重载铁路路基聚氨酯防水层工艺性试验研究

Study on Processability Test of Polyurethane Waterproof Layer for Heavy Haul Railway Subgrade

依托包神重载铁路瓷窑湾站翻浆冒泥整治项目,提出在基床表层增加厚5~8 cm的聚氨酯胶凝级配碎石复合半刚性防水层的整治方案。通过室内试验与现场工艺试验确定聚氨酯胶水的主要材料配比,研究了聚氨酯胶凝级配碎石的防水性能和力学性能,并通过现场行车测试验证了整治效果。结果表明:本工点采用的聚氨酯胶水主要成分由聚醚A、聚醚B、PM200、1,4-丁二醇、二甲苯等构成,适用于本工况的最优质量比为30.0∶10.0∶18.0∶5.4∶5.0;聚氨酯胶水掺量为9%时,聚氨酯胶凝级配碎石混合料渗透系数处于不透水量级;常温条件下聚氨酯胶凝级配碎石抗压强度达15.3 MPa,且受水的影响程度小;回弹模量随着温度的增加呈降低趋势,温度为80℃时回弹模量仍大于300 MPa;聚氨酯胶凝级配碎石复合半刚性防水层具有良好的防水和减振效果,且后期沉降保持稳定。

Based on the treatment project of mud pumping in Ciyaowan station of Baoshen heavy haul railway,the treatment scheme of adding polyurethane cementitious graded crushed stone composite semi-rigid waterproof layer with thickness of 5~8 cm was proposed.Through indoor test and field process test,the main material ratio of polyurethane glue was determined,the waterproof performance and mechanical performance of polyurethane cementitious graded crushed stone was studied,and the treatment effect was verified by field driving test.The results show that the main components of polyurethane glue used in this project are polyether A,polyether B,PM200,1,4-butanediol,xylene,etc.,and the optimal mass ratio suitable for this working condition is 30.0∶10.0∶18.0∶5.4∶5.0.When the content of polyurethane glue is 9%,the permeability coefficient of polyurethane cementitious graded crushed stone mixture is in the order of impermeability.At normal atmospheric temperature,the compressive strength of polyurethane cementitious graded crushed stone is 15.3 MPa,and it is less affected by water.The resilient modulus decreases with the increase of temperature,and the resilient modulus is still greater than 300 MPa at 80℃.The polyurethane cementitious graded crushed stone composite semi-rigid waterproof layer has good waterproof and damping effect,and the later settlement remains stable.