Experimental Study On Mechanical Properties Of Salt Rock Base Of Chalkhan Dry Salt Lake Stabilized By Lime And Fly Ash

Based on the special geographic location,natural climate and road construction of the Chaerhan Dry Salt Lake area,this paper proposes the use of lime fly ash to strengthen salt rock materials as a semi-rigid base for pavement.Through a large number of laboratory tests,the basic mechanical properties and temperature shrinkage properties of lime-lime stabilized salt rock materials were tested and analyzed,and the following conclusions were mainly drawn:(1)In accordance with the relevant test procedures,the technical indicators and composition of each raw material of salt rock,saturated brine,lime and fly ash were tested.At the same time,the uniaxial compressive strength of the salt rock in the natural state was tested,and the typical mix ratio of the salt rock and lime-lime stabilized salt rock was tested by compaction to determine the optimal water content and maximum dry density.(2)Through the five-factor five-level regression orthogonal test design,27 groups of unconfined compressive strength tests were carried out on the limestone stabilized salt rock materials,and the test results were analyzed by regression to determine the secondary between the strength and each factor Regression equation,at the same time,analyzes the influence of various factors(brine content,lime content,fly ash content,initial dry density and curing age)on the strength of lime-lime stabilized salt rock materials and the interaction between various factors.The curing age is 7 days,and the optimal mix ratio of lime-lime stabilized salt rock material is found based on the maximum unconfined compressive strength(lime content 18%,fly ash content 25%,salt rock content is 57%,the brine content of the whole test piece is 6%,and the initial dry density is 1.798g/cm~3).(3)The basic mechanical properties of the two limestone stabilized salt rock materials and the pure salt rock group specimens were used as controls for indirect tensile testing at three ages(7d,14d,120d)Strength,bending strength,compressive rebound modulus test,study the indirect tensile strength,bending strength,compressive rebound modulus of each group of specimens with age,and comparative analysis of the best mix ratio The improvement of the mechanical properties of the lime-lime stabilized salt rock materials,and compare the mechanical properties with the conventional stable materials.The results show that the indirect tensile strength,flexural tensile strength,and compressive rebound modulus of the lime-lime stabilized salt rock material at the optimal mix ratio are greatly improved,and the mechanical properties are close to or higher than conventional Stable materials.(4)The temperature shrinkage mechanism of lime-lime stabilized salt rock materials is analyzed,and the temperature-shrinkage performance tests of the optimal mix ratio group of the lime-lime stabilized salt rock materials and pure salt rock groups are conducted to study the temperature shrinkage performance of each group of materials with age Change the law,and compare the temperature shrinkage performance with conventional ash stabilized materials.The results show that the temperature-shrinkage performance of the limestone stabilized limestone material under the optimal mix ratio is close to that of conventional limestone stabilized materials.The above-mentioned series of mechanical performance test studies on lime-lime stabilized salt rock materials show that in saturated brine environment,the use of lime and fly ash to reinforce salt rock materials can greatly improve the mechanical properties of stable materials,So that the road performance of limestone stabilized salt rock semi-rigid base is more.The recommended mix ratio for limestone fly ash stabilized salt rock base construction is lime:fly ash:salt rock=18:25:57.