Study On Application Of Silicone Rubber In Stay Cable And Property Of Silicone Rubber Based Composites

Sheath is an important part of stay cable.After a long period of use,sheath is prone to age,crack and loss the protection of steel strand.While addition-cured room temperature vulcanized silicone rubber(RTV silicone rubber)is a kind of polymer materials with excellent aging resistance properties,therefore,this thesis explores the possibility of RTV silicone rubber as sheathing compounds for stay cable through a series of experiments.There are a lot of studies on graphene/RTV silicone rubber composites.Lots of studies show that graphene can improve the mechanical,electrical and other properties of silicone rubber.But the production of graphene is complex and expensive,which lead to the extremely high cost and low possibility of large-scale application of graphene/silicone rubber composites.Both graphene nanosheets(GNSs)and graphite nanoparticles(GNPs)are graphene series products.Compared to graphene,GNSs and GNPs are easy and cheap to prepare,which lead to the possibility of large-scale application of them.There is little study on adding GNSs or GNPs into RTV silicone rubber at present.So,this thesis focuses on preparing GNSs/RTV silicone rubber composites and GNPs/RTV silicone rubber composites,at the same time,studing the properties of them.Main contents and conclusions are included as follows:Studying whether RTV silicone rubber can be used as sheathing materials for stay cable.First,silicone rubber specimens are prepared in the laboratory.Then,refering to the test items in the current standard of polyethylene sheathing for stay cable,the hardness and mechanical properties of silicone rubber are tested,and the hot air aging,UV(ultraviolet)aging and ozone aging experiments of silicone rubber are designed and carried out.The study concludes that the UV aging and ozone aging resistance of RTV silicone rubber is excellent,and it has the possibility to use as sheathing materials for stay cable.Studying the properties of GNSs/RTV silicone rubber composites.First,the composites are prepared by mechanical blending.Then,the microstructure of composites' cross section is analyzed,hot air aging and UV aging properties of the composites are tested.At last,the study concludes that the mechanical properties of GNSs/RTV silicone rubber composites are not very good,but the hot air aging and UV aging properties of the composites are excellent.Studying the properties of GNPs/RTV silicone rubber composites.Preparation methods and test items of GNPs/RTV silicone rubber composites are same to GNSs/RTV silicone rubber composites.The study concludes that GNPs has little effect on the mechanical properties of RTV silicone rubber,but it can improve the hot air aging and UV aging properties of RTV silicone rubber effectively.