【摘要】 为促进石屑在道路基层中的应用，利用石屑替代细集料制备水泥稳定碎石混合料，并掺入废弃磷石膏改善混合料的抗裂性能。采用响应面法（Box-Behnken设计）,以石屑替代率（质量分数）、磷石膏和水泥掺量（质量分数）作为自变量，以水泥稳定碎石混合料的7 d抗压强度、7 d劈裂强度、28 d干缩系数以及平均温缩系数为响应变量建立各自的响应面数学模型，讨论3种自变量对水泥稳定碎石混合料性能指标的影响规律，并优选出石屑最佳替代率、磷石膏和水泥的最佳掺量。结果表明：石屑替代率与水泥掺量的交互作用对混合料各项性能影响最为显著，且当石屑替代率、磷石膏和水泥掺量分别为58.7%、11%和4.9%时，混合料的综合性能最佳；最佳配合比下混合料的7 d抗压强度、7 d劈裂强度、28 d干缩系数以及平均温缩系数分别为5.75 MPa、0.49 MPa、220.8×10^-6、8.45×10^-6℃^-1,预测值和实测值误差不超过2%,模型精准度高；相较于普通水泥稳定碎石，最佳配合比下混合料的收缩系数略有上升，抗压强度和劈裂强度分别提升了23.8%和19%。更多还原

【Abstract】 To promote the application of crushed stone dust in road base courses, cement-stabilized macadam mixtures were prepared by replacing fine aggregates with crushed stone dust, and waste phosphogypsum was incorporated to enhance the crack resistance of the mixtures. Using the response surface methodology（Box-Behnken design）, the replacement rate of crushed stone dust（mass fration）, phosphogypsum content（mass fration）, and cement content（mass fration） were taken as independent variables, while the 7-day compressive strength, 7-day splitting tensile strength, 28-day dry shrinkage coefficient, and average temperature shrinkage coefficient of the cement-stabilized macadam mixture were considered as response variables. Corresponding response surface mathematical models were established to analyze the influence of the three independent variables on the performance indicators of the mixture. The optimal replacement rate of crushed stone dust, and the optimal contents of phosphogypsum and cement were determined. The results indicated that the interaction between the stone chip replacement rate and cement content had the most significant impact on the various properties of the mixture. The optimal comprehensive performance was achieved when the stone chip replacement rate, phosphogypsum content, and cement content were 58.7%, 11%, and 4.9%, respectively. Under the optimal mix proportions, the 7-day compressive strength, 7-day splitting tensile strength, 28-day dry shrinkage coefficient, and average temperature shrinkage coefficient of the mixture were 5.75 MPa, 0.49 MPa, 220.8×10^-6, and 8.45×10^-6 ℃^-1, respectively. The error between predicted and measured values did not exceed 2%, indicating high model accuracy. Compared with ordinary cement-stabilized macadam, the shrinkage coefficients of the optimally proportioned mixture increased slightly, while the compressive strength and splitting tensile strength improved by 23.8% and 19%, respectively.更多还原