FREEZ-THAW CYCLE TEST AND A DAMAGE MECHANICS MODEL FOR RECYCLED CONCRETE

Aggregate obtained by breaking wasted concrete is called recylcled aggregate. Freeze-thaw cycle tests were carried out on recycled aggregate concrete (RAC) containing 40% of recycled coarse aggregate. Mixed with polypropylene fiber and gas-lifting water-reducing (GLWR) agent, its frost resistance durability and inner damage distribution were also analyzed. It is shown that frost resistance rating of F200 can be achieved from C30 RAC by mixing polypropylene fiber and GLWR-agent. The mixture is also effective in preventing freeze-thaw damage deterioration, where GLWT-agent was more effective. A freeze-thaw damage mechanics model was then established. And predictions from the model agree well with the actual engineering observations.