THE DEPENDENCE OF THE MECHANICAL PROPERTIES OF SAND-FILLER-ASPHALT MIXTURES ON TEMPERATURE, RATE OF LOADING AND BULK DENSITY OF AGGREGATE

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.

Download Full-text

Effect of RAP on the mechanical properties of registered asphalt mixtures in Flanders

Life-Cycle of Engineering Systems ◽

10.1201/9781315375175-46 ◽

2016 ◽

pp. 399-405

Author(s):

J. Anthonissen ◽

W. Van Den Bergh ◽

J. Braet

Keyword(s):

Mechanical Properties ◽

Asphalt Mixtures

Download Full-text

Mechanical Properties and Thermal Conductivity of Lightweight Clay Bricks Fabricated with a Powdered Marble Dust Additive

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.777.465 ◽

2018 ◽

Vol 777 ◽

pp. 465-470

Author(s):

Sutas Janbuala ◽

Mana Eambua ◽

Arpapan Satayavibul ◽

Watcharakhon Nethan

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Compressive Strength ◽

Water Absorption ◽

Bulk Density ◽

Firing Temperature ◽

Apparent Porosity ◽

Clay Brick ◽

Clay Bricks ◽

Marble Dust

The objective of this study was to recycle powdered marble dust to improve mechanical properties and thermal conductivity of lightweight clay bricks. Varying amounts of powdered marble dust (10, 20, 30, and 40 vol.%) were added to a lightweight clay brick at the firing temperatures of 900, 1000, and 1100 °C. When higher quantities of powdered marble dust were added, the values of porosity and water absorption increased while those of thermal conductivity and bulk density decreased. The decrease in apparent porosity and water absorption were also affected by the increase in firing temperature. The most desirable properties of the clay bricks were obtained for the powdered marble dust content of 40 vol.% and firing temperature 900 °C: bulk density of 1.20 g/cm3, compressive strength 9.2 MPa, thermal conductivity 0.32 W/m.K, and water absorption 22.5%.

Download Full-text

Effect of Moisture Content on Selected Physical and Mechanical Properties of Two Varieties of Tigernut (Cyperus spp)

Journal of Food Research ◽

10.5539/jfr.v2n6p24 ◽

2013 ◽

Vol 2 (6) ◽

pp. 24

Author(s):

A. S. Oyerinde ◽

A. P. Olalusi

Keyword(s):

Mechanical Properties ◽

Moisture Content ◽

Bulk Density ◽

Average Length ◽

Physical And Mechanical Properties ◽

Static Friction ◽

Angle Of Repose ◽

Tuber Weight ◽

Porosity Coefficient ◽

Effect Of Moisture

<p>The effect of moisture content on some physical and mechanical properties of two varieties of tigernuts (<em>Cyperus esculentus</em>) was investigated. These properties include: geometric dimensions, linear dimensions, 1000 tuber weight, bulk density, tuber size, sphericity, angle of repose, porosity, coefficient of static friction and compressive strength. The moisture content levels used were 20, 25, 30, 35 and 40% wet basis (wb), and the two tigernut varieties used were yellow and brown types. The linear dimension, geometric diameter, sphericity, 1000- tuber weight, bulk density and angle of repose in both varieties increased with increasing moisture content. The average length, width and thickness of the yellow variety increases more than the brown variety at the determined moisture contents. True density of the yellow variety increased while the brown variety decreased with increase in moisture content. The porosity of the yellow variety reduces with increase in moisture content from 45.95 at 20% mc to 42.4 at 40% mc, while the brown variety decreased from 42.72 at 20% mc to 30.77 at 40% moisture content. The yellow variety had bigger size tubers than the brown variety and this has serious implications in packing, handling and transportation issues.</p>

Download Full-text

The Effect of Lithium Alumina Silicate Phases on Elastic Modulus of Porcelain Tiles

