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.

結合改建工程，采用現場冷再生處理舊路面面層及基層，取得良好效果。冷再生基層是指把原路面的舊面層、基層用專用路面再生機，按照一定的厚度進行破碎處理，同時加入一定規格和數量的新集料、粘合劑（水泥等），按一定配合比拌和，之后進行整形、碾壓，使其恢復達到路面基層或底基層技術要求的施工工藝。現場冷再生技術，不僅可以節約能源，降低施工成本，更有益于環境保護。

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、再生老路概況

1. Overview of the old road of regeneration

改建工程全長29.374km，其中k0+000-k8+850段進行冷再生施工，寬7m。原路面面層為3cm瀝青碎石，基層為15cm石灰穩定土，冷再生處理舊路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、舊路面冷再生施工質量控制2.1試驗室確定冷再生施工技術指標

2. Quality control of cold recycling construction of old pavement

鑒于目前冷再生試驗無規定，本次試驗參照《公路土工試驗規程》（JTJ051-93）和《公路工程無機結合料穩定材料試驗規程》（JTJ057-94）進行。

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）改建工程冷再生技術為舊路面面層、基層再生為基層，設計強度1.5MPa。通過對現有材料進行分析，采用摻加粘合劑（水泥）的方法，保證基層強度。

(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）選擇水泥的摻配比例為百分之3、百分之4、百分之5、百分之6。通過擊實試驗、無側限抗壓強度試驗確定水泥的摻入量，試驗結果見表1。擊實、無側限抗壓強度試驗結果表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）經試驗室確定冷再生摻加水泥用量百分之5，施工過程中按百分之6控制，進行200m試驗路段施工，其壓實度、強度等各項指標均達到設計要求。

(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.