为了实现固体废弃物资源化利用，提升青藏严寒地区再生混凝土砌块性能。在100 %再生粗骨料基础上，研究了再生细骨料和活性掺合料对大掺量固废再生混凝土承重砌块抗渗性、耐水性及抗冻性的影响，采用SEM、NMR分析了微观结构。结果表明：再生混凝土承重砌块渗透性和吸水率随再生细骨料的增加逐渐增大，随粉煤灰与矿渣复掺比的降低先减小后增大，抗冻性和软化系数变化规律则相反。当再生粗骨料取代率为100 %、粉煤灰与矿渣复掺比为3 : 1时，其抗压强度为11.77 MPa，抗折强度为3.89 MPa，软化系数为0.99，吸水率为0.7 %，冻融50次后质量损失率为2.2 %、抗压强度与抗折强度损失率分别为10.2 %和13.9 %，满足严寒地区承重及耐久性要求，可作为推荐配合比。微观显示碱激发促进了复合胶凝材料二次水化，生成更多的水化产物优化内部孔隙，混凝土结构密实。随着冻融次数的增加，砌块内部孔隙数量逐渐增多，微孔和中孔逐渐衍生为大孔和裂隙，砌块性能出现劣化。基于性能-成本-碳排放分析，单掺100 %再生粗骨料不利于低碳减排，混掺再生骨料和活性掺合料的推荐配合比碳减排率为31.03 %。

In order to realize the resource utilization of solid waste and improve the performance of recycled concrete blocks in severe cold regions of Qinghai-Tibet. On the basis of 100% recycled coarse aggregate, the effects of recycled fine aggregates and active admixtures on the impermeability, water resistance and frost resistance of high-volume solid waste recycled concrete load-bearing blocks were studied. The microstructure was analyzed by SEM and NMR. The results show that the permeability and water absorption of recycled concrete load-bearing blocks gradually increase with the increase of recycled fine aggregate, and decrease first and then increase with the decrease of fly ash and slag mixed ratio, while the frost resistance and softening coefficient change oppositely. When the replacement rate of recycled coarse aggregate is 100 % and the mix ratio of fly ash and slag is 3 : 1, the compressive strength is 11.77 MPa, the flexural strength is 3.89 MPa, the softening coefficient is 0.99, the water absorption rate is 0.7 %, the mass loss rate after 50 freeze-thaw cycles is 2.2%, and the loss rates of compressive strength and flexural strength are 10.2% and 13.9% respectively, which meet the requirements of load-bearing and durability in severe cold regions and can be used as a recommended mix ratio. Microscopically, alkali excitation promotes the secondary hydration of the composite cementitious materials, generates more hydration products to optimize internal pores, and the concrete structure is dense. With the increase of the number of freeze-thaw cycles, the number of pores in the block gradually increases, and the micropores and mesopores gradually derive into large pores and fissures, and the performance of the block deteriorates. Based on the performance-cost-carbon emission analysis, 100 % recycled coarse aggregate is not conducive to low-carbon emission reduction. The recommended mix ratio of mixed recycled aggregates and active admixtures has a carbon emission reduction rate of 31.03%.