Estimation of the Dynamic Characteristics of the Foam Concrete

Dynamic properties of the building materials are not often under investigation because of complexity and difficulty of the dynamic problems, which need to be solved. Foam concrete (FC) is a material that has wide application and utilization in the civil engineering structures. FC is a mixture of cement, water, additives and technical foam and principle of fabrication is well known for more than 30 years. Currently, it is mainly used in the floor structures of the buildings, thus static parameters are investigated. Its usability can be much wider thanks to its specific properties. A research aimed at the application of the foam concrete in the pavement structures takes place at our workplace. FC could be utilized as a sub-base layer at the road reconstructions, excavations or as a structure layer of the new pavements. This paper presents the preliminary outputs of the experimental and numerical analyses of the selected dynamic properties of the FC. Results were obtained from the dynamic hammer testing and the Finite Element (FEM) simulation as a background for the design procedure of the pavement structures. Relevant dynamic parameters such as dynamic modulus of elasticity at low strain or damping parameters were determined in this article. This paper is also aimed at the estimation of the Rayleigh damping coefficients. For the Rayleigh damping coefficients, a half-power bandwidth method was selected. Conclusions indicate some dispersion of the observed quantities and further testing and analysis to increase the reliability of the determined characteristics is required. Obtained dynamic parameters will be a background for the pavement design using the FC.