DEVELOPMENT OF DAMPING MEASURING APPARATUS AND EXPERIMENTAL RESEARCH FOR FIBER REINFORCED CONCRETES

摘要

Fibers and polymers as the admixtures in the concrete may improve greatly the damping ability of concrete materials. In this paper, Firstly the damping relationships of viscoelastic materials on three-point support were given at sinusoidal alteration excitation. Secondly, the damping measuring apparatus for large-scale materials such as concretes were firstly developed at home and abroad. Thirdly, the loss tangent and storage modulus of 6 kinds' fiber reinforced concrete in different ratios were measured at frequency (0.5～2.0Hz) by this apparatus. Finally, the mechanism of fiber damping reinforced was initiatively discussed. The experiments show that polymers and fibers prior to incorporation in the concrete resulted in composites exhibiting increases of loss tangent by 80～200% relative to the value of the concrete without any admixtures. The improvement of viscoelasticity and the interfaces friction for plain concrete by polymers and fibers contribute to the damping.