Experimental Research On Compression Performance Of Recycled Aggregate Concrete Columns

Three issues are maily discussed in this paper, which including the possibility to recycle C80 high performance concrete and the material properties of recycled aggregate concrete; experimental study on the compression performance of recycled aggregate concrete columns; and advantages of recycled aggregate concrete in concern with the effects of economy and environment. They are described in the following.1) Specimens with C80 high performance concrete were cast in laborotary. They were crushed to produce recycled coarse aggregate. Under the concdition of similar mix proportions, the recycled concrete was then mixed with different replacement percentages of recycled coarse aggregates (i.e., 30%, 50%, 70% and 100%). The compressive strength, the flexural strength and the elastic modulus of recycled concrete were tested and the ultrasound inspection, the rebound test as well as the water penetration test were also undertaken. The test results show that it is possible to reuse the crushed C80 high performance as recycle coarse aggregates. Compared with the original C80 concrete, however, the compressive strength left only 80%, the flexural strength left about 55%, and the elastic modulus was decreased with the increase of recycled coarse aggregate replacement percentage. It should be noted that the water penetration ability of recycled concrete seems better than the original concrete.2) On the basis of testing on 12 columns with C30 recycled concrete, the compression performance of recycled concrete columns with different replacement percentages (i.e., 0, 50%, and 100%) of recycled coarse aggregate and different eccentricities (i.e., 0mm, 30mm, 82mm, and 100mm) were investigated. The failure patterns of the recycled concrete columns were found to be similar with those of normal concrete columns. Based on the analysis of experiment results, it is proved that it is feasible to apply the current design standard for load capacity calculation of recycled aggregate concrete columns.3) Finally, the recycled aggregate concrete was comprehensivly analyzed in the aspects of both economy and environment. It was concluded that the recycled aggregate concrete has obvious advantages in theses aspects, which matches the sustainable development strategy of our country.