Study On Design,Performance And Dynamics Of Unsaturated Polyester Resin Concrete

Poor high-temperature stability has always been a problem that plagues asphalt mixture pavements.Although many materials have been used to modify asphalt mixtures,most materials have failed to change their viscoelastic nature.Unsaturated polyester resin concrete(UPC)is a high-performance composite material that uses unsaturated polyester(UP)as a binder,curing and cross-linking aggregates and fillers under the action of an initiating system.UPC has the advantages of high compressive strength,strong anti-corrosion performance,high plasticity,fast curing,etc.It has been used in construction,metallurgy and other industries,however,there is less research and application in the road industry.In order to facilitate the popularization and application of UPC in the road industry,this paper studied the design,road performance,microscopic characteristics and curing kinetics of UPC.In order to obtain a bonding material suitable for road UPC,this article conducted a preliminary selection of m-benzene type,o-phenyl type,bicyclic type and bisphenol A type UP.During the mixing and modification of UP,methyl ethyl ketone(MEKP)and benzoyl peroxide(BPO)were used as initiators,cobalt isooctanoate and N,N-diethylaniline were used as accelerators,and hydroquinone was used as a resistance Polymerizer,liquid nitrile rubber(LNBR),carboxyl terminated liquid nitrile rubber(CTBN)and polyvinyl acetate(PAVc)were toughening agents.The two resin ratios were initially selected through the experiment:?1(M-benzene type UP/bisphenol A type UP)resin:BPO:N,N-diethylaniline:hydroquinone=100:1:0.5:0.06;?2(m-benzene type UP/bisphenol A type UP)Resin:MEKP:Cobalt Isooctanoate:Hydroquinone=100:1.5:0.75:0.04.Comprehensive consideration of construction performance and mechanical properties,LNBR modified UP with good compatibility,storage stability,bending,tensile,impact toughness and low temperature creep performance was obtained.Combining the physical and mechanical properties of UP and the aggregate gradation design,a UPC design method based on volume parameters was proposed,and its test and inspection methods were studied.Studies have shown that,compared with continuous gradation,the overall mechanical properties of UPC using discontinuous gradation design were better.The lime ratio of UPC should be controlled between 3.5-9.0%.Rutting test shows that the high temperature stability of UPC was significantly better than that of asphalt mixture.Low temperature bending test and bending tensile test show that bending resistance and bending tensile performance of UPC were weak.The freeze-thaw cycle test was more suitable for the research of UPC's resistance to water loss performance.Based on the comprehensive mechanical properties and cost of UP,it is recommended that the void ratio of UPC should be controlled at about 4.0%.Using the above UPC design method,UPC and LNBR modified UPC were prepared and their road performance was tested.The results show that UPC had higher Marshall stability,dynamic stability,and splitting strength than asphalt mixture.The immersion residual stability of UPC was greater than 100%,residual cleavage strength of UPC was greater than 80.UPC had excellent resistance to water loss under the effect of high temperature and water coupling,but the water stability performance was reduced under the effect of low temperature and water coupling.The flexural and tensile properties of UPC are between cement concrete and asphalt mixture.The flexural and tensile strength of UPC was greater than that of road cement concrete,and the bending strain was less than that of asphalt mixture.UPC had good resistance to oil erosion.Under the aging conditions,the mechanical properties of UPC tend to increase first and then decrease as the aging time increases.LNBR would cause the the Marshall stability,dynamic stability and splitting strength of UPC to be slightly reduced,but the Marshall flow value,bending strain and fatigue life of UPC were significantly improved.In order to observe the micro-characteristics of UP and UPC,the molecular dynamics was used to simulate UP and UPC.According to the UP molecular structure and curing characteristics,a molecular dynamics model suitable for UP curing was proposed.At the same time,this article used molecular dynamics to simulate the interface relationship between UP and aggregates,and obtained the interaction energy between UP and each aggregate component.The results showed that the interaction energy of the four main chemical components in aggregates from strong to weak was in the order of Al₂O₃,Fe₂O₃,Ca O,Si O₂.Aiming at the curing behavior of UPC,by changing the types of UP,initiators,tougheners,and aggregates,the Kissinger equation and Crane equation were used to study the effects of UPC components on the curing process of UP.The results showed that the apparent activation energy of bisphenol A-type UP was higher than that of m-benzene UP.The effect of MEKP on the apparent activation energy of UP was greater than that of BPO.LNBR improved the curing kinetic characteristic temperature and apparent activation energy of UP.The influence of aggregates components on the curing kinetic behavior of UP from strong to weak was in the order of Al₂O₃,Fe₂O₃,Si O₂,Ca O.