1. Old road survey

冷再生技術(shù)適用于大部分瀝青混凝土舊路大修與改建工程。需要對舊路進行詳細(xì)的調(diào)查，主要包括以下內(nèi)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）對舊路結(jié)構(gòu)和歷年修補改造情況進行調(diào)查，了解路面病害情況，包括變形、裂縫、邊緣破壞等。

(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）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(fù)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 status and bearing capacity of the old road, and determine the necessity of reusing the old road base for cold regeneration.

（3）對舊路結(jié)構(gòu)層進行鉆芯取樣，以確定舊路結(jié)構(gòu)層的厚度及各層材料的工程特性。

(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、材料組成設(shè)計

2. Material composition design

通過試驗分析，我們認(rèn)為冷再生層的性能與混合料級配有著顯著而密切的關(guān)系。如若舊料中4.75mm以上的粒料含量過低(<40%)，則需加入部分級配的新骨料；若舊料中4.75mm>80%)，則會導(dǎo)致細(xì)料(特別是<0.6mm的集料)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(xì)集料，以便形成具有良好級配的骨架密實結(jié)構(gòu)，提高混合料的強度。但這無疑都會提高冷再生結(jié)構(gòu)層的造價，需與新建的結(jié)構(gòu)層進行經(jīng)濟比較以后再實施。

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、瀝青混凝土路面現(xiàn)場冷再生技術(shù)的施工工藝

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

冷再生技術(shù)的施工工藝按加水在撒布外摻劑的前后順序分為先加水施工和后加水施工兩種。經(jīng)過對試驗段鋪筑效果分析后發(fā)現(xiàn)，先加水施工的冷再生結(jié)構(gòu)層更容易壓實成型，且表面均勻、平整、光滑，壓實度容易滿足要求。建議在水源充足，時間允許條件下采用先加水施工工藝。

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）瀝青混凝土路面現(xiàn)場冷再生施工前的準(zhǔn)備工作

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

（2）瀝青混凝土路面現(xiàn)場冷再生施工工藝

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

冷再生技術(shù)可以充分利用舊路資源，對舊路面層及基層進行再生利用形成新的路面基層。是對舊路推除重建的完全否定，既要挖除舊路重做結(jié)構(gòu)層，又要把舊路廢料運走堆放。二者相比，前者直接和簡潔，經(jīng)濟效益顯著。在路面結(jié)構(gòu)設(shè)計理念上，廢舊瀝青的再生利用將會改變過去以剛性材料做基層的設(shè)計觀點。是瀝青路面再生利用養(yǎng)護技術(shù)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.