The present work aims to study a cement-treated sand through resilient modulus (RM) and fatigue life (N_f) tests. The use of the porosity/cement index (η/C_iv) for the assessment of mixtures cyclic response was investigated for the first time. A uniform fine clean sand was cement-treated with varying amounts of Portland cement content (from 1% to 9%) and compacted with different voids ratios (0.64, 0.70 and 0.78). Increasing porosity or reducing Portland cement content led to RM and N_f reduction. The porosity/cement index (η/C_iv) showed to be suitable to predict the cyclic behaviour of a cement-treated sand considering varying Portland cement contents and dry densities. For the studied sand matrix–Portland cement blend N_f/RM fits η/C_iv according to a power function, revealing a consistent pattern of dependence between these geomechanical properties and that index. Analysis of variance (ANOVA) performed on the results of a factorial experiment considering the effect of porosity and cement content showed both factors are significant in affecting the measured values of the investigated characteristics. By using the η/C_iv, practitioners may choose the amount of cement and the target density appropriate to provide a mixture that meets the fatigue life and average resilient modulus required by their project.

本工作旨在通过弹性模量（RM）和疲劳寿命（N _f）测试来研究水泥处理的砂土。首次研究了使用孔隙度/水泥指数（η / C _iv）评估混合物的循环响应。用不同数量的波特兰水泥含量（从1％到9％）对均匀细腻的清洁砂进行水泥处理，并以不同的空隙率（0.64、0.70和0.78）压实。增加孔隙率或降低波特兰水泥含量导致RM和N _f降低。孔隙率/水泥指数（η / C _iv）被证明适合预测考虑到不同波特兰水泥含量和干密度的水泥处理砂的循环行为。对于所研究的砂基质，波特兰水泥共混物N _f / RM根据幂函数拟合η / C _iv，揭示了这些地质力学性质与该指数之间的一致依赖性。在考虑孔隙度和水泥含量的析因实验结果上进行的方差分析（ANOVA）表明，这两个因素均对影响所研究特征的测量值具有重要意义。通过使用η / C _iv，从业人员可以选择合适的水泥用量和目标密度，以提供满足其项目要求的疲劳寿命和平均弹性模量的混合物。