scholarly journals Influence of the Compaction Method in the Volumetric Design of Cold Recycled Mixtures with Emulsion

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1309
Author(s):  
Guillermo Flores ◽  
Juan Gallego ◽  
Lucía Miranda ◽  
José Ramón Marcobal
Keyword(s):  
Mechanical Properties ◽  
Water Content ◽  
Bulk Density ◽  
Asphalt Mixtures ◽  
Combined Effect ◽  
Recycled Asphalt ◽  
New Approach ◽  
Two Factors ◽  
Gyratory Compaction ◽  
Compaction Method

Compaction of cold asphalt mixtures is a subject that has not been thoroughly studied, and, for this reason, requires new efforts from researchers to have a better understanding. Unlike hot mixtures, cold mixtures and mainly recycled mixtures require specific considerations for compaction. There is a lack of consensus about the methodology to select the optimum premix water and emulsion contents. In the absence of specific regulations, the use of soil tests or hot mixtures procedures is common. For these reasons, this investigation’s main goal was to evaluate two compaction methods used to design cold recycled mixtures with emulsion: the modified Proctor procedure and the gyratory compaction. It was concluded that both methods could be useful to study compactability since consistent results were obtained by applying the maximum bulk density criterion. However, the higher bulk densities achieved, the smaller specimens used, and the suitability of the gyratory specimens to be later tested for mechanical properties make them preferable to the modified Proctor samples. A new approach has been proposed using iso-density lines on dual-axis premix water content-emulsion content graphs that facilitates the study of the influence on compactability of these two factors combined. These contributions can alleviate the laboratory works during the design of cold recycled asphalt mixtures and contribute to a more in-depth knowledge of the combined effect of premix water and emulsion contents on the compactability of cold recycled mixtures with emulsion.

Influence of short and long term aging on chemical, microstructural and macro-mechanical properties of recycled asphalt mixtures

2014 ◽  
Vol 51 ◽  
pp. 414-423 ◽  
Author(s):  
Lily D. Poulikakos ◽  
Salomé dos Santos ◽  
Moises Bueno ◽  
Simon Kuentzel ◽  
Martin Hugener ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Asphalt Mixtures ◽  
Recycled Asphalt ◽  
Short And Long Term

scholarly journals Self-Healing Analysis of Half-Warm Asphalt Mixes Containing Electric Arc Furnace (EAF) Slag and Reclaimed Asphalt Pavement (RAP) Using a Novel Thermomechanical Healing Treatment

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2502 ◽  
Author(s):  
José Manuel Lizárraga ◽  
Juan Gallego
Keyword(s):  
Mechanical Properties ◽  
Microwave Heating ◽  
Asphalt Pavement ◽  
Electric Arc ◽  
Asphalt Mixtures ◽  
Self Healing ◽  
Arc Furnace ◽  
Recycled Asphalt ◽  
Indirect Tensile ◽  
Eaf Slag

Nowadays, the self-healing of asphalt pavements promoted by microwave radiation heating energy is gaining attention and strength in the scientific community. However, most of these studies are only conceptual and, thus, remain shrouded in uncertainty regarding technology development, economy, and application effect. Therefore, there are several efforts underway to offer more effective assisted healing treatments that are capable of overcoming such uncertainties. This paper aims to assess and quantify the healing performance rates (HR) of half-warm recycled asphalt (HWRA) mixtures containing electric arc furnace (EAF) slag and total recycled asphalt pavement (RAP) rates. To this end, a novel assisted thermomechanical healing treatment (i.e., a recompaction-based technique and microwave heating energy) was put forward to promote the potential healing effect of this treatment on the mechanical properties of the asphalt mixtures. In order to do this, three microwave heating temperatures (25 °C, 60 °C, and 80 °C) and three mechanical recompaction levels (0, 25, and 50 gyrations) were selected. After that, the healing performance rates (%, HR) of the asphalt mixtures were calculated by repeated indirect tensile strength (ITS) and indirect tensile stiffness modulus (ITSM). The results indicated that the 8% EAF slag mixture was found to provide significant microwave heating energy savings by up to 69% compared with the benchmark 100% RAP mixture, and, at the same time, it experienced a remarkable stiffness recovery response of 140% of the initial mechanical properties. These findings encourage greater confidence in promoting this innovative thermomechanical-based healing treatment for in-situ surface course asphalt mixtures of road pavements.

scholarly journals KUALITAS FISIK PELET AYAM BROILER PERIODE AKHIR DENGAN PENAMBAHAN FESES TERNAK DAN BAHAN PEREKAT YANG BERBEDA

2016 ◽  
Vol 13 (1) ◽  
pp. 33
Author(s):  
Indra Rahmana ◽  
Dewi Ananda Mucra ◽  
Dewi Febrina
Keyword(s):  
Specific Gravity ◽  
Water Content ◽  
Bulk Density ◽  
Block Design ◽  
Angle Of Repose ◽  
Cattle Feces ◽  
Two Factors ◽  
Pellet Form ◽  
Tapioca Flour

The study aimed to know the physical quality of pellets for finisher period added different feces and adhesive matter. The experiment design was randomized complety block design  factorial  (RCBD) with two factors and three replications. The first factor was feces (goat feces, cattle feces, buffalo feces) and the second factor was adhesive matter (tapioca flour, eeg white, sago flour). Physical observation were water content, specific gravity, bulk density, compressed bulk density, angle of repose, and the durability of pellet. The result showed that addition type feces influenced water content, specific gravity, bulk density, compressed bulk density, angle of repose and the durability of pellet form. The result showed that addition adhesive matter influenced bulk density, compressed bulk density, the durability of pellet form.Interaction the addition of cattle feces and different adhesive matter in water content, specific gravity, compressed bulk density, angle of repose and the durability of pellet. Interaction buffalo feces and tapioca flour best quality. 

