1. The subgrade should be filled with lime soil for the inspection of the basement. Before lime-soil construction, self-inspection shall be conducted at the grass-roots level, and the next lime-soil construction can be carried out only after passing the inspection. Excavate the steps at the junction of old and new roads as required. The steps are 0.8m high and 1m wide. The steps are excavated from bottom to top, and the excavation elevation is synchronized with the fill elevation.
2. Control of paving edge: In order to ensure the compactness of subgrade edge, the edge should be 30cm wider than each side of the design line. Sprinkling lime: after sprinkling, manually cooperate with machinery to determine the water content of lime; Whether the water content of lime soil meets the requirements of construction specifications is estimated by the water content of plain soil and lime. If you are not satisfied, sprinkle water to dry.
3. Lime-soil mixing: mix twice with a pavement mixer, and the mixing depth is 2cm greater than the loose paving thickness to ensure a better connection between the upper and lower floors. Manual inspection should be carried out during mixing to ensure the mixing depth. After mixing, the ash dosage shall be detected, and leveling and rolling shall be carried out after passing the inspection by the supervision engineer. If it is unqualified, add ash until it is qualified.
4. Leveling: Leveling with a grader immediately after mixing, and the horizontal slope of the top surface of the filling layer is not less than 2% at ordinary times. Lime soil will lose some water in the process of waiting, paving and leveling, especially in autumn and high temperature season. It is not easy to compact when rolling, and even fine cracks appear, indicating low water content. At this time, spray water with sprayers and sprinklers to facilitate compaction. In the process of construction, the water content of the filler should be detected regularly, and the corresponding watering drying should be carried out to ensure the compaction quality.
5, rolling, paving leveling, loose laying thickness, flatness meets the requirements, namely rolling. In this test section, vibratory roller is used for rolling, and the rolling sequence is from edge to middle, followed by static pressure, weak earthquake and strong earthquake, and the rolling times and rolling speed are recorded.
When rolling, the longitudinal rolling shall be carried out in the positive and negative directions, with each row of wheel tracks overlapping by 0.2-0.3m, the joint of the same layer horizontally overlapping by 0.4-0.5m, the longitudinal overlapping of two adjacent sections not less than 2.0m, and the staggered joints of the upper and lower layers not less than 3.0m, so as to ensure no pressure leakage and dead angle and ensure the uniformity of rolling.
6. Compaction degree detection: After compaction is completed, the compaction degree is detected, and the detection frequency is 4 points per 200m compacted layer. If the degree of compaction is not reached, it should continue to be compacted by strong vibration, and then continue to test until the degree of compaction meets the specification requirements, and then use static pressure for the next step of construction.
7, maintenance, testing qualified subgrade should immediately to preserve one's health for the soil, such as long-term exposure should be water curing, curing period of not less than 7d, it is forbidden to close the road during curing. Generally, before road construction, it is necessary to test the base, spread and level the base after passing the test, and then roll, compact and maintain it. After all the steps and processes are completed, the traffic can officially start.