Experimental study on freeze-thaw resistance of modified magnesium oxychloride cement foam concrete

Magnesium oxychloride cement foam concrete specimenswere prepared by applying the inorganic-organic composite modification method to improve the water resistance of magnesium oxychloride cement and using the composite protein foaming agent for the purpose of foaming. Then, freeze-thaw cycle test was performed to examinethe frost resistance property of the specimens under the designed mix proportion. The experimental results show that: after 20 freeze-thaw cycles, neither macro-cracks nor hollow spalling are observed on the surface of the specimen, the strength loss rate is only 12%, and the compressive strength remains at a relatively high level of 1.46 MPa. Meanwhile, the microstructure of the specimen before and after the freeze-thaw experiment was analyzed through SEM test, and the failure mechanism during the freeze-thaw process was explained.