Within the framework of a sustainable development, manufacturing bituminous mixtures while reducing energy and using less new aggregates and new bitumen may be considered as an important topic, according to the quantities of asphalts mixtures produced for creating and maintaining road networks. This work aims to study the interest and the potential problems when coupling the warm mix asphalt technology (WMA) and the use of high ratio of reclaimed asphalt pavement (RAP) in the mixture. Initially, a study on managing RAP is performed, aiming to show that separating RAP aggregates in several fractions leads to a higher control of RAP in terms of homogeneity. Homogeneity of RAP is a key point for increasing recycling rates. The present study coupling WMA and RAP is based on the French design method for manufacturing asphalt concretes, which includes gyratory compaction tests, French wheel tracking tests, complex modulus tests and fatigue tests. However, the French design method does not take into account the physical and chemical aging of bituminous mixtures with time. As we consider that coupling WMA and RAP may lead to aging problems, it was decided to use an aging process before performing the standard tests. The results show that a WMA containing a high ratio of RAP has good performances according to the standard relative to this material, whatever the test. However, this material tends to be more sensitive to fatigue than hot and warm mixes without RA

Resumo: Na pavimentação, é comum tratar os dados obtidos em ensaios à luz de conceitos da estatística clássica, que consideram que um conjunto de dados possui distribuição Normal e utilizam os parâmetros média e desvio padrão na análise dos dados. O presente trabalho se propõe a verificar a aderência à distribuição Normal de dados oriundos de alguns ensaios de materiais para pavimentação: densidades aparente e real e absorção do agregado graúdo, densidade aparente e volume de vazios de corpos de prova de mistura asfál-tica. Utilizaram-se os testes de Kolmogorov-Smirnov (K-S) e Shapiro-Wilk (S-W), por meio do pacote estatístico SPSS. Cada ensaio foi realizado pelo menos 30 vezes por um mesmo operador, utilizando os mesmos equipamentos. Observou-se convergência entre os testes K-S e S-W para cinco dos seis ensaios avaliados. Os mesmos ensaios também foram realizados por nove laboratórios, em amostras semelhantes; e foi utilizado apenas o teste S-W. Os resultados do teste S-W com relação ao conjunto de dados obtidos por um mesmo operador e por nove operadores foram semelhantes. Estas análises estatísticas contribuíram para a decisão com relação à escolha das ferramentas estatísticas utilizadas no Programa Interlaboratorial de Agregados e Misturas Asfálticas da Rede Asfalto N/E. DOI:10.4237/transportes.v21i1.566.Palavras-chave: normalidade; análise estatística; materiais para pavimentação.Abstract: For pavement materials evaluation, it is common to treat laboratorial test data with classical statistical concepts, considering that a data set has a normal distribution, and therefore using the parameters average and standard deviation. The present work aims to verify if the normal distribution can be applied for the results of some tests, such as bulk specific gravity, apparent specific gravity and absorption for coarse aggregates, bulk specific gravity and air voids for hot mixture asphalt samples. The Kolmogorov-Smirnov (K-S) e Shapiro-Wilk (S-W) tests were used with the SPSS. Each test was carried out at least 30 times by the same operator using the same equipment. There was convergence between the two normality tests for five of the six parameters. Then, the tests were also performed by nine different laboratories using similar samples; and only S-W test was used. These statistical analyses support the decision about the statistical tools used in the Interlaboratory Program of Aggregates and Asphalt Mixtures of the North-Northeast Asphalt Network.

Within the framework of the European Project SUP&R ITN a PhD thesis is carried out to study the durability of the combination of high rates of reclaimed asphalt pavement and warm mix asphalt technologies. For this purpose the complex modulus and fatigue resistance of three different asphalt mixtures, including surfactant modified and foamed warm mix asphalts, combined with reclaimed asphalt pavement (RAP) has been studied. The extra value is given by the application of an ageing procedure based on the oxidation of compacted materials in laboratory. It follows the recommendations of the RILEM TC-ATB TG5, which distinguishes between short and long term ageing. Fourier Transform InfraRed (FTIR) tests were carried out on the extracted bitumens to quantify the oxidation levels. An increase of the norm and a decrease of the phase angle of |E*| at 15°C 10Hz with ageing and RAP addition are experienced for all the mixtures. Similar to what happens with the slopes of the fatigue laws that tend as well to increase. A consistent correlation is observed between these evolutions and the evolution of the carbonyl index calculated. This reflects a trend towards more brittle materials with predicted fatigue live improved for low strain levels but reduced for high strain levels. In general, the tendency is similar for all procedures, so the use of warm technologies combined with high RAP amounts may need to be considered.