陶粒轻骨料与普通混凝土的黏结剪切性能

Interfacial Shear Performance of Ceramsite Lightweight Aggregate and Normal Concrete Cold Joint

设计制作了双面直剪型陶粒轻骨料混凝土与普通混凝土叠合浇筑试块并进行剪切破坏试验,发现各组试块的最终剪切破坏面层不同程度地由两侧混凝土及初始浇筑面层共同组成.为此,给出了具有内部分层式速度间断面的剪切破坏机构模型,并选用Mises屈服条件及Coulomb剪破条件,根据塑性极限分析原理建立了2种混凝土黏结层剪切破坏强度的解析解.结果表明:陶粒轻骨料混凝土与普通混凝土叠合浇筑时,考虑浇筑结合面处理方式、浇筑间隔时间及法向力影响的最终剪切破坏遵循Mohr-Coulomb强度准则.

The composite sandwiching block of ceramsite lightweight aggregate concrete and ordinary concrete were designed,and the interfacial bonding shear strength was tested.The final shear failure surface layer was composed of the two kinds of concrete materials and the initial casting interface with different quantity.A shear failure model for the casting bonding interlayer of the lightweight aggregate concrete and ordinary concrete was proposed,in which the multi-layer velocity discontinuity was supposed.The analytical solution for the shear strength of the casting bonding interlayer was deduced based on the Mises yielding condition and Coulomb shear failure condition.The model relates the final shear failure strength to the forming,the developing of the shear failure interface and the material properties of the concrete and the initial casting interlayer.At the same time,the analytical solution clearly indicates that the final shear failure for the composite casting of lightweight aggregate concrete and ordinary concrete follows the Mohr-Coulomb strength rule considering the influence of the casting interval time,the preparing method of the casting interface and the normal force.