Action principle of cement stabilized macadam: Cement stabilized macadam takes graded macadam as aggregate, fills the gap of aggregate with a certain amount of cementing material and sufficient mortar volume, and spreads and compacts according to the principle of embedding and squeezing.
Its compactness is close to its compactness, and its strength mainly depends on the interlocking principle between crushed stones. At the same time, there is enough mortar volume to fill the gap of aggregate. Its initial strength is high, and the strength increases with age, and soon forms a plate shape, so it has higher strength, better impermeability and frost resistance.
The cement content of cement stabilized macadam is generally 3% ~ 6% of the mixture, and the 7-day unconfined compressive strength can reach 5.0Mpa, which is higher than other subgrade materials. After surviving, cement stabilized macadam is not muddy in the rain and has a solid surface, so it is an ideal base material for advanced pavement. ?
Cement stabilized macadam belongs to medium-grained soil. Because water stability contains cementing materials such as cement, it is required that the whole construction process should be completed before the final setting of cement, and the quality standard should be reached at one time, otherwise it will be difficult to repair. Therefore, it is required to strengthen the construction organization design and plan management, increase the sense of urgency and responsibility of on-site construction personnel, speed up the construction progress, increase the degree of mechanized construction and improve the mechanical efficiency.
Extended data:
Before laying cement stabilized macadam, the subbase should be cleaned and sprayed with proper amount of water to keep it moist.
Mixing adopts factory centralized mixing. Before using the plant mixing equipment, the plant mixing equipment and various metering systems should be debugged to make the water content, aggregate gradation and cement content of the mixed mixture meet the matching requirements, so that the machine can operate normally and the output of the mixer is consistent with the paving production capacity used.
When paving and rolling, the paving coefficient is between 3 and 5. The principle of "rather high than low, rather scraping than mending" must be implemented in the construction, and all construction projects should be completed before the final setting of cement. After rolling, the compactness test shall be conducted immediately. If the test result is not up to standard, roll again.
In general, cement stabilized macadam can not be constructed until 24 hours after the operation is completed. The interval between it and the kerb should not be too long, otherwise, after the mixture forms the slab, the slab will become hard, which will increase the construction difficulty, and it is easy to destroy the integrity of the slab by knocking the slab.
The curing time shall not be less than 7 days. During this period, vehicles are prohibited from passing, and they are maintained with sprinklers 2~4 times a day to keep them moist.
References:
Baidu encyclopedia-cement stabilized macadam