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.

在對道路進行養護工作時，我們需要對原先的道路進行調查，以確保在冷再生機租賃后其進行道路養護工作的順利進行。

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、舊路調查

1、 Survey of old roads

冷再生技術適用于大部分瀝青混凝土舊路大修與改建工程。先需要對舊路進行詳細的調查，主要包括以下內容:

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、對舊路結構和歷年修補改造情況進行調查，了解路面病害情況，包括變形、裂縫、邊緣破壞等。

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、對舊路進行彎沉檢測，以分析舊路的破壞狀況和承載能力，確定重復利用舊路基層進行冷再生的必要性。

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、對舊路結構層進行鉆芯取樣，以確定舊路結構層的厚度及各層材料的工程特性。

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、材料組成設計

2、 Material composition design

通過試驗分析，我們認為冷再生層的性能與混合料級配有著顯著而密切的關系。如若舊料中4.75mm以上的粒料含量過低，則需加入部分級配的新骨料;

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;

若舊料中4.75mm以上的粒料含量過高，則會導致細料對空隙的填充不足，混合料強度偏低，則需在冷再生混合料中加入部分級配的細集料。

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.

以便形成具有良好級配的骨架密實結構，提高混合料的強度。但這無疑都會提高冷再生結構層的造價，需與新建的結構層進行經濟比較以后再實施。

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.