Abstract: In order to study the durability of solidified soil in dry environment, bentonite and glass fiber were used to improve the cement solidified soil, and the crack evolution characteristics and strength deterioration of solidified soil in dry environment were studied. The influences of bentonite content and fiber content on crack index and unconfined compressive strength of solidified soil were analyzed, and the microstructure degradation mechanism of solidified soil was studied by scanning electron microscope. The results show that the addition of bentonite and fiber to solidified soil can significantly improve the durability of solidified soil in dry environment. When the bentonite content is 6% (mass fraction) and the fiber content is 0.3% (mass fraction), the improvement effect of solidified soil is the best. The unconfined compressive strength loss rate of specimen with curing age of 28 d after drying test is only 3.6%, and there is still a high residual strength after the peak stress, and there is no obvious crack on the surface of specimen. The evaporation of water in dry environment leads to the increase of porosity and pore volume of specimen, and the decomposition of hydration products, resulting in cracking and strength deterioration of specimen.

Key words: solidified soil, bentonite, glass fiber, dry environment, crack evolution, strength deterioration