Effect of Polymer Emulsion on Properties of Self-compacting Concrete
The effects of ethylene-vinyl acetate copolymer emulsion,styrene-acrylic emulsion and styrene-butadiene rubber emulsion on the workability,static stability,mechanical properties and volume stability of self-compacting concrete were studied.The results shows that all three polymer emulsion can increase the expansion time T500 of self-compacting concrete,reduce the height difference of J ring barrier,penetration and drying shrinkage rate of self-compacting concrete,and significantly improve the bond strength of self-compacting concrete.It can also meet the requirement of 28 d bonding strength greater than 2.0 MPa in Repair Mortar for Concrete Structure of High speed Railway(Q/CR 659-2018),but it will reduce the compressive strength of self-compacting concrete to varying degrees.The self-compacting concrete mixed with ethylene-vinyl acetate copolymer emulsion has the smallest reduction in compressive strength,and its strength can meet the strength requirements of C55 concrete,Therefore,this self-compacting concrete can be used for repairing the void in the arch ribs of steel tube concrete arch bridges.