Mechanical Properties and Chloride Salt Corrosion Resistance of All-Lightweight Shale Ceramsite Concrete

In investigating the mechanical properties and chloride corrosion resistance of all-light shale ceramsite concrete (ALSCC), samples of ALSCC20-ALSCC45 with a compressive strength of C20-C45 were individually prepared. The compressive strength, split tensile strength, and elastic modulus of ALSCC were analyzed. Additionally, the chloride salt corrosion resistance of ALSCC was assessed by examining chloride ion penetration depth, steel corrosion rate, and compressive strength after ALSCC30 corrosion. Furthermore, the microstructure of ALSCC hydration products was observed using scanning electron microscopy (SEM). Results indicate that as the strength grade increases, the water-cement ratio decreases, and the internal structure becomes denser, thereby improving the mechanical and corrosion resistance properties of ALSCC. Notably, the chloride corrosion resistance of ALSCC surpasses that of ordinary concrete. SEM images reveal that the hydration of ceramsite with Ca(OH)2 in concrete generates Ca[Al(OH)4]2 precipitation and C-S-H gel, which enhances internal filling and improves chloride corrosion resistance. Furthermore, based on the results of the ALSCC30 corrosion test, a calculation model for predicting compressive strength in a chloride environment was proposed. This model effectively predicts the compressive strength of ALSCC under chloride exposure conditions.