Experimental Study On Biomimetic PVA Fiber Reinforced Cement Composite Slabs

As a trend of the new era, the bionic will become an important means to design new type of building materials. In this paper,The concept of bionics had been invited into the design of the PVA fiber reinforced cement composite slabs. It was designed to a “CFRP+rubber+ PVA fiber reinforced cement slabs” structure, thus the cladding structure could improve the toughness and meet the requirements of protection engineering in the future.In this paper, the punching shear test of PVA fiber reinforced cement slabs with different contents(0%, 1%, 1.5% and 2%) was carried out. The result showed that its breakage transfered from brittleness to plasticity with the incorporation of PVA fibers. Interestingly, it had no significant effect on the maximum load, and the optimum PVA fiber content was 2%. In addition, the elasto-plastic analysis was conducted in this paper. The analytical method turned out to meet the need of engineering requirement.A penetration test test with the different impact velocity(1m/s, 2m/s, 3m/s, 3.5m/s, 4.5m/s) of PVA fiber reinforced cement slabs was conducted. Compared with the punching shear test, the bearing capacity increased, however, the displacement at maximum force and the energy consumption reduced. Interestingly, the energy consumption increased with the increase of the velocity under the hammer impact test.The uniaxial tensile tests of CFRP under different ways(warp and fill) and different layers(one layer and two layers) were finished. The mechanical properties of the CFRP were analyzed. The tests showed that the failure of CFRP was nonlinear and brittle. Compared to the fill direction, the warp tensile strength and elastic modulus of CFRP(one layer and two layers) was increased by nearly 20%. And compared to two layers of CFRP, one layer ’s strength and elastic modulus of CFRP(warp and fill) was also increased.The load displacement curve of rubber was obtained by indentation test. The plane symmetric finite element model for rubber was established by The Ansys Workbench software, and the Mooney-Rivlin model was used to calibrate the parameters of rubber material. The results showed that the calibration parameters were reliable and have high accuracy.The punching shear test on the bionic composite slabs under different overlay mode was conducted. The results showed that the maximum load of the composite slabs increased with the increase of the number of CFRP layers when covered with the whole CFRP. In course of failure, the interface between rubber and PVA fiber reinforced cement slabs has been stripped off. While covered with the CFRP scale, it was a relatively weak constraint between rubber and PVA fiber reinforced cement slabs, the maximum load was lower, but there was no interface stripping. It had good stability.