1. Old road survey

冷再生技术适用于大部分沥青混凝土旧路大修与改建工程。需要对旧路进行详细的调查，主要包括以下内容:

Cold recycling technology is applicable to most asphalt concrete old road overhaul and reconstruction projects. First, a detailed survey of the old road is required, mainly including the following contents:

（1）对旧路结构和历年修补改造情况进行调查，了解路面病害情况，包括变形、裂缝、边缘破坏等。

(1) Investigate the old road structure and the repair and reconstruction over the years to understand the pavement diseases, including deformation, cracks, edge damage, etc.

（2）对旧路进行弯沉检测，以分析旧路的破坏状况和承载能力，确定重复利用旧路基层进行冷再生的必要性。

(2) The deflection of the old road is detected to analyze the damage status and bearing capacity of the old road, and determine the necessity of reusing the old road base for cold regeneration.

（3）对旧路结构层进行钻芯取样，以确定旧路结构层的厚度及各层材料的工程特性。

(3) Core drilling and sampling shall be carried out for the old road structure layer to determine the thickness of the old road structure layer and the engineering characteristics of the materials of each layer.

2、材料组成设计

2. Material composition design

通过试验分析，我们认为冷再生层的性能与混合料级配有着显著而密切的关系。如若旧料中4.75mm以上的粒料含量过低(<40%)，则需加入部分级配的新骨料；若旧料中4.75mm>80%)，则会导致细料(特别是<0.6mm的集料)对空隙的填充不足，混合料强度偏低，则需在冷再生混合料中加入部分级配的细集料，以便形成具有良好级配的骨架密实结构，提高混合料的强度。但这无疑都会提高冷再生结构层的造价，需与新建的结构层进行经济比较以后再实施。

Through experimental analysis, we believe that the performance of cold recycled layer is significantly and closely related to the mixture gradation. If the content of aggregate above 4.75mm in the old material is too low (< 40%), some graded new aggregate shall be added; If 4.75mm > 80%) in the old material will lead to insufficient filling of voids by fine materials (especially aggregates < 0.6mm) and low mixture strength, it is necessary to add partially graded fine aggregates to the cold recycled mixture, so as to form a skeleton dense structure with good gradation and improve the strength of the mixture. However, this will undoubtedly increase the cost of cold regeneration structural layer, which needs to be implemented after economic comparison with the new structural layer.

3、沥青混凝土路面现场冷再生技术的施工工艺

3. Construction technology of on-site cold recycling technology for asphalt concrete pavement

冷再生技术的施工工艺按加水在撒布外掺剂的前后顺序分为先加水施工和后加水施工两种。经过对试验段铺筑效果分析后发现，先加水施工的冷再生结构层更容易压实成型，且表面均匀、平整、光滑，压实度容易满足要求。建议在水源充足，时间允许条件下采用先加水施工工艺。

The construction process of cold regeneration technology is divided into two types: water adding construction first and water adding construction later according to the sequence of water adding before and after the distribution of admixture. After analyzing the paving effect of the test section, it is found that the cold recycled structural layer constructed with water first is easier to compact and form, and the surface is uniform, flat and smooth, and the degree of compaction is easy to meet the requirements. It is suggested to adopt the construction process of adding water first when the water source is sufficient and time permits.

（1）沥青混凝土路面现场冷再生施工前的准备工作

(1) Preparation before cold recycling construction of asphalt concrete pavement on site

（2）沥青混凝土路面现场冷再生施工工艺

(2) On site cold recycling construction technology of Asphalt Concrete Pavement

冷再生技术可以充分利用旧路资源，对旧路面层及基层进行再生利用形成新的路面基层。是对旧路推除重建的完全否定，既要挖除旧路重做结构层，又要把旧路废料运走堆放。二者相比，前者直接和简洁，经济效益显著。在路面结构设计理念上，废旧沥青的再生利用将会改变过去以刚性材料做基层的设计观点。是沥青路面再生利用养护技术的一次革命。

Cold recycling technology can make full use of the old road resources and recycle the old pavement layer and base to form a new pavement base. It is a complete negation of the demolition and reconstruction of the old road. It is necessary to dig out the old road and rebuild the structural layer, and also transport the waste of the old road away and stack. Compared with the two, the former is direct and concise, with significant economic benefits. In the design concept of pavement structure, the recycling of waste asphalt will change the design view of using rigid materials as base course in the past. It is a revolution of asphalt pavement recycling and maintenance technology.