(1) Take the gravel actually used in the construction site, calculate according to the particle composition, and determine the composition ratio of all kinds of gravel (16 ~ 3 1.5) mm gravel is 23%, (10 ~ 20) mm gravel is 29%, (5 ~/)

(2) Cement dosage

The cement content is expressed as the percentage of cement quality in the dry mass of all coarse and fine aggregates, that is, cement content = cement quality/dry aggregate quality, and the cement content of this cement stabilized subbase is 3%.

(3) Mix the mixture according to the selected cement dosage, and conduct vibration compaction test. The optimum water content of the mixture is 3.6%, and the maximum dry (compacted) density is 2.435g/cm3.

(4) According to the optimum water content and the calculated dry density, prepare the test piece (using vibration molding method). The samples were kept wet for 6 days under standard curing conditions, and then soaked for 24 hours. The unconfined compressive strength test is carried out according to the current Test Code for Stabilized Materials of Inorganic Binders in Highway Engineering.

(5) The actually used cement dosage and water content should be slightly increased compared with the indoor test, with the cement dosage slightly increased by 0.2%~0.5% and the water content slightly increased by 0.5% ~ 1.0%.

Extended data:

After the mixture ratio test of cement stabilized macadam subbase is completed, the influence of the delay time of cement stabilized macadam (the interval time from mixing with water to specimen molding) on the performance of cement stabilized macadam should also be tested.

After mixing the mixture with the proposed cement dosage, the test pieces were made with a delay of 65438 0 hours, 2 hours, 3 hours, 4 hours, 5 hours and 6 hours respectively. After curing to the specified age under standard curing conditions, the unconfined compressive strength test is carried out, and the relationship curve between delay time and strength is drawn according to the test results.

According to the relationship curve between delay time and strength and the required strength, the allowable delay time in the construction process is determined.

References:

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