Kraszewski Cezary, Rafalski Leszek, Gajewska Beata
Road and Bridge Research Institute IBDiM, Instytutowa 1, 03 302 Warsaw, Poland.
Department of Geotechnical Engineering, Institute of Civil Engineering, Warsaw University of Life Sciences, Nowoursynowska 159, 02 776 Warsaw, Poland.
Materials (Basel). 2022 Feb 19;15(4):1561. doi: 10.3390/ma15041561.
Road layers should be properly compacted to obtain an adequate bearing capacity and durability. Both the unbound and hydraulically bound mixtures used in the layers require compaction. After compaction and hardening, soil mixed with a binder acquires mechanical features that unbound soil lacks, including tensile strength () and unconfined compressive strength (). The effect of the compaction ratio () of the low-strength cement-stabilised soils on these features has rarely been investigated. This study investigates the influence of the compaction ratio on the mechanical properties of hardened, stabilised mixtures of medium-grained sand with 5%, 6.5%, and 8% Portland cement. Cement-soil stabilisation tests showed that compressive strength depends exponentially on the compaction ratio, whereas tensile strength and the stiffness modulus depend linearly on the compaction ratio. For tensile strength and the dynamic stiffness modulus, the effect is not statistically significant, and the usual practice of ignoring compaction dependence is justified. For compressive strength, however, the effect is significant, especially when = 98-100%. When the values of and strengths at various were normalised by those at 100%, it was found that mixtures with higher strengths are the least resistant to changes in the compaction ratio. Knowing the percentage by which the value of a given parameter changes with compaction can be extremely valuable in engineering practice.
道路各层应进行适当压实，以获得足够的承载能力和耐久性。各层中使用的未结合料和水力结合料混合物都需要压实。压实和硬化后，与粘结剂混合的土壤获得了未结合土壤所缺乏的机械特性，包括抗拉强度（）和无侧限抗压强度（）。低强度水泥稳定土的压实比（）对这些特性的影响鲜有研究。本研究调查了压实比对含5%、6.5%和8%波特兰水泥的中粒砂硬化稳定混合物力学性能的影响。水泥土稳定试验表明，抗压强度与压实比呈指数关系，而抗拉强度和刚度模量与压实比呈线性关系。对于抗拉强度和动态刚度模量，这种影响在统计学上不显著，忽略压实相关性的通常做法是合理的。然而，对于抗压强度，这种影响是显著的，尤其是当=98 - 100%时。当将不同压实比下的抗压强度值和抗拉强度值按100%时的值进行归一化时，发现强度较高的混合物对压实比变化的抵抗力最小。了解给定参数值随压实变化的百分比在工程实践中可能非常有价值。
