Experimental Study on the Effects of Mixing Waste Bricks and Recycled Concrete Crushed Stone on the Application of Road Base

Accelerated urbanization has led to increasingly prominent issues related to the accumulation and inefficient treatment of construction waste, particularly waste bricks, which are difficult to utilize on a large scale in road base courses due to their low strength and high water absorption. Therefore, this study investigated the combination of waste bricks and concrete crushed stone as a primary material for pavement base courses, and systematically explored the feasibility of its resource utilization. Through mechanical performance tests, three mix proportions with different waste brick contents (0%, 30%, and 50%) were designed, and compaction tests along with 90-day unconfined compressive strength tests were conducted. The results indicated that as the waste brick content increased, the crushing value of the mixture rose from 21.5% to 32.15%, the optimum moisture content increased from 14.07% to 19.51%, and the maximum dry density decreased from 1.874 g/cm³ to 1.678 g/cm³. The 90-day unconfined compressive strength decreased from 10.17 MPa (without waste bricks) to 6.12 MPa (with 50% waste bricks). The mixture with 30% waste brick content still met the strength requirements for base courses of secondary and lower-grade highways. In summary, waste bricks can be used in road base courses, but their content should not exceed 30%, and further modification is necessary to enhance their performance.