道砟清洁度对聚氨酯固化材料力学性能的影响

采用石粉、煤粉、黏土和机油模拟道砟中的脏污材料,研究脏污材料含量对聚氨酯固化材料与道砟的黏结性能以及固化材料与道砟固结体力学性能的影响,并对黏结界面聚氨酯固化材料的微观形貌进行了分析。结果表明:随着道砟中粉体脏污材料含量的增加,聚氨酯固化材料的黏结强度逐渐降低,粉体脏污材料含量不超过0. 6%时其对聚氨酯固化材料与道砟固结体的力学性能影响不大,与粉体脏污道砟黏结时固化材料的黏结破坏为本体断裂;与粉体脏污材料相比,机油对聚氨酯固化材料黏结性能以及固结体力学性能的影响较大,与油污道砟黏结时固化材料的黏结破坏为界面断裂,且在压缩循环荷载作用下固结体残余变形量较大。综合考虑固化材料的黏结性能、灌注性能和固结体力学性能,道砟中粉体脏污材料含量不宜超过0. 6%,且不宜含有机油。

Influence of Ballast Cleanliness on Mechanical Properties of Polyurethane Curing Material

The dirty materials in ballasts were simulated by stone powder,coal powder,clay and engine oil.The effects of dirty materials content on the bonding properties of polyurethane curing materials and ballasts and the mechanical properties of the solidif ied materials and ballast consolidation were studied,and the micro-morphology of polyurethane curing material on bonding interface was also analyzed.The results show that the bonding strength of polyurethane curing material decreases gradually with the increase of powder dirty material content in ballast,it has little effect on the mechanical properties of polyurethane curing material and ballast consolidation when the content of powder dirty material is less than 0.6 %.The bonding failure of solidif ied material bonded with powder dirty ballast is bulk fracture.Compared with powder dirty materials,engine oil has greater inf luence on the bonding properties of polyurethane curing materials and mechanical properties of the solidif ied materials and ballast consolidation.When bonding with oil dirty ballast,the bonding failure of solidif ied materials is interface fracture,and the residual deformation of consolidation is larger under compressive cyclic loading.Considering the bonding properties, f illing properties of the solidif ied materials and mechanical properties of consolidation,the content of powdered dirty materials in ballasts should not exceed 0.6 %,and the content of engine oil should not be included.