Application Of Slab Grouting Technique For Composite Pavement

The research object of this paper is the treatment of cavity beneath road slab on the composite pavement of Guangzhou Northring expressway. It preliminarily discusses and practices the materials, mix proportion, construction technology and related evaluation methods of slab grouting on the composite pavement.Firstly, the author briefly introduces the present research status of cavity beneath road slab and slab grouting technique at home and abroad. Secondly, discusses the common identification methods of cavity beneath road slab,. puts forward the detection mean and method of cavity beneath slab suitable for the composite pavement through comparing and analyzing. Thirdly, By analyzing the grouting theory, it summarizes the key factors influencing the grouting effect are: pressure, hole distance, fluidity, grain size. Contrasts and tests the grouting material and mix proportion according to the slab grouting requirements of composite pavement. Then puts forward the fluidity requirement of material, besides the strength, expansion rate, bleeding other indexes, and finds the material and mix proportion suitable for slab grouting. After the test road, summarizes the slab grouting technique for composite pavement, determines the grouting pressure, hole arrangement, hole spacing and other key indexes. Finally, this paper tests the grouting effect through a variety of methods, and verifies that the above grouting technique, material and mix proportion can meet the requirements for slab cavity treatment of composite pavement.