Enhancing vibration reducibility of cementitious composites by incorporating microparticles and microvoids: experimental and simulation studies

Abstract

Traffic vibration is one of the main vibration sources in people’s daily life, which can adversely affect people’s health and the service life of building structures. Although many studies have developed many different kinds of methods and measures to reduce traffic vibration, no practical and effective method is from the construction and building materials fields. The experimental study of this work focuses on investigating the damping behavior and mechanical properties of cementitious composites that contain hollow glass microsphere, cenosphere, or graphite flakes with different size and volume fractions. These microparticle materials work as fillers in cementitious composites. The damping ratio test is conducted to evaluate the vibration reducibility based on the half-power bandwidth method. Compressive and flexural strength tests are conducted to investigate the effect of different filler materials on mechanical properties. Experimental work is very important for finding better filler material and its better volume fraction; on the other hand, numerical analysis can efficiently estimate the damping capacity and reduce the usage of materials. Therefore, this work also focuses on finding methods to simulate the damping behavior of cementitious composites. Moreover, a new type of sustainable cementitious composite is developed to improve vibration reducibility by increasing porosity while alleviating the environmental problem and keeping the compressive strength. Similarly, the damping ratio test and compressive strength test are conducted to evaluate the vibration reducibility and structural resistance, respectively. CO2 emission evaluation is conducted to prove that the new type of material can reduce greenhouse gas emissions. The experimental work finds that microparticles with a hollow structure can improve the damping ratio with the increase in the volume fraction, but compressive and flexural strength decreases significantly except graphite flakes. Graphite flakes can improve the damping ratio with a relatively low volume fraction while maintaining compressive strength and stiffness at an acceptable level and increasing flexural strength. Besides, the simulation works reveal that the analytical results correspond well to the experimental results, although all materials are assumed to be viscoelastic or elastic. Furthermore, the new type of sustainable materials can improve the damping ratio by increasing the porosity to 30% while maintaining the compressive strength at 30 MPa. It can also be a promising material for improving vibration reducibility. Although the developed materials were proven to be effective for vibration reduction by experiments, no existing study investigated the effect of vibration-reducible materials at a structural level under railway loading. Based on the FE model and acoustic-solid interaction module, this study developed a numerical method to predict the vibration, sound pressure level, and structure-borne noise within a building near the urban railway system. This is an efficient method that can be used to investigate the effect of vibration-reducible on the vibration and sound reduction within a building structure. From the numerical analysis results, it can be found that SGF has a relatively better effect on vibration, sound, and structure-borne noise reduction than other vibration-reducible materials. Besides, the parametric study revealed that higher elastic modulus, higher damping ratio, and lower density are effective for vibration and sound reduction.