluorescence (XRF) were also performed. Results show that binary system of 80% PC and 20% CSA cement showed a good performance in compressive strength, the compressive strength can be up to 50 MPa and was higher than the other blended samples at 28 days in NaCl solution. Moreover, blended sample with 20% CSA cement shows good performance in chloride ions corrosion resistance.