Study On Preparation And Performance Of Fiberglass Tubes For Cured In Place Pipe(CIPP)

Drainage pipes are like the"blood vessels"of the city.The paralysis or disrepair of drainage pipes seriously affects the safety of people’s lives and properties and the healthy operation of the city.UV CIPP have become one of the mainstream trenchless repair technologies in China due to its advantages of short construction time,small operation area,and small traffic impact.Fiberglass tubes are the core material of UV CIPP,and its quality directly affects the construction quality.At present,there is still a lack of research on fiberglass lining tubes at home and abroad,including standardization.In response to this problem,this paper studied the preparation and performance of fiberglass lining tubes,systematically analyzed the causes of bubble defects in tubes,and conducted products and engineering standardization practices.This paper studied the quality standard of fiberglass lining tubes.Through investigation and analysis of the status quo of domestic and foreign standards,combined with domestic application and research progress,formulated key parameters to control the quality of the lining tubes.Comprehensive existing product indicators to determine:the carrier of fiberglass lining tubes were composed of two or more layers of fiberglass fabrics,single layer thickness≥0.7 mm;according to its functional requirements,the UV transmittance of the inner film should≥50%,and the outer film should≤0.5%;the vacuum degree of the infiltration process should≥30 k Pa;the bending strength of liner should≥125 MPa,the flexural modulus should≥8000 MPa,and the tensile strength should≥80 MPa;the long-term performance is tested by 10000 h accelerated load,and the attenuation coefficient is not less than 2.In view of the preparation process of fiberglass lining tubes,the influence of resin system viscosity,infiltration vacuum degree,infiltration environment temperature,irradiation intensity,irradiation time and other process parameters on the final performance was studied.The result showed:Adding an appropriate proportion of thickener to the resin can effectively control the viscosity and thickening speed of the resin system;Increasing the infiltration vacuum degree and ambient temperature was beneficial to the resin infiltration and the improvement of material properties.The intensity of UV light irradiation decreased with the increase of material thickness and irradiation distance.When the irradiation dose was 3148.1 m J/cm~2,the mechanical properties of the material under the experimental conditions reached the highest,and the flexural modulus was 11614.75 MPa.In this paper,the microscopic characteristics of the bubbles in the lining material were observed by microscopy and SEM.By analyzing the mechanism of bubble formation in the liners,the effect of bubble defects on the mechanical properties of liners was explored.The result showed:when the degree of vacuum applied during infiltration was low,the enclosed bubbles were larger,the shape was irregular,and the porosity of the curing tube is larger;when the vacuum degree was large,the bubble size was small,the shape was spherical,and the porosity of the curing tube was small;when the temperature of the soaking environment was low,the bubbles were flat and oval,the size was large,and they were mostly retained between the resin-rich fabric layers;When the temperature was high,the bubbles were elliptical,but the length and width were relatively small,the overall size was small,and they were mostly retained between fiber bundles or fiber filaments.As the porosity of the liner increased,the strength and modulus of the composite showed a decreasing trend.In this experiment,when the infiltration environment temperature was 40℃and the vacuum degree was 0.08 MPa,the porosity was 5.378%,the mechanical properties were the highest,the elastic modulus was 13612.88MPa,the bending strength was 342.09MPa,and the tensile strength was 202.33MPa.This paper took the major defect repair project of the municipal drainage pipe network in the urban area of Chengdu as an example,combined the basic data and application experience in the construction process,summarized the design,materials,equipment,construction process,acceptance and other matters of UV CIPP.In order to standardize the construction process and provide support for the technical regulations of UV curing construction.