足尺再生混凝土柱小偏压受力性能试验研究

Experimental Study on Compression Performance of Full-scale Recycled Aggregate Concrete Columns under Small Eccentric Loadings

再生混凝土柱受压性能是再生混凝土框架抗震设计的关键。进行了3个足尺再生混凝土柱试件小偏心受压性能试验,采用单向重复加载。各试件纵筋及箍筋配筋相同,3个试件粗骨料取代率分别为0,50%,100%,细骨料为普通砂,粗骨料取代率0的试件为普通混凝土试件。分析了各试件的破坏形态、承载力、刚度、延性、混凝土应变、钢筋应变。研究表明:小偏心受压下,再生混凝土柱的损伤过程及破坏形态与普通混凝土柱类似,两个再生混凝土试件承载力与普通混凝土试件接近,刚度略小于普通混凝土试件,粗骨料取代率50%的试件延性较好,粗骨料取代率100%的试件延性与普通混凝土试件相当,可近似参照现行规范进行再生混凝土柱小偏心受压承载力设计。

Compression performance of recycled concrete columns is one of the key problems in the seismicdesign of recycled concrete frame. Three full-scale reinforced recycled concrete columns were tested underrepeated small eccentric loading. The longitudinal reinforcement and stirrup reinforcement details of allspecimens are same. The recycled coarse aggregate replacement ratio are 0,50%, 100%. The fine aggregateis common sand. The specimen with coarse aggregate replacement ratio of 0 uses normal concrete. Thecompression failure characteristics, load-bearing capacity, bending stiffness, ductility and strain distributionregularities of rebar and concrete were analyzed. Research shows that,the damage evolvement process, failurecharacteristics of reinforced recycled concrete columns under repeated small eccentric loading are similar tothose of normal reinforced concrete columns. The bearing capacity of two recycled concrete specimen is closeto those of normal concrete specimen. The bending stiffness is slightly smaller than normal concrete specimen.The ductility of specimen with recycled coarse aggregate replacement ratio of 50% is better. The ductility ofspecimen with recycled coarse aggregate replacement ratio of 100% is close to normal specimen. To calculatethe load-bearing capacity of reinforced recycled concrete columns under repeated small eccentric loading canapproximate refer to current concrete specification.