A Novel Method for Improving Segregation Resistance of Cement Asphalt Mortar

Abstract

Cement asphalt mortar (CA mortar) is the key component in the structure of Shinkansen slab track and serves as the elastic shock-absorber. CA mortar is a fluid mixture suitable for placing in structures without vibration. CA mortar development must ensure a good balance between fluidity and stability. Hydrophobically associating watersoluble polymers not only have the unique advantage of segregation resistance but also good properties of fluidity. The fluidity and segregation tests show that by adding hydrophobic associative polymer the degree of segregation of CA mortar is reduced without sacrificing the fluidity and workable time. The rheological test of CA mortar shows that the addition of hydrophobic associative polymer increases the viscosity and shear stress at low shear rates, but the viscosity and shear stress drops at high shear rates, imposing large resistances which alleviate the extent of segregation of CA mortar. The results show that hydrophobic associative polymer could be used successfully in producing CA mortar with reduced segregation potential.