Research On Polymer Modified Material Smixing Radio Forrapid-Repairing Of Thin Layer Cement Concrete Pavement

The surface destruction of cement concrete pavement takes place frequently, destruction of structure will occur unless been repaired timely,affecting the service life of pavement.In addition to strengthening pavement routine main tenance, research onrapid-repairing materials is necessary.At first,analyze and calculate the stress on the pavement under the standard axle load in this article,getting the mechanical properties of repaired pavement.Then, according to the requirements of thin cement concrete pavement repaired quickly,using silica fume and polymer powder modify property of cementing materials. After a series of proportion testing, the fluidity, strength, flexibility, adhesion, shrinkage and other properties of sulfur aluminate cement mortars meet the actual requirements of the project.Through the test of pavement repairing project, pavement performancehas achieved relatively satisfactory results. The main contents and conclusions are as follows:(1)Analyzing the maximum shear stress variation of pavement structure, the results show that the maximum shear stress declines with the increasing of repairing surface structure thickness. Getting the maximum shear stress under normal status, it can provide guidance for material ratio as an interface structural strength standard. And the horizontal load is too large to slippage damage of structure, for the shear stress exceeding the shear strength of the surface layer.(2)Researching on the composition of a thin layer of rapid repairing materials,related work performance and mechanical testing have finished.Rapid hard ening sulfur aluminate cement,polymer and silica fume compound bya certain proportion,which are able to play an important role in micro filler effect and ball effect. Improving the fluidity and setting time of repairing materials to meet the requirements of the construction site, repairing materials have characteristics of fast hardening and early strength, late strength increasing steadily.Compressive and flexural strength of the surface layer structurein fourhours satisfy design standards of cement concrete pavement under heavy grade of traffic load,with traffic open quickly.(3)Experiments about binding strength test between repairing surface structure and cement concrete pavement have been finished, adhesive properties of composite structure improved by taking measures of smearing interface agent, roughening structure surfaceand others.Testing the shrinkage performance of repairing materials, the early shrinkage is lower than ordinary cement mortar, whilethe two dataare closer gradually with the extension of test time. Lower shrinkage make surface structur estabilized, reducing the surface micro-fractures of pavement structure effectively.(4)The repairing material ratio of laboratory is used as a reference,carrying out repairing work of thin layer cement concrete pavement.Makerelated repairing program combined with practical engineering, summary corresponding construction processes,and then analyze and solve practical problems about practical applications one by one. Practical experience has shown that the repairing surface layer and the old concrete pavement improved adhesive properties, which is able to with stand the combined effect of vehicle load and temperature stress.While traffic closed timeis reduced, the repaired pavementis in good condition overall three months later after the opening.It doesn’t appear that the case of a large area pavement crushed or flake, the desired objectives achieved.