Study on frost resistance and vegetation performance of seashell waste pervious concrete in cold area

Abstract

In order to study the frost resistance of different seashell waste pervious concrete in the cold coastal area of northern China, the slow freezing method is used, with the mass loss rate, strength and effective porosity as the evaluation indexes, which combined with scanning electron microscopy (SEM), backscatter (BSE), energy dispersive spectrometer (EDS) and atomic absorption spectrophotometer for comprehensive analysis. The freeze–thaw durability of pervious concrete prepared from kitchen (cook to 100 °C at least once) oyster waste, factory (no cooking) oyster waste, kitchen scallop waste, and factory scallop waste were researched separately. The results show that the addition of silica fume can significantly improve the compressive strength of the seashell pervious concrete, but the improvement of the resistance to freeze–thaw is limited, Choose 5% of silica fume as the optimal amount. The freeze-thaw durability of pervious concrete made from scallop waste is better than pervious concrete made from oyster shells. however, oyster shells are powdery and fall off during the freezing and thawing process, and scallop shells do not have this property. Finally, through three-year in-situ plant test and comparison of soil water-soluble calcium ion concentration, the feasibility of the seashell pervious concrete in the cold area of northern China is proved. At the same time, it is found that the calcium ion concentration in the pervious concrete plant soil layer of oyster shell has an increasing trend after 3 years of testing, which has a more favorable effect on plant growth.