In recent years, China's highway development is very rapid. With the increasing traffic volume, a large number of highways are close to the design service life, and need to be overhauled or reconstructed. The on-site cold recycling technology is the appropriate way of maintenance or reconstruction. On site cold recycling technology can not only save energy, reduce construction cost, but also benefit environmental protection.

结合改建工程，采用现场冷再生处理旧路面面层及基层，取得良好效果。冷再生基层是指把原路面的旧面层、基层用专用路面再生机，按照一定的厚度进行破碎处理，同时加入一定规格和数量的新集料、粘合剂（水泥等），按一定配合比拌和，之后进行整形、碾压，使其恢复达到路面基层或底基层技术要求的施工工艺。现场冷再生技术，不仅可以节约能源，降低施工成本，更有益于环境保护。

Combined with the reconstruction project, the on-site cold recycling is used to treat the old pavement surface and base, and good results are achieved. Cold recycling base is a construction technology that uses a special road recycling machine to crush the old surface and base of the original road according to a certain thickness, and at the same time adds a certain specification and quantity of new aggregate and binder (cement, etc.), mixes according to a certain mix proportion, and then carries out shaping and rolling, so as to restore it to meet the technical requirements of the road base or subbase. On site cold recycling technology can not only save energy, reduce construction cost, but also benefit environmental protection.

1、再生老路概况

1. Overview of the old road of regeneration

改建工程全长29.374km，其中k0+000-k8+850段进行冷再生施工，宽7m。原路面面层为3cm沥青碎石，基层为15cm石灰稳定土，冷再生处理旧路18cm。

The total length of the reconstruction project is 29.374km, in which the cold recycling construction is carried out in K0 + 000-k8 + 850 section, with a width of 7m. The surface course of the original pavement is 3cm asphalt macadam, the base course is 15cm lime stabilized soil, and the cold recycling treatment of the old road is 18cm.

2、旧路面冷再生施工质量控制2.1试验室确定冷再生施工技术指标

2. Quality control of cold recycling construction of old pavement

鉴于目前冷再生试验无规定，本次试验参照《公路土工试验规程》（JTJ051-93）和《公路工程无机结合料稳定材料试验规程》（JTJ057-94）进行。

Since there is no national regulation for cold recycling test at present, the test is carried out according to "Specification for highway geotechnical test" (jtj051-93) and "Specification for test of inorganic binder stabilized materials in Highway Engineering" (JTJ057-94).

（1）改建工程冷再生技术为旧路面面层、基层再生为基层，设计强度1.5MPa。通过对现有材料进行分析，采用掺加粘合剂（水泥）的方法，保证基层强度。

(1) The cold recycling technology of the reconstruction project is that the old pavement surface layer and the base layer are recycled as the base layer, and the design strength is 1.5MPa. Through the analysis of the existing materials, the method of adding adhesive (cement) is adopted to ensure the base strength.

（2）选择水泥的掺配比例为百分之3、百分之4、百分之5、百分之6。通过击实试验、无侧限抗压强度试验确定水泥的掺入量，试验结果见表1。击实、无侧限抗压强度试验结果表1

(2) The proportion of cement is 3%, 4%, 5% and 6%. The cement content is determined by compaction test and unconfined compressive strength test. The test results are shown in Table 1. Table 1 test results of compaction and unconfined compressive strength

（3）经试验室确定冷再生掺加水泥用量百分之5，施工过程中按百分之6控制，进行200m试验路段施工，其压实度、强度等各项指标均达到设计要求。

(3) The laboratory determined that the dosage of cold recycling cement is 5%, and the construction process is controlled by 6%. The construction of 200m test section is carried out, and the compaction, strength and other indicators meet the design requirements.