| Air pollution has a major impact on human life,work and ecosystems,endangers human health,and causes global climate change.Atmospheric particulate matter is the main air pollutant,and road dust caused by vehicle emissions and urban construction is an important source of urban air pollution.Many cities reduce road dust by increasing the number of sprinkler vehicles and working frequency.However,the pollution sources of road dust are complex and uncertain due to human interference,which is easy to cause secondary pollution.It is difficult to effectively suppress only by sprinkling water.Since dust suppressants can use functional groups such as carboxyl and hydroxyl groups combined with organic substances to improve moisturizing performance,and can be combined with road dust after drying to achieve longterm dust suppression,some areas also use spraying dust suppressants to reduce road dust.At present,most of the composite dust suppressants with good application effect in the market are developed for coal or mineral powder.Due to different applicable environmental conditions and functional requirements,most of them cannot be directly applied to roads.At the same time,the urban road environment is complex and there are many people and vehicles passing through it.The slippery road surface caused by spraying dust suppressants is easy to cause traffic accidents and casualties,however,the road dust suppressants that have been developed at present have not considered this problem in a targeted manner.Therefore,in this study,on the basis of the selected dust suppressant formula with good performance,the anti-skid performance was improved in a targeted manner,and the anti-skid performance evaluation,physical and chemical indexes and performance indexes,small-scale test were carried out to explore the comprehensive performance and practical application effect of the improved dust suppressant.which will provide a certain theoretical basis for the development and application of road dust suppressant.At the same time,this study also set up a set of anti-skid performance test device of dust suppressant,which provided a certain technical support for screening a large number of dust suppressant materials with anti-skid performance quickly and effectively.The main findings of this study are as follows:(1)An anti-skid compound dust suppressant was prepared by improving the existing road dust suppressant formula.A road dust suppressant with good performance was identified through multiple screening.The original formula of road dust suppressant is 0.50%methyl cellulose,0.70%soluble starch,0.25%fatty alcohol polyoxyethylene ether and 0.10%polyvinyl alcohol,and then targeted improvement of its anti-skid performance through blending modification,and synergistic improvement of anti-freeze and dissolving performance to prepare an improved dust suppressant.Taking the anti-skid performance,viscosity value,antievaporation performance and dust suppression efficiency as the experimental indicators,the topsis analysis method shows that the optimal formula of the improved dust suppressant is 0.50%PVA-MC(Blend modified dust suppression material),0.15%water-soluble starch and 0.25%fatty alcohol polyvinylether.(2)The anti-skid performance evaluation,physical and chemical index characterization and performance index characterization of the improved formula are carried out.The characterization results are:pH value is 7.15;viscosity value is 121.25 mpa·s;freezing point is-10℃;evaporation at 20℃ is 0.475 kg/m2,which indicates that it has good anti-evaporation performance;the mass loss rate of dust samples after 3 rain showers is 23.65%,which indicates that it has good anti-rain erosion performance;The compressive strength of the air-dried film is good enough to support the passage of people and vehicles,and it is not easy to break;Under no wind,the dust suppression efficiency is 98.0%,the wind speed is increased to 5-6 level,the dust suppression efficiency is only reduced by 5.0%,which indicates that it has good wind erosion resistance.To sum up,the comprehensive test performance of the improved dust suppressant is good.(3)Through the small-scale experiment,it is observed that the practical application of the improved dust suppressant can meet the anti-skid requirements.It is found that the practical application effect of the improved dust suppressant was observed through a small test.After spraying,the improved dust suppressant can meet the anti-skid requirements in the application of asphalt roads and concrete roads.Compared with the existing dust suppressants on the market,the improved dust suppressant has higher applicability to climatic conditions because of its lower freezing point,and its anti-freezing and dissolving performance is good,and it is not easy to agglomerate in the production process,non-toxic and harmless and has good economic benefits.(4)A set of anti-skid performance testing equipment for dust suppressants was built.The device uses anti-slip distance instead of friction coefficient,which is simple to manufacture and low in testing cost.It can also simulate the field environment,and has a good advantage in quickly screening anti-slip dust suppression materials. |
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