摘   要：研究了石粉含量对轨道工程用C20、C35、C50机制砂混凝土性能的影响及石粉含量的合理范围。结果表明：对于工作性和抗压强度，机制砂混凝土的强度等级越高，石粉的最佳含量越小，C20机制砂混凝土的石粉含量宜为10%~20%，C35宜为5%~10%，C50宜为5%以内；对于早期抗裂性能，C35机制砂混凝土的石粉含量宜控制在3%~7%，C50宜控制在5%以内；对于抗氯离子渗透性能，C35机制砂混凝土的石粉含量宜控制在5%~15%，C50机制砂混凝土的性能受石粉含量的影响较小；对于抗冻性能，当石粉含量在5%以内时，C35机制砂混凝土的抗冻性能变化不明显，超过5%后，抗冻性能下降，石粉含量对C50机制砂混凝土抗冻性能的影响不明显。

Abstract: The effect of stone powder content on the performance of C20, C35 and C50 manufactured sand concrete for rail transit engineering was studied, and the reasonable range of stone powder content was determined. The results show that for workability and compressive strength, the higher the strength grade of manufactured sand concrete, the smaller the optimal content of stone powder. The stone powder content of C20, C35 and C50 manufactured sand concrete should be 10%~20%, 5%~10%, and within 5%, respectively. For early crack resistance, the stone powder content of C35 manufactured sand concrete should be 3%~7%, and C50 should be controlled within 5%. For the resistance to chloride ion penetration, the stone powder content of C35 manufactured sand concrete should be controlled within 5%~15%, and the performance of C50 manufactured sand concrete is less affected by the content of stone powder. For frost resistance, when the stone powder content is within 5%, the frost resistance of C35 manufactured sand concrete does not change significantly. After exceeding 5%, the frost resistance decreases, and the effect of stone powder content on the frost resistance of C50 manufactured sand concrete is not significant.