Mix designs for cold recycled pavement materials considering local weather and traffic conditions

Abstract

Cold recycling is a road rehabilitation procedure/technique, where the reclaimed road material from rehabilitated pavements is recycled completely and used in the new structure with only small contents of new road materials. This is done preferably in-situ to save time, costs and environment. However, internationally various mix design procedures were developed since decades resulting in diverse contents of bituminous binders (emulsion or foamed bitumen) and/or mineral binders (cement or hydraulic road binder). The different material compositions result in diverse mechanical material properties and demand for different pavement designs. Based on an international comparison of cold recycling experience, commons and differences were elaborated during European CoRePaSol project funded by the CEDR. The existing definitions of various cold recycled materials were assessed and supplemented in order to introduce clear material definitions in future European specification documents. Based on intensive test campaigns suitable assessment procedures are proposed to address these materials. At the same time based on local traffic and weather conditions as well as availability of source materials, a decision model is proposed for choosing the optimum cold recycling material for the given rehabilitation project.

Cold Recycled Asphalt Mixture using 100% RAP with Emulsified Asphalt‐Recycling Agent as a New Pavement Base Course

“…When compared to results obtained by Mollenhauer et al [11] and Raschia et al [12], ITS values of the current research were lower. In this case, besides the Portland cement content in the study of Mollenhauer et al [11], the compaction method used by them was the gyratory compaction, which may have provided a better compaction and, consequently, lower air voids.…”

“…When compared to results obtained by Mollenhauer et al [11] and Raschia et al [12], ITS values of the current research were lower. In this case, besides the Portland cement content in the study of Mollenhauer et al [11], the compaction method used by them was the gyratory compaction, which may have provided a better compaction and, consequently, lower air voids. However, when compared to the research of Ma et al [10], which used the Marshall compactor, the ITS values of the current research were similar, although the curing time was shorter.…”

Assessment of two laboratory design methods for CIR mixtures with bitumen emulsion based on static and gyratory compaction

“…Rather than a single standard, different transportation administrations have developed different guidelines and recommendations [22][23][24][25][26]. Additionally, many companies in the pavement recycling sector employ their own manuals [27,28] In this context, different specimen compaction methods, curing procedures, testing methods, and specifications are used, depending on the requirements determined by the transportation administrations of various countries [24,[29][30][31][32][33][34][35]38] (Table 1). In recent years, the gyratory compaction method has become increasingly popular, as it has been shown to achieve the closest simulation of field compaction [39].…”

“…related to the Modified Proctor test result), they do not limit the air-void content (as is the case for HMA mixtures). However, a few specifications and technical references indicate that the air-void content of laboratory CIR specimens usually ranges from 8% to 15% [6,7,18,21,30,31,34,39]. Regarding the field compaction of CIR mixtures, technical reports indicate that a well-compacted mixture generally has an air-void content between 12% and 15%, and the density ranges from 2000 to 2100 kg/m 3 [40][41][42][43].…”

Estudo de mistura asfáltica reciclada a frio produzida com 100% de revestimento asfáltico fresado e agente de reciclagem emulsionado.

“…Importante frisar que para o ensaio com a energia Proctor modificada não foi realizada a curva de compactação em função da umidade, uma vez que tentou-se simular como ocorreria a compactação com o material no estado em que se encontrava vindo de campo. Os resultados de massa específica e volume de vazios são apresentados na Figura 42.ANDRADE, 2017;MOLLENHAUER et al,2016). Esse efeito poderia estar associado não apenas à cura, visto que, muitas vezes, essas misturas são usinas com a incorporação de fíler ativo, como a cal ou cimento Portland, além do agente de reciclagem ou da emulsão asfáltica.…”