1,721,046 research outputs found
Resilient Modulus of Recycled Aggregates Obtained by Means of Dynamic Tests in a Triaxial Apparatus
No full textThe main objective of this experimental research is to prove the hypothesis of the use of recycled materials (C&D) in building road subbases by means of a comparative study which investigates the resilient behaviour of unbound aggregate blends. The results given by the investigation clearly prove that the blend made of recycled materials has shown a resilient behaviour very similar to that of a typically frictional material, such as a virgin granular material coming from quarry aggregates. A low susceptibility to water and a marked influence of confinement pressure on the blend stiffness are the properties which prove this similar behaviour
INDAGINE SULLE CARATTERISTICHE MECCANICHE DEI CONGLOMERATI BITUMINOSI RICICLATI A FREDDO
No full textExperimental investigation of the dynamic behaviour of asphalt concrete treated with photocatalytic mortars
No full textThe increase of environmental atmospheric pollution can be dealt with various methodologies, including the use of environmentally friendly materials based on photocatalytic reactions. Therefore, in the field of road construction, asphalt concrete pavements could be combined with a superficial layer of cement mortar containing photocatalytic substances in order to directly subject them to pollutants coming from vehicular traffic exploiting the wide surface area of road pavements in contact with the atmosphere. The aim of this study is to analyze the mechanical characteristics of the heterogeneous system asphalt concrete – photo-catalytic mortar in order to identify its actual behaviour and compare it with that of sole asphalt concrete. Modulus and fatigue dynamic tests have been carried out on specimens taken from porous asphalt concrete manufactured slabs over which photocatalytic mortars, prepared with different percentages of water, had pre-viously been poured. Investigations proved that the percentage of water used in the photocatalytic mortars af-fects the mixture fluidity, which influences both the level of penetration of the mortar through pores and the mechanical performances of road pavement
Verifica strutturale di pavimentazioni stradali in cubetti di pietra eseguita con analisi FEM
No full textLow-temperature tensile behaviour of asphalt binders: Application of loading time–temperature–conditioning time superposition principle
No full textThermal cracking of bituminous layers is one of the main modes of failure for asphalt pavements. This
distress is highly related to the rheological properties of asphalt binders. The purpose of this study
was to investigate the low-temperature behaviour of asphalt binders by performing Direct Tension Tests
(DTTs) according to Superpave specification. The DTT results were analyzed and compared in terms of
trend of stress–strain curve instead of conventional failure stress or failure strain values. Through the
analysis of stress–strain diagram, it was possible to evaluate the effects of temperature, elongation rate
and conditioning time on the rheological properties of binders. Particular attention was paid to the conditioning
time variable as it was observed that the stiffness of the binder changes with time when it is
stored isothermally at low temperature due to the physical hardening phenomenon.
To this end, a modified superposition effects principle, which also includes the conditioning time in
addition to the temperature and elongation rate variable, has been proposed. Finally, this principle
allowed the authors to find an analytical model capable of describing the rheological properties of asphalt
binders as functions of the three considered test variables
- …
