Experimental Study on Impermeability of Recycled Concrete and Its Security Measures

Recycled concrete specimens were prepared according to different fly ash content and water-cement ratio. These specimens were respectively cured for 28d, 60d and 90d.The influence of water-cement ratio, concrete age and fly ash content on the impermeability of recycled concrete was researched through impermeability experiment. On equal terms, the result shows that the average seepage height of recycled concrete is higher than common concrete. The average seepage height increases with the increasing of water-cement ratio, but decreases with the increasing of fly ash content and concrete age. With the increasing of concrete age, the average seepage height of fly ash recycled concrete is higher than that without fly ash. Concrete age and fly ash are play a double role in improving impermeability of recycled concrete. Average seepage height of recycled concrete after treatment is much lower than untreated concrete, and the average seepage height of recycled concrete which age is 60d decreases the biggest. Proper reduction of water-cement ratio and fly ash content, increasing concrete age, pickling of recycled aggregate and other measures can effectively improve recycled concrete impermeability. Fly ash improve impermeability of recycled concrete is better than other three factors.