e recycling of construction waste slurry is an urgent issue that needs to be solved in urban construction. To satisfy the requirements of subgrade filling, mechanical properties of fiber/cement-modified slurry were investigated. Unconfined compression tests were conducted for 7-day-cured specimens with a cement content of 5%, 10%, 15%, 20%, 25%, and 30%, respectively. Moreover, the effects of fiber contents (0.25%, 0.5%, 0.75%, and 1%, respectively) were also investigated for the specimens with a cement content of 20%. A formula satisfying the accuracy requirement was obtained by fitting the stress-strain curves using the back propagation (BP) neural network algorithm. Five parameters, including peak strength, failure strain, initial elastic modulus, residual strength, and energy dissipation, were used to characterize the short-term strength properties of fiber/cement-modified slurry. e analysis revealed that the cement content had a dominant effect on the short-term strength properties of fiber/cementmodified slurry, while the influence of fiber content was insignificant.

This study investigated the unconfined compressive strength change law of cement modified slurries (CMS) under different curing ages. We conducted unconfined compressive strength tests using slurry and cement as raw materials. The cement contents were 5%, 10%, 15%, 20%, and 25%. The curing ages were 7, 14, 28, 56, 90, 120, 150, and 180 d. A time effect model of CMS strength was established based on the measured UCS strength-curing age and the strength-cement content curves. The test results proved that the UCS of the CMS increased significantly with an increase in the curing age, and after 90 days, the UCS gradually increased to a fixed value. The time effect model better characterized the relationship between the UCS of the CMS and the curing age and the cement content, as the predicted value had a high correlation with the measured value. We conducted scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD) tests to analyze the microstructure and chemical composition of the CMS. The microscopic test results demonstrated that the increase of cement content and curing age increased the amount of gelling substances in the CMS and made the overall structure more compact, thereby increasing its macro strength.