A Hybrid Model to Predict the Gyratory Compaction of Hot Mixed Asphalt

2019 ◽  
Author(s):  
Teng Man
Keyword(s):  
Hybrid Model ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Compaction Process ◽  
Particle Rearrangement ◽  
Compaction Behavior ◽  
Grain Size Distributions ◽  
Gyratory Compaction

The compaction of asphalt mixture is crucial to the mechanical properties and the maintenance of the pavement. However, the mix design, which based on the compaction properties, remains largely on empirical data. We found difficulties to relate the aggregate size distribution and the asphalt binder properties to the compaction behavior in both the field and laboratory compaction of asphalt mixtures. In this paper, we would like to propose a simple hybrid model to predict the compaction of asphalt mixtures. In this model, we divided the compaction process into two mechanisms: (i) visco-plastic deformation of an ordered thickly-coated granular assembly, and (ii) the transition from an ordered system to a disordered system due to particle rearrangement. This model could take into account both the viscous properties of the asphalt binder and grain size distributions of the aggregates. Additionally, we suggest to use the discrete element method to understand the particle rearrangement during the compaction process. This model is calibrated based on the SuperPave gyratory compaction tests in the pavement lab. In the end, we compared the model results to experimental data to show that this model prediction had a good agreement with the experiments, thus, had great potentials to be implemented to improve the design of asphalt mixtures.

Hydrogels as Antibacterial Biomaterials

2018 ◽  
Vol 24 (8) ◽  
pp. 843-854 ◽  
Author(s):  
Weiguo Xu ◽  
Shujun Dong ◽  
Yuping Han ◽  
Shuqiang Li ◽  
Yang Liu
Keyword(s):  
Mechanical Properties ◽  
Drug Delivery ◽  
Tissue Engineering ◽  
Water Content ◽  
Oxygen Permeability ◽  
Structural Diversity ◽  
High Water ◽  
Clinical Applications ◽  
High Water Content ◽  
Biomedical Field

Hydrogels, as a class of materials for tissue engineering and drug delivery, have high water content and solid-like mechanical properties. Currently, hydrogels with an antibacterial function are a research hotspot in biomedical field. Many advanced antibacterial hydrogels have been developed, each possessing unique qualities, namely high water swellability, high oxygen permeability, improved biocompatibility, ease of loading and releasing drugs and structural diversity. In this article, an overview is provided on the preparation and applications of various antibacterial hydrogels. Furthermore, the prospects in biomedical researches and clinical applications are predicted.

Mechanical Properties with Respect to Water Content of Host–Guest Hydrogels

2021 ◽  
Vol 54 (17) ◽  
pp. 8067-8076 ◽  
Author(s):  
Motofumi Osaki ◽  
Shin Yonei ◽  
Chiharu Ueda ◽  
Ryohei Ikura ◽  
Junsu Park ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Content

Study on mechanical properties and damage evolution of carbonaceous shale under triaxial compression with acoustic emission

2021 ◽  
pp. 105678952199119
Author(s):  
Kai Yang ◽  
Qixiang Yan ◽  
Chuan Zhang ◽  
Wang Wu ◽  
Fei Wan
Keyword(s):  
Mechanical Properties ◽  
Acoustic Emission ◽  
Water Content ◽  
Damage Evolution ◽  
Damage Assessment ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Damage Variable ◽  
Natural State ◽  
Carbonaceous Shale

To explore the mechanical properties and damage evolution characteristics of carbonaceous shale with different confining pressures and water-bearing conditions, triaxial compression tests accompanied by simultaneous acoustic emission (AE) monitoring were conducted on carbonaceous shale rock specimens. The AE characteristics of carbonaceous shale were investigated, a damage assessment method based on Shannon entropy of AE was further proposed. The results suggest that the mechanical properties of carbonaceous shale intensify with increasing confining pressure and degrade with increasing water content. Moisture in rocks does not only weaken the cohesion but also reduce the internal friction angle of carbonaceous shale. It is observed that AE activities mainly occur in the post-peak stage and the strong AE activities of saturated carbonaceous shale specimens appear at a lower normalized stress level than that of natural-state specimens. The maximum AE counts and AE energy increase with water content while decrease with confining pressure. Both confining pressure and water content induce changes in the proportions of AE dominant frequency bands, but the changes caused by confining pressure are more significant than those caused by water content. The results also indicate that AE entropy can serve as an applicable index for rock damage assessment. The damage evolution process of carbonaceous shale can be divided into two main stages, including the stable damage development stage and the damage acceleration stage. The damage variable increases slowly accompanied by a few AE activities at the first stage, which is followed by a rapid growth along with intense acoustic emission activities at the damage acceleration stage. Moreover, there is a sharp rise in the damage evolution curve for the natural-state specimen at the damage acceleration stage, while the damage variable develops slowly for the saturated-state specimen.

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