不同因素对水泥稳定碎石力学性能与疲劳特性的影响

Influence of Different Factors on Mechanical Properties and Fatigue Characteristics of Cement Stabilized Macadam

为了探究不同因素对水泥稳定碎石材料力学性能与疲劳特性的影响程度,以及水泥稳定碎石材料力学性能与疲劳特性随不同因素增长的变化规律,选取水泥剂量、压实度、含水率、筛孔(19,9.5,4.75 mm)通过率共6个因素对水泥稳定碎石材料设计正交试验,采用极差分析法研究了各因素对水泥稳定碎石不同龄期下力学性能的影响程度及变化规律。同时对不同水泥剂量的水泥稳定碎石材料进行了疲劳试验,得到了相应的疲劳方程。结果表明:混合料的力学性能在养生龄期前28 d时增长较快,因此混合料力学性能的形成主要集中在前28 d;水泥剂量的极差值(R值)均远大于其他因素,而3种筛孔通过率的R值均较低,说明水泥剂量对混合料的力学性能影响程度最大。因此,应当严格把控混合料的水泥剂量、压实度以及4.75 mm通过率以保证施工质量;水泥剂量及4.75 mm通过率是影响90 d无侧限抗压强度的主要因素,而60 d无侧限抗压强度的主要影响因素是水泥剂量和压实度。因此当把控路面某项力学性能指标时,应当针对该指标所要求的龄期控制对其影响最大的因素。

To explore the influencing degree of different factors on mechanical properties and fatigue characteristics of cement stabilized macadam materials,as well as to explore the rule of mechanical properties and fatigue characteristics of cement stabilized macadam materials varying with the growth of different factors,the 6 factors,including cement dose,compaction degree,moisture content,19 mm screen pass rate,9.5 mm screen pass rate and 4.75 mm screen pass rate,were selected for orthogonal test on cement stabilized macadam materials.The influence of various factors on mechanical properties of cement stabilized macadam at different ages was studied by using range analysis method.Simultaneously,the fatigue test of cement stabilized macadam materials with different cement dosages were carried out.The corresponding fatigue equations were obtained.The result indicates that the mechanical properties of mixture increase rapidly in the first 28 d of curing age,so the formation of mechanical properties of mixture is mainly concentrated in the first 28 d.The range value(R value)of cement dosage is much higher than other factors,and the R values of 3 sieve penetration rates are low,indicating that the cement dosage has the greatest influence on mechanical properties.Therefore,the cement dosage,compaction degree and 4.75 mm passing rate of mixture should be strictly controlled to ensure the construction quality.Cement dose and 4.75 mm passing rate are the main factors affecting 90 d unconfined compressive strength,while the main factors affecting 60 d unconfined compressive strength are cement dose and compaction degree.Therefore,when controlling the certain mechanical performance indicator of pavement,the age required by the indicator should be targeted according to the factors that have the greatest influence.