Yanhui Zhong

Numerical and Experimental Studies of Diffusion Law of Grouting with Expansible Polymer

AbstractPolyurethane has been widely used as new chemical grouting material. Expansion characteristics caused by chemical reactions make polymer grout different from other types of grout. To throw ...

Method for Identifying the Depth of Voids beneath Rigid Pavement Slabs Based on GPR

According to radar wave propagation characteristics in pavement structures, the impacts of depth of multiform voids upon radar reflected signals are studied by establishing the model of Ground Penetrating Radar (GPR) electromagnetic wave propagation in rigid pavement with voids. Meanwhile, the method of determining the depth of voids beneath rigid pavement slabs is presented. This paper provides an important technical support for identifying the depth of voids beneath slabs in rigid pavement based on the GPR reflected signals.

Comparison and Analysis Method for Identifying the Voids beneath Concrete Pavement

Voids beneath slab is one of the common distresses of cement concrete pavement, which seriously influences the service ability and the tired life-span of the cement concrete pavement, and the Falling Weight Deflectometer(FWD) gets more and more applications on identifing the voids beneath the cement concrete slab because of its advantages such as speediness, nondestructiveness, etc. The formula for calculating the stresses, strains and deflections of the PCC pavement slab are deduced for different void shapes, and the displacement calculation models of the slab are established for winkler foundation, then the displacements for different void size and position are solved, and also the deflection basin curves are simulated. Through contrasting the deflection curves with voids and without voids beneath slab, the comparison analysis method for identifying the voids beneath slab is put forward based on the FWD measured deflection data. By applying this method in engineering, it is showed that it is a brief and effective method for evaluating the voids for PCC pavement. The achievements of this paper offer a new method and theoretic support for identifying the voids of concrete pavement.

Theoretical Research on Three Points Regression Method for Identifying the Voids of Concrete Pavement

The void model with the consideration of contact is established based on the mechanism of void development. The concept of Contact Compensation is first put forward, and it is pointed out that the Contact Compensation is the essential reason to result in the intercept of relationship between load and deflection in the three points regression method for identifying the voids of concrete pavement. The contact condition between concrete slab and the base in void region is analyzed by using nonlinear finite element method. The results show that the correlation of Contact Compensation and slope-difference is very good. The achievements will be the base for quantificationally identifying the voids of concrete pavement.