台背回填矿粉气泡混合轻质土性能试验研究

通过对5种矿粉掺量的气泡混合轻质土（FCB）进行抗压强度、干缩变形及抗冻性能试验研究，结合某高速公路高架桥桥台台背回填工程，对矿粉FCB的实际应用效果及经济性进行了探讨。结果表明:FCB的抗压强度随矿粉掺比增大而逐渐降低，矿粉掺比低于30 %的FCB抗压强度能满足重交通条件下高等级公路路床填料强度设计要求，矿粉掺比为30 %的FCB抗干缩性和抗冻性良好。实际工程中，采用的矿粉掺比为30 %，其28天抗压强度达0.81 MPa，桥台台背顶面的平均工后沉降量小于设计规范要求的沉降标准，矿粉FCB较挡墙支护+石灰改良土施工更为经济。

Experimental Study on the Properties of Foam Concrete Banking with Mineral Powder for Backfilling behind Abutment

In this paper, the compressive strength, dry shrinkage deformation and frost resistance of five kinds of foam concrete banking (FCB) with mineral powder content are tested and studied. Combined with the highway viaduct abutment backfill project, the practial appliction effect and economy of FCB with mineral power are discussed. The result shows that the compressive strength of FCB gradually decreases with the increase of mineral powder blending ratio. The compressive strength of FCB with mineral powder blending ratio of less than 30 % meets the design requirements of high-grade highway bed filler strength under heavy traffic conditions, and the FCB with mineral powder blending ratio of 30 % has good drying shrinkage and frost resistance. In the actual project, the blending ratio of mineral powder in FCB used is 30 %, the compressive strength of 28 days reaches 0.81 MPa. The average post-construction settlement of the top surface of the abutment back is less than the settlement standard required by the design specification. It is more economical than retaining wall support + lime-improved soil construction.