物理化学强化对再生混凝土收缩性能影响

Influence of Physical and Chemical Enhancement on Shrinkage Performance of Recycled Concrete

根据《混凝土用再生粗骨料》(GB/T 25177-2010),废弃混凝土经简单破碎、一次颗粒整形和二次颗粒整形后分别制得II类再生粗骨料、准I类再生粗骨料和I类再生粗骨料,并将三类再生粗骨料在浓度6%的有机硅烷防水剂中进行24h化学浸渍处理,得到三类物理化学强化再生粗骨料。分别研究不同品质物理化学强化再生粗骨料和不同取代率(ф_z=0、50%、100%)取代天然骨料对再生混凝土的收缩性能的影响。结果显示:再生粗骨料混凝土收缩性能为:SA-SI再生粗骨料混凝土>FA-SI再生粗骨料混凝土>SBA-SI再生粗骨料混凝土,且均优于普通混凝土;SBA-SI、FA-SI和SA-SI再生粗骨料混凝土的收缩率均随着ф_z的增大而减小。

According to《 Recycled coarse aggregate in concrete 》（ GB / T 25177- 2010）,the waste concrete is simply crushed to II class recycled coarse aggregate,firstly reshaped to I class- to- be recycled coarse aggregate in physical strengthening and twice reshaped to I class recycled coarse aggregate in physical strengthening. Three kinds of recycled coarse aggregate are marinated in organic silicon waterproof agent of concentration 6% for 24 h chemical treatment and then three kinds of recycled coarse aggregate of physical and chemical enhancement canbegot.The influence on coefficient of the chloride migration and substitution rate（ф_z= 0,50%,100%） of recycled coarse aggregate of physical and chemical enhancement to replace natural aggregate was studied. The results show that,the order of shrinkage performance different on recycled coarse aggregate is SA- SI recycled coarse aggregate concrete FA- SI recycled coarse aggregate concrete SBA- SI recycled coarse aggregate concrete,which is better than ordinary concrete. With the increase of the substitution rate,the coefficient of the shrinkage performante of SBA-SI、FA- SI 和 SA- SI recycled coarse aggregate concrete reduces.