Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Warm mix asphalt: an overview

Performance of Warm Mix Asphalt containing Sasobit®: State-of-the-art

Pavement engineering materials: Review on the use of warm-mix asphalt

Asphalt is the most recycled material in the USA at a re-use rate of 99%. However, by average only 10–20% reclaimed asphalt pavement (RAP) is used in a given mix design and large part of the RAP is degraded for use in lower value applications. The amount of RAP in asphalt mixtures can be significantly increased with the application of good RAP management practice, readily available modern production technologies and advanced knowledge of mix design. This paper summarises the state-of-the-art approaches for increasing the amount of RAP in asphalt mixtures above 40%. The production challenges and common pavement distresses of very high RAP content mixtures are identified and methods to optimise the mix design as well as production technology in order to allow manufacturing of such sustainable mixtures are described. The best practices for RAP management and economic benefits of high RAP use are also discussed.

Review of very high-content reclaimed asphalt use in plant-produced pavements: state of the art

Coarse aggregate is widely used in the unbound granular layers (UGM) of roads, in particular as granular sub-base and base. However, although various studies have been conducted on these materials, their mechanical behaviour still has not been properly characterized, in Portuguese conditions, especially due to reasons connected to the heterogeneity of the rock masses from which they come from. This has special importance for Portuguese pavement technology. In the attempt of contributing for a better knowledge of that behaviour, a work was developed having the aim of obtain the mechanical characterization and the establishment of behaviour models for crushed materials coming from different lithologies, namely limestone and granite, susceptible of being used as UGM. This paper describes the principal results obtained from the work and pointing out the main directives that can be extracted from it, in terms of the global behaviour of a road pavement.

https://repositorium.sdum.uminho.pt/bitstream/1822/18675/1/5-ICTI_2008.pdf

The use of cyclic triaxial tests in the characterization of portuguese UGM

This work is being funded by QREN, in the scope of the project “Energy Efficiency and Environmental Design of Bituminous Mixtures and Reducing Emissions of Greenhouse Gases” (QREN-SI 090528), 
attributed to the company Elevo with the collaboration of the University of Minho. Thanks 
are also due to the Foundation for Science and Technology (FCT) for funding allocated through the PhD Scholarship SFRH/BD/85448/2012

https://repositorium.sdum.uminho.pt/bitstream/1822/39150/1/2140-M2D2015_paper5705.pdf

A mechanical analysis of asphalt recycled mixtures produced with high recycling rates

Quadro de Referencia Estrategica Nacional e a entidade financiadora Agencia
Nacional da Inovacao pelo financiamento ao projeto numero 38915 Projeto de I&D Tropical-PAV

https://repositorium.sdum.uminho.pt/bitstream/1822/43259/1/2333-Paper%20revisto%20-%20AVALIA%c3%87%c3%83O%20DE%20ESTRUTURAS%20DE%20PAVIMENTOS%20RODOVI%c3%81RIOS%20ATRAV%c3%89S%20DE%20PISTA%20E%20SIMULADOR%20DE%20ENSAIOS%20ACELERADOS%20%c3%80%20ESCALA%20REAL.pdf

Avaliação de estruturas de pavimentos rodoviários através de pista e simulador de ensaios acelerados à escala real

The mechanical properties of bituminous mixtures depend on the adhesion between mastic and aggregate, as well as on the cohesion within the mastic. These properties vary as a function of the composition of the bituminous mixture, of the chemical and physical features of the aggregate and bitumen and of the condition under which the mixing is carried out. It is thus fundamental to develop an adhesion test, which is of easy execution and, at the same time, represents correctly the bituminous mixture and its mechanical behaviour, essentially the aggregate-mastic adhesion. The test described here simulates the behaviour of a small representative specimen of the bituminous material subject to increasing tension or shear force, inducing rupture of the aggregate-mastic bond. The specimens have a prismatic shape and comprise a single large piece of aggregate between two layers of mastic. The efficiency of the aggregate-mastic bond will be evaluated by the necessary force to rupture the specimen and by the form of rupture. The results obtained from this test will not only allow the features which most influence the adhesion of mastic to aggregate to be established, but also reveal the best aggregate-fines-binder combinations as a function of the type of aggregate and bituminous mixture. For the covering abstract see ITRD E117840.

/pdf/development-of-a-laboratory-test-for-characterization-of-2tnsmzpytq.pdf

Development of a laboratory test for characterization of asphalt-aggregate adhesion

Microsurfacing asphalt mixtures are a preventive maintenance technology comprising the application of a slurry (produced with a modified asphalt emulsion), aggregate, filler, and water on top of an existing pavement at ambient temperature. Although it is a widely used technology, further studies on the mix design procedures are necessary to ensure an adequate composition. Thus, this study contributes to developing an improved mix design procedure for microsurfacing asphalt mixtures. Different mixtures were prepared, and the influence of the type and amount of asphalt emulsion and the amount of added water and filler (cement) on the characteristics of the mixture were evaluated. Two preliminary tests, referred to as the “pizza test” and the “ball test”, were proposed to determine the initial proportions of added water and cement in the mixture, respectively. Then, consistency, cohesion, and shaking abrasion tests were performed to determine the optimum content of each component and evaluate their influence on the mixture characteristics. The results showed that these tests are essential to optimize the mix composition, even though it was found that the mix design of microsurfacings is a complex task because the mixture is a system with chemical interactions strongly influenced by its composition.

/pdf/development-and-application-of-a-microsurfacing-mix-design-3piwi8ek.pdf

Hugo Manuel Ribeiro Dias da Silva

Papers

The use of cyclic triaxial tests in the characterization of portuguese UGM

A mechanical analysis of asphalt recycled mixtures produced with high recycling rates

Avaliação de estruturas de pavimentos rodoviários através de pista e simulador de ensaios acelerados à escala real

Development of a laboratory test for characterization of asphalt-aggregate adhesion

Development and Application of a Microsurfacing Mix Design Method to Assess the Influence of the Emulsion Type