The Design And Study On Cement Fly-ash Stabilized Hoggin

The cement stabilized aggregate and the lime fly ash stabilized aggregate are two typical semi-rigid base course materials. The poor crack resistance of cement stabilized aggregate and low early strength or complex construction of the lime fly-ash stabilized aggregate are key problems affecting the quality of road construction in our country. Replacing some lime with cement in the lime fly ash stabilized aggregate is a effective method to increase the material's early strength. Because of the lime being, the complex technologies such as the lime's transportation, loading and dolomiting also can not be avoided and it will pollute the environment. It has reported that the lime might reject the hydration of cement and reduce the material's strength. So, the replacing all lime with cement has been carried out, which is called cement fly-ash stabilized hoggin. Recently, little research about this material has been carried out and some experimental sections have been constructed. But the studying, especially about the technical requirement, the method to design the proportion and elements affecting material's performance, is not perfect and sufficient, which is confining the generalization and application of this material.This manuscript studies elements such as content and quality of fly-ash, the cement content and aggregate's gradation influencing the material's strength. Conclusions indicate that there is a strength peak when the fly-ash content is 10%.And activity of fly-ash has correlation with the strength of cement fly-ash stabilized hoggin. To attain the same strength grade, the content of cement in cement fly-ash stabilized hoggin has reduced by 0.5¹% comparing with cement stabilized hoggin. This material has a capability of adapting with different aggregate's gradation and the 4.75mm passing rate can reduce to 30%. Through the studying about the mechanical property of cement fly-ash stabilized hoggin, this manuscript discover that the material has good strength growing performance that its 90d strength growing rate is 385% and its splitting strength that the 7d splitting strength is 0.347MPa and the 90d splitting strength is 0.700MPa accord with requirement in the norm. But compared with cement stabilized hoggin, its modulus of resilience has reduced by 16%, which is good at improving the material's crack resistance.This manuscript studies the volumetric design method and ensures the compacting density is the best designing parameter. Than, this manuscript designs the proportion of cement fly-ash stabilized hoggin and examine its feasibility. The conclusions report that the volumetric design method can be used in designing of proportion of semi-rigid base course materials including cement fly-ash stabilized hoggin.In addition, this manuscript studies different influence that cements with different SO₃ content give sand-cement grout, cement-fly ash binder, cement fly-ash stabilized hoggin and probe the action that SO₃ appears in different material system. The conclusion discovers that the contentof SO3 in cement can attain 5% in cement fly-ash stabilized hoggin and explains the mechanics using the theory of improving the gelatinization and aperture structure.Through LCA analysis of three road base materials and application, the performance of environment protection, technologies, applying results and economic effects have been researched. Conclusion shows that the is a environmental road base material with good performance, obviously economic effects and convenience of generalization.