Effect Of Flexible Fiber On Pavement Performance Of Concrete Mixed With Fly Ash

Shale ceramsite lightweight aggregate concrete is a new type of lightweight concrete,and the flexible fiber as reinforced material can improve the concrete performance from various aspects.This paper focus on the influence of road performance when the flexible fiber is mixed to shale ceramsite lightweight aggregate concrete,on the basis of literature review and theoretical analysis.Firstly,this article has studies on the workability of the new mix of shale ceramsite concrete,and finds that PP fiber and PVA fiber have no adverse effect on the performance of lightweight aggregate concrete in certain dosage range.What's more,the dispersion performance of flexible fiber is improved through the adoption of new type fiber dispersion technology.By adopting the orthogonal experiment,the impact on compressive strength,bending and resistant performance of ceramsite concrete is studied under the different content and different lengths of PP fiber and PVA fiber hybrid fiber.Results show the strength of ceramsite concrete containing the mixed fiber will be improved in a certain degree.The type and dosage of fiber have a greater influence on the mechanical properties of lightweight aggregate concrete,while the influence of fiber's length is smaller.On the basis of the above research,the mixture ratio of flexible fiber is optimized,and the further tests on impermeability,fracture toughness and fracture energy of concrete will be done.The study finds that the optimized matching will significantly improves the above performance of concrete,and PVA fiber's effect on enhancement is better than PP fiber's.Through reading and analyzing,author find that when the fiber can be evenly dispersed in concrete,the higher the fiber content,the better the crack resistance,and under the action of load force,the higher energy consumption,the higher the fracture toughness of the ceramsite concrete,the higher the fracture energy.This paper observes and analyzes the microstructure of flexible fiber ceramsite concrete by using electron microscope,and explains the enhancement mechanism of fiber from the aspects of microstructure and macro phenomenon.The study shows that the mixed fiber provides a 3 d space truss structure for ceramsite concrete,and makes cement and shale ceramsite being better together,so as to improve the compactness and uniformity of concrete and reduce its native defects.At the same time,the flexible fiber can reduce and limit the production and development of the cracks of concrete in the unloading process,and thus improve the performance of the ceramsite concrete.