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.92.188 ◽

2014 ◽

Vol 92 ◽

pp. 188-193 ◽

Cited By ~ 1

Author(s):

Tuna Aydin ◽

Alpagut Kara

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

Liquid Phase ◽

Bulk Density ◽

Bending Strength ◽

Physical And Mechanical Properties ◽

Raw Material ◽

Closed Porosity ◽

Low Viscosity ◽

Porcelain Tiles

Spodumene, which is a lithium alumina silicate, has been used as a raw material in the production of thermal shock resistant whitewares and sanitarywares. The presence of spodumene results in enhancement of mullitization and imparts better physical and mechanical properties to ceramics. In this study, the influence of Lithium alumina silicate phases on the mechanical properties of standard porcelain stoneware body was investigated. Especially solid-solid reactions were observed between spodumene and quartz or spodumene and clay. These solid-solid reactions bring about a newly formed lithium alumina silicate (LAS) phases. Spodumene allows the development of a low viscosity liquid phase and results in a decrease in closed porosity, also with increase in bulk density, bending strength and elastic modulus.

Download Full-text

The Effect of Ageing on Chemical and Mechanical Properties of Asphalt Mortar

Applied Sciences ◽

10.3390/app8112231 ◽

2018 ◽

Vol 8 (11) ◽

pp. 2231 ◽

Cited By ~ 4

Author(s):

Ruxin Jing ◽

Xueyan Liu ◽

Aikaterini Varveri ◽

Athanasios Scarpas ◽

Sandra Erkens

Keyword(s):

Mechanical Properties ◽

Asphalt Mixtures ◽

Pavement Performance ◽

Frequency Sweep ◽

Carbonyl Index ◽

Mineral Particles ◽

Tension Tests ◽

Ftir Spectrometry ◽

Diffusion Paths ◽

Asphalt Mortar

Asphalt mortar is a mixture of bitumen, filler, and sand. Mortar plays an important role in asphalt mixtures as it serves as the adhesive between the coarser aggregates. Due to the effect of bitumen ageing, the chemical and mechanical properties of asphalt mortar evolve with time. The mortar becomes more brittle and prone to cracking, thus leading to inferior pavement performance. In this study, Fourier transform infrared (FTIR) spectrometry was used to quantify changes in the chemical functional groups related to ageing and to calculate the carbonyl and sulfoxide indices. In addition, frequency sweep tests and uniaxial tension tests were performed by means of dynamic shear rheometer (DSR) tests to determine evolution of the stiffness and strength due to ageing. Two different oven ageing protocols were used to evaluate the effect of fine mineral particles on bitumen ageing. The protocols differed with respect to the order of ageing and mixing of the constituents. The results showed that both the chemical and mechanical properties of mortars significantly changed with ageing. Specifically, the carbonyl index, stiffness, and strength of the mortar increased. Under the same ageing conditions, a higher ageing level was observed for mortars produced by first mixing and then ageing compared to the mortars produced by mixing aged bitumen with filler and sand. This could be due to the presence of sand and filler particles, which resulted in an increased length of diffusion paths and consequently a slower ageing process.

Download Full-text

Evaluation of Short-Term Aging Protocol for Asphalt Mixtures

Applied Sciences ◽

10.3390/app9142783 ◽

2019 ◽

Vol 9 (14) ◽

pp. 2783 ◽

Cited By ~ 1

Author(s):

Sirin ◽

Paul ◽

Kassem ◽

Ohiduzzaman

Keyword(s):

