Study On The Strength Controlling Standard For Lime-fly Ash Stabilized Aggregates

As one of the most common semi-rigid base, Lime-fly ash stabilized aggregates has been widely used for its good intensity, therigidity and integrity, good water stability , good anti-frozen and also can turn wastes into useful.Bottom tensile stress as the standard is stipulated in Specifications for Design of Highway Asphalt Pavement (JTG D50-2006) and Compressive strength is used as the standard in material composition design and engineering quality, which created the unconformity between the standards in design and the standards in construction. Therefore, Based on theoretical research and systematically laboratory tests of Lime-fly ash stabilized gravel,proposed its proper strength controlling standard and specification.Firstly, the strength formation mechanism of Lime-fly ash stabilized aggregates was analyzed by theoretical research. The main factors which influence the strength of the materials was identified..The mechanical properties of the Lime-fly ash stabilized aggregates was studied and the variation rules of the material's strength was expressed. Finding the association between the splitting strength and compressive strength by large amounts of laboratory tests.Secondly, by studying the two common destruction forms of the Lime-fly ash stabilized aggregates supposed that the reasons caused the destruction was weakness of bottom tensile stress; The strength specification of the Lime-fly ash stabilized gravel has been researched and the reasonablity of splitting strength's becoming new strength controlling standard was desmonstratedThen, by collecting the datas of some typical structures and calculating the bottom tensile stress , the stress ratio of different road's was put forward.Finally, the splitting strength standard of 180d for lime-fly ash stabilized gravel was decided by calculation of the bottom tensile stress.Then according to the relation between 7 d's splitting strength and 180d's, the final standard of splitting strength was put forward and be tested by laboratory tests and Unconfined Compressive Strength standards in the Design Specification of Asphalt Pavement.Splitting strength standards for lime-fly ash stabilized aggregates was put forward for the first time in the thesis. The research will be useful for the design and construction of such pavements, and will have a significant influence on the improvement of lime-fly ash stabilized aggregates durability.