表观密度对聚氨酯泡沫固化材料力学性能的影响

Effect of Apparent Density on Mechanical Property of Polyurethane Foam Solidified Material

为深化聚氨酯固化道床的研究,通过调整用水量控制聚氨酯泡沫固化材料的表观密度,研究表观密度对聚氨酯泡沫固化材料拉伸性能、撕裂性能、压缩性能和黏结性能的影响,并利用扫描电子显微镜观察聚氨酯泡沫固化材料的泡孔结构。结果表明：聚氨酯泡沫固化材料的表观密度直接影响其泡孔结构,随着表观密度的增加,泡孔数量及大孔数量均减少,而其拉伸强度、断裂伸长率、撕裂强度、压缩强度均呈线性增加,黏结强度逐渐增大。因此,综合考虑技术性和经济性,对碎石道床承载力和稳定性有更高要求的重载铁路而言,宜采用表观密度为165~200kg·m-3的聚氨酯泡沫固化材料;聚氨酯泡沫固化材料能够与混凝土和道砟石良好黏结,且相同表现密度下聚氨酯泡沫固化材料与混凝土的黏结强度高于其与道砟石的黏结强度。

For further research on the polyurethane solidified ballast bed,the effect of the apparent density adjusted by changing water consumption on the tensile property,tear property,compressive property and adhesive property of polyurethane foam solidified material was investigated,and the cell structure was observed by SEM.Results show that the apparent density of polyurethane foam solidified material directly affects its cell structure.The amount of both the cell and macroporous decreases,and the tensile strength,tear strength,compression strength and the elongation at break linearly increase with the increase of apparent density,and so does the adhesive strength.Therefore,when the technical and economic conditions are considered together,designers should use the apparent density of 165~200kg·m-3 polyurethane foam to solidify the crushed stone ballast bed of heavy haul railway,whose bearing capacity and stability requires much higher.In addition,polyurethane foam solidified material can be well adhered with concrete and ballast.Under the same apparent density,the adhesive strength of polyurethane foam solidified material with concrete is greater than that of polyurethane foam solidified material with railway ballast.