Mechanical Properties ◽

Asphalt Pavement ◽

Road Construction ◽

Asphalt Mixtures ◽

Pavement Performance ◽

Design Stage ◽

Construction Site ◽

Short Term ◽

Compaction Processes

Asphalt mixtures are subjected to short-term aging during the production, placement, and compaction processes. Proper evaluation of asphalt pavement performance relies on the accurate characterization of asphalt mixtures during the design stage. In this study, three different loose asphalt mixtures often used in Qatar were evaluated to develop a laboratory short-term aging procedure. Sample mixtures 1 and 3 were collected from a construction site, while mixture 2 was obtained from an asphalt plant. Virgin aggregates and binders were also collected to reproduce the mixtures in the laboratory. Laboratory-produced mixtures were conditioned at 135 °C using various time durations. The mechanical properties of laboratory-produced mixtures were compared to those of mixtures produced on site. The results of the mechanical and binder testing demonstrated that the proper short-term aging protocol for asphalt mixtures often used in road construction in the State of Qatar would involve heating asphalt mixtures for 4 h at 135 °C before laboratory compaction.

Download Full-text

Impact of Preheating Temperatures and RAP Characteristics on the Activation of RAP Binder

Applied Sciences ◽

10.3390/app10238378 ◽

2020 ◽

Vol 10 (23) ◽

pp. 8378

Author(s):

Yifu Meng ◽

Liping Liu

Keyword(s):

Mechanical Properties ◽

Asphalt Pavement ◽

Asphalt Mixtures ◽

Reclaimed Asphalt Pavement ◽

Reclaimed Asphalt ◽

Central Plant ◽

Preheating Temperature

Reclaimed asphalt pavement (RAP) is preheated to 120 °C or lower in hot central plant recycling due to specification and equipment limitations. However, the insufficient activation of reclaimed asphalt (RA) caused by low preheating temperature may affect the final properties of reclaimed asphalt mixtures (RAM) and lead to insufficient utilization of RA binder. This study evaluated the influence of preheating temperature and aging of RA binder on binder activation by producing specimens with 100% RAP. The volumetric and mechanical properties of specimens were analyzed to reflect the effect of activation. The results indicate that preheating temperature has a significant impact on the activation of RA binder. Regardless of the source of RAP, RA binder can be highly activated at 180 °C, while the degree of activation decreases significantly at 120 °C. By using an artificial RAP with different degrees of aging, the aging of RA binder is found to be harmful to activation only when the preheating temperature is low (such as 120 °C). Hence, if the equipment is capable of doing so, it is better to raise the preheating temperature of RAP to improve the activation of RA binder, especially for binder with a higher degree of aging.

Download Full-text

Fracture and mechanical properties of asphalt mixtures containing granular polyethylene terephthalate (PET)

Construction and Building Materials ◽

10.1016/j.conbuildmat.2020.120410 ◽

2020 ◽

Vol 259 ◽

pp. 120410 ◽

Cited By ~ 1

Author(s):

Amin Shams Esfandabad ◽

Seyed Mohsen Motevalizadeh ◽

Reza Sedghi ◽

Pooyan Ayar ◽

Seyed Mohammad Asgharzadeh

Keyword(s):

Mechanical Properties ◽

Polyethylene Terephthalate ◽

Asphalt Mixtures

Download Full-text

Effect of Alumina (Al2O3) to the Properties of Whiteware Porcelain

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1010.194 ◽

2020 ◽

Vol 1010 ◽

pp. 194-199

Author(s):

Hamdan Yahya ◽

Aspaniza Ahmad ◽

Ismail Ibrahim

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Water Absorption ◽

Bulk Density ◽

Physical And Mechanical Properties ◽

Porcelain Body ◽

The Other ◽

Alumina Content ◽

Crystalline Phases ◽

Mullite Phase

The effect of Al2O3 to the properties of whiteware porcelain such as water absorption, bulk density, flexural strength and crystalline phases were studied systematically. The result shows that the addition of alumina at maximum 5 wt.% in porcelain bodies increased the flexural strength of the fired bodies which can reach 55.5 MPa, 30% higher than 0.0% alumina content. However, slight decrease in the other physical and mechanical properties was observed with Al2O3 addition higher than 5 wt.%, which is believed to be due to increased corundum phase compared to mullite phase in porcelain body.

Download Full-text