Design method for cement-stabilized broken gravel base or subbase integrated with structure

Abstract

The invention discloses a design method for a cement-stabilized broken gravel base or sub-base integrated with a structure, comprising the following steps: firstly drawing up a combination of pavement structures; establishing a calculation model, and determining the age and modulus of each structural layer in the model; calculating The tensile stress at the bottom of the cement-stabilized broken gravel base or sub-base; determine the 7d compressive strength design standard [Rc7] and the 7d splitting strength design standard [Rs7]; design the mineral material gradation; determine the maximum cement-stabilized broken gravel mixture Dry density ρmax and optimal water content wo; test 7d unconfined compressive strength Rc7 and 7d splitting strength Rs7, determine the amount of cement that satisfies Rc7≧[Rc7], Rs7≧[Rs7], and complete the design. The method has the advantages of low input cost, simple operation and good effect, and can effectively solve the problems that the existing cement-stabilized crushed gravel design is out of touch with the pavement structure and prone to shrinkage and cracking.

Description

technical field [0001] The invention relates to the field of traffic civil engineering, in particular to a design method for a cement-stabilized crushed gravel base or sub-base integrated with a structure. Background technique [0002] Crushed gravel or gravel is the main material for building road pavement bases. Compared with crushed gravel, broken gravel has fewer broken surfaces, smooth surfaces, and poor angularity, resulting in relatively low strength of cement-stabilized broken gravel and easy segregation. In order to increase the strength of cement to stabilize broken gravel and reduce segregation, increasing the cement dosage and adopting finer gradation have become the most common technical means in engineering practice. It is almost a consensus that the cement dosage should reach more than 4-6%. However, the consequence is that the cement-stabilized broken gravel base or the sub-base has serious shrinkage cracks, and other damages such as pumping and network crack...

AI Technical Summary

Problems solved by technology

Due to the low strength of cement-stabilized crushed gravel, it is almost the only means to ensure that the cement-stabilized crushed gravel meets the above-mentioned strength standards by increasing the dosage of cement. Increasing the amount of cement will cause serious shrinkage of the base or subbase of cement-stabilized crushed gravel Cracking will affect the service life of the pavement; (2) In the traditional design method, the splitting strength, modulus and tensile strength structure coefficient of cement stabilized macadam are pavement structural design parameters, while the only index for mixture design is 7d without side Therefore, the material performance requirements of the pavement structure cannot be considered in the design of the mixture, and the structure and material design are out of touch, so that the designed mixture cannot effectively control cracking

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