Cold recycling machine is a kind of high efficiency, multi-purpose construction machinery. It is mainly used for milling of asphalt concrete pavement and regeneration of old asphalt pavement after adding asphalt, water and other materials. It can also be used for on-site mixing of stabilized soil at the base and bottom of highway, urban and rural road, airport, wharf, parking lot and other projects.

在对道路进行养护工作时，我们需要对原先的道路进行调查，以确保在冷再生机租赁后其进行道路养护工作的顺利进行。

In the road maintenance work, we need to investigate the original road to ensure the smooth progress of road maintenance work after the rental of cold recycling machine.

一、旧路调查

1、 Survey of old roads

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。先需要对旧路进行详细的调查，主要包括以下内容:

Cold recycling technology is suitable for most old asphalt concrete road repair and reconstruction projects. First, we need to conduct a detailed investigation on the old road, 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. To 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 condition and bearing capacity of the old road and determine the necessity of reusing the old road base for cold recycling.

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. In order to determine the thickness of the old road structure layer and the engineering characteristics of each layer material, core drilling sampling is carried out on the old road structure layer.

二、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，则需加入部分级配的新骨料;

Through the test analysis, we think that the performance of the cold recycling layer has a significant and close relationship with the mixture gradation. If the content of more than 4.75mm aggregate in the old material is too low, some graded new aggregate should be added;

若旧料中4.75mm以上的粒料含量过高，则会导致细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。

If the content of more than 4.75mm particles in the old material is too high, it will lead to insufficient filling of fine materials for voids and low strength of mixture, so it is necessary to add some graded fine aggregate into the cold recycled mixture.

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。

In order to form a skeleton dense structure with good gradation and improve the strength of the mixture. However, this will undoubtedly increase the cost of the cold regeneration structure layer, which needs to be implemented after the economic comparison with the new structure layer.