Experimental Study on the Performance of Improved Collapsible Loess Mixture with Concrete Crushed Gravel

Abstract

Based on the climatic and geological characteristics of the non-weight collapsible loess area, the paper analyses the cooperative working conditions of the concrete surface structure and the non-weight collapsible loess subgrade. The thesis uses coal gangue powder, fly ash, calcium carbide slag powder, and silica fume to modify the permeable concrete, and studies the unconfined compression test after the modification, the load ratio (cbr) test, and the eds-sem scanning electron microscope test. And other physical and mechanical properties. The experimental results prove that the modified soil with 30% calcium carbide slag powder after 28 days of curing has the best compressive performance, but has a heavier industrial peculiar smell; 30% silica fume and 30% silica fume are mixed the compressive performance of the modified soil with coal gangue powder is close; the compressive performance of the modified soil with 30% fly ash is relatively low. Among the four different admixtures in the test, the improved soil mixed with 30% calcium carbide slag powder and 30% concrete gravel has the best compressive effect, and the other three improved soils have similar effects. In the experiment, after four different admixtures were used to improve soil mixing and concrete crushed gravel, the bearing ratio of the modified soil obtained by mixing 30% calcium carbide slag powder and 30% concrete crushed gravel was the best and much higher than that of the other three materials. Scanning through the electron microscope, it was observed that the admixture had a greater effect on the adhesion of the soil foundation and the concrete gravel, which made the soil structure more stable.