Experimental Research On Composite Pavement Using Geotextiles To Reduce Reflection Cracking Caused By Loads

Reflection cracking is one of the major distresses on rigid-flexible compositepavement. Researches of preventing reflection cracking have deepened but still need toimprove. Depend on the ERGUANG highway construction project, this paper proposesto pave geotextile stress-absorbing layer as anti-reflection cracking measures, andexecute the related experimental research.The research start with introducing the fracture mechanics theory and utilizingfinite element analysis software modeling to investigate the causes and expandingmechanism of reflection cracking. Then emphasize to contrastively test theanti-reflection cracking efficiency of all kinds of geotextiles base on the theoreticalanalysis. The mechanical properties contrast tests of the three types of geotextiles showsthat these materials all possess strong anti-aging abilities so that they can keep a relativehigh mechanical level compare with before aging, and also satisfy the requirement forlong-term effectiveness of anti-crack on composite pavement. The performance ofresisting bending-tensile stress and shearing stress of geotextiles are studied by MTSfatigue loading test as well as the influence of interface exposing aggregate onanti-shearing reflection cracking. The number of fatigue loading repeats and the averagerate of reflection cracking development whose expression is originally defined are usedto evaluate the goetextiles’ performance on efficiency of anti-reflection cracking indifferent stages of development of reflection cracking as a significant indicator. And theorders of quality and efficiency of these materials are given. The MTS test resultsindicate that the geotextiles significantly contribute to composite pavement fatigue lifesaving under the states both of indirect bending-tensile and indirect shearing, especiallythe materials that composite of fiberglass and polyester warp knitting paving mat andimport fiberglass-polyester paving mat exhibit much higher performances on the twoaspects that prevent reflection cracking appearing and slow the pace of crack expanding.The test results also shows that the procedure of interface exposing aggregateadvantageously influences the performance of resisting shearing reflection cracking. Asan additional research and verification test, rolling-load fatigue test confirms the resultsof MTS fatigue loading test so well that it enhances the reliability of the conclusions ofthe research.Finally, after the technical and economic analysis, which is based on the prediction of composite pavement fatigue life, in connection with the cost of materials ofgeotextile stress-absorbing layer and their construction process characteristics, the paperprovides technical suggestions of material selection and construction of anti-reflectioncracking layer to ERGUANG highway project.