Standard compaction test is an indispensable and important test item to control the compaction quality of lime soil, and an important prerequisite for reliable compaction is to require the maximum dry density to accurately correspond to the actual dry density of the measuring point. The standard density is a scale used to measure the degree of compaction on site, and the quality of subgrade can be measured by the standard density. Therefore, when we do the compaction test to determine the standard density, we must do it in strict accordance with the test regulations and related requirements to ensure that the standard density has sufficient accuracy and achieve the purpose of guiding and controlling the engineering quality.
In addition, in the process of construction, we should always pay attention to whether the soil quality of the fill has changed. Once the change is found, the compaction test should be redone in time to be objective and fair and ensure the engineering quality.
Attach importance to the construction of lime-soil test section
Before the formal construction of lime soil, the construction of the test section must be carried out, which is an essential and important working procedure before the construction of lime soil. Through the construction of the test section, we can determine the selection and optimal combination of compaction machinery, the basic principle of rolling, the mixing times required for lime-soil uniformity, the loose paving coefficient and the thickness of compaction layer, and the allowable range of water content before rolling deviates from the optimal water content. The determination of these parameters provides valuable first-hand reference data for large-scale lime-soil construction in the future and lays a solid foundation for high-quality and efficient construction in the future.
Control moisture content before grinding.
Water content is a particularly sensitive index for the compaction of lime soil, which has a significant impact on the compaction effect, so the quality of water content control will directly affect the success or failure of compaction. At the same time, for the construction unit, from the economic point of view, rolling is the best way when it is close to the optimal water content. The specification requires that the water content is within 65438 0% of the optimum water content, and the rolling effect is the best, but this range is not static, depending on the specific conditions of the environment such as weather, temperature and season during construction. It is very important to measure the moisture content of lime soil in time and accurately before rolling, so as to control it in a state close to the optimal moisture content.
The ash should be evenly distributed.
When road mixing method is used for lime soil construction, many construction units do not pay enough attention to the uniformity of ash sprinkling, and workers are very random when sprinkling ash, which leads to great deviation of ash dosage, some of which are rare. However, the influence of ash dosage on compaction degree is obvious, which will lead to the high compaction degree even exceeding 100 in places with less ash distribution, and the "illusion" of insufficient compaction degree will appear in places with more ash distribution. This problem is easy to be ignored and should be paid enough attention to.
For "secondary dusting", it is necessary to consider whether it is necessary to carry out standard compaction again.
The situation of "secondary lime sprinkling" is mainly due to the fact that the lime has been sprinkled completely or the lime soil has not been leveled and rolled before mixing, and the construction can not be organized for many days, resulting in more loss of available calcium in lime, lower quality grade of lime and lower technical standards. In order to ensure the strength of lime soil can meet the requirements, lime has to be added again, but with the increase of lime dosage, the actual dry density of the construction layer becomes relatively small. At this time, if the original standard density is used again, it may cause the "illusion" of insufficient compaction.