新型硬质聚氨酯泡沫抗压性能及本构关系研究

Research on Foam Compressive Properties and Constitutive Relation of a New Type of Rigid Polyurethane

聚氨酯发泡材料拥有快速早强、轻质等优点,在很多基础设施建筑及修复上都有应用.本文在未浸水与浸水两种条件下,通过对聚氨酯发泡材料2h内的单轴抗压强度进行测试,得到材料的应力-应变曲线,并通过分析认为:曲线无明显的峰值点,随着时间的增加,试样的抗压强度不断增加,并在90min时能达到最大强度95%以上;浸水后试样的抗压强度有10%左右的增幅;试样的强度与密度相关,密度越大,试样的强度越大.通过引入时间特征参数,同时结合试验结果,提出2h内浸水下不同时间内聚氨酯材料的单轴抗压本构模型,验证了时间参数拟合公式的合理性,可为聚氨酯材料在路面修复以及抢险救灾工程的应用提供理论依据.

Polyurethane foam material has the advantages of rapid,early strength,lightweight,and in many applications of infrastructure construction and repair.In this paper,under the condition of drying and soaking,the uniaxial compressive strength is tested within 2 h and the stress-strain curves are also obtained.The experimental results show no obvious peak points,and with the increase of time,the compressive strength increases.After 90 min,the strength can achieve 95%of its maximum strength.Under soaking,the compressive strength increases about 10%.The compressive strength is related to the density,and the greater the density,the greater the strength of the specimens.By introducing time characteristic parameters and combining with the test results,a constitutive model under uniaxial compression is presented for polyurethane materials after 2h soaking.The rationality of the time parameter fitting formula is verified for polyurethane material.The model can provide theoretical basis for the pavement repair and the application of rescue and relief project.