Study On Mechanical Properties And Sound Absorption Properties Of Glass Fiber Reinforced Cement-based Composites

With the rapid development of society,the impact of noise in all aspects on people is more and more obvious.In order to have a comfortable living environment,research on building materials with sound-absorption properties has become very necessary.At present,the research on the sound absorption performance of cement-based sound absorption materials is very limited.In this thesis,the mechanical properties and sound absorption properties of glass fiber reinforced cement-based composites(GFRCC)were studied and the two properties of GFRCC were analyzed macroscopically and microscopically.The optimized proportion of GFRCC for mechanical properties was obtained by orthogonal experiment,that is,0.3 for water-cement ratio,1:1.3 for cement-sand ratio and 0.4% for glass fiber volume fraction.Based on the optimized proportion,the effects of mineral admixtures on the mechanical properties and sound-absorbing properties of GFRCC were investigated by means of mechanical properties tests and function transfer method,respectively.The results showed that the mineral admixture had an obvious influence on flexural and compressive strength of GFRCC.The flexural and compressive strength of GFRCC decreased with fly ash content increasing and increased with silica fume content increasing.With the same content of fly ash,flexural and compressive strength of GFRCC increased with curing age increasing.The effect of complex mineral admixtures on the mechanical properties of materials has an additive effect.The mineral admixture had an influence on the sound absorption coefficient of GFRCC.The sound absorption coefficient of GFRCC was firstly increased and then decreased with fly ash content increasing.When the content was 20%,the peak value was reached;the sound absorption coefficient of GFRCC was increased with silica fume content increasing;with the same content of fly ash,the curing age had no effect on the sound absorption coefficient of GFRCC;the influence of complex mineral admixtures on the sound absorption performance of the material have an additive effect.In this thesis,the mercury pore structure of GFRCC was investigated by mercury intrusion porosimetry to study the relationship between macroscopic phenomena and microscopic pore structure.It was concluded according to experiments that the mineral admixture had a significant effect on the microstructure of GFRCC.The coarse pores in GFRCC were filled by fly ash and silica fume,and the pore size distribution in GFRCC could be improved.With the same content of fly ash,the mesopore structure of GFRCC was improved with curing age increasing.Meanwhile,the internal pore structure of GFRCC had no obvious influence on the sound-absorption performance of the material.