scholarly journals Experimental Investigation of Rubber Swelling in Bitumen

2020 ◽  
Vol 2674 (2) ◽  
pp. 203-212 ◽  
Author(s):  
Haopeng Wang ◽  
Xueyan Liu ◽  
Panos Apostolidis ◽  
Sandra Erkens ◽  
Athanasios Skarpas
Keyword(s):  
Volume Expansion ◽  
Dominant Role ◽  
Gravimetric Method ◽  
Crumb Rubber ◽  
Mechanical Tests ◽  
Modified Bitumen ◽  
Truck Tire ◽  
Before And After ◽  
Swelling Characteristics ◽  
X Ray Computed

Rubber swelling in bitumen, which is a diffusion-induced volume expansion process, plays a dominant role in the design of crumb rubber modified bitumen binders and their properties development. This study aims to investigate the kinetics of bitumen diffusion into truck tire rubber, the equilibrium swelling characteristics of rubber, and the mechanical properties of rubber before and after swelling at different high temperatures. Fourier transform infrared spectroscopy results indicate that no rubber dissolution happens during the interaction in the temperature range from 160°C to 200°C. Aliphatic compounds from bitumen preferentially diffused into rubber during the swelling process. The diffusion coefficients of bitumen into rubber were determined by the sorption test using the gravimetric method. The diffusion coefficient increases with the increase of temperature in an Arrhenius form. The volume expansion of rubber during swelling was captured by the X-ray computed tomography scan images. Rubber swells faster at the earlier stages, then the expansion rate slows down. The swelling ratio of rubber increased from 1.97 at 160°C to 3.03 at 200°C after 36 h interaction. Mechanical tests by dynamic shear rheometer reveal that swollen rubber becomes softer compared with the dry rubber and exhibits obvious viscoelastic behaviors. With the increase of temperature, the softening and viscous effect are more significant. The obtained parameters can be implemented to swelling and micromechanical models to better predict the binder properties.

scholarly journals Effect of Short Term Aging on Unmodified and Local Crumb Rubber (LCR) Modified Bitumen

2020 ◽  
Vol 18 (02) ◽  
pp. 63-70
Author(s):  
Muhammad Saad Waheed ◽  
Manzoor Elahi
Keyword(s):  
Thin Film ◽  
Phase Angle ◽  
Complex Modulus ◽  
Crumb Rubber ◽  
Dynamic Shear ◽  
Short Term ◽  
Modified Bitumen ◽  
Before And After ◽  
The Difference ◽  
Effects Of Aging

Two grades of bitumen, (60/70 and 80/100), were modified by addition of Local Crumb Rubber (LCR) by weight of base bitumen. To investigate the effects of short-term aging on modified and LCR modified bitumen, Rolling Thin Film Oven (RTFO) test was used to simulate the short term aging. Dynamic shear rheometer (DSR) was used to assess the rheological properties of bitumen, both before and after aging. It was observed that at 65 degree Celcius on aging, the phase angle (sigma) of unmodified bitumen decreased by 3 and 4% for 60/70 and 80/100 bitumen respectively; whereas, for 60/70 LCR modified bitumen, the phase angle (sigma) on RTFO aging decreased by 7% for all LCR content (10, 15 and 20%) by weight of base bitumen. However, on RTFO aging (sigma), values for LCR modified 80/100 bitumen varied across different LCR content and could not be generalized. The complex modulus |G*| of LCR modified 60/70 bitumen increased on aging for both modified and unmodified bitumen at 65C, but with the increase in LCR content, the difference between bitumen aged and un-aged values of |G*| was considerably lowered. An interesting finding was for 80/100 bitumen modified with 20% LCR content by weight, which showed a reduction in |G*| values and an increase in (sigma) values on aging. This shows that to some extent, LCR compensates for the stiffening effects of aging.

scholarly journals Fast Preparation of High-Performance Wood Materials Assisted by Ultrasonic and Vacuum Impregnation

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 567
Author(s):  
Hong Yang ◽  
Mingyu Gao ◽  
Jinxin Wang ◽  
Hongbo Mu ◽  
Dawei Qi
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Mechanical Tests ◽  
Vacuum Impregnation ◽  
Natural Forests ◽  
Ultrasonic Pretreatment ◽  
Fast Growing ◽  
Before And After ◽  
New Material ◽  
Ft Ir

In the absence of high-quality hardwood timber resources, we have gradually turned our attention from natural forests to planted fast-growing forests. However, fast-growing tree timber in general has defects such as low wood density, loose texture, and poor mechanical properties. Therefore, improving the performance of wood through efficient and rapid technological processes and increasing the utilization of inferior wood is a good way to extend the use of wood. Densification of wood increases the strength of low-density wood and extends the range of applications for wood and wood-derived products. In this paper, the effects of ultrasonic and vacuum pretreatment on the properties of high-performance wood were explored by combining sonication, vacuum impregnation, chemical softening, and thermomechanical treatments to densify the wood; then, the changes in the chemical composition, microstructure, and mechanical properties of poplar wood before and after treatment were analyzed comparatively by FT-IR, XRD, SEM, and mechanical tests. The results showed that with ultrasonic pretreatment and vacuum impregnation, the compression ratio of high-performance wood reached its highest level and the MOR and MOE reached their maximums. With the help of this method, fast-growing softwoods can be easily prepared into dense wood materials, and it is hoped that this new material can be applied in the fields of construction, aviation, and automobile manufacturing.

Rheological Findings on Storage Stability for Chemically Dispersed Crumb Rubber Modified Bitumen

2021 ◽  
Vol 305 ◽  
pp. 124768
Author(s):  
Naeem Aziz Memon ◽  
Nur Izzi Md. Yusoff ◽  
Syed Faraz Jafri ◽  
Khawaja Sheeraz
Keyword(s):  
Storage Stability ◽  
Crumb Rubber ◽  
Modified Bitumen

Can crumb rubber modifier effectively replace the use of polymer- modified bitumen in asphalt mixture?

2021 ◽  
pp. 1-16
Author(s):  
Lily D. Poulikakos ◽  
William Buttlar ◽  
Nicolas Schüwer ◽  
Davide Lo Presti ◽  
Tobias Balmer ◽  
...  
Keyword(s):  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Modified Bitumen ◽  
Polymer Modified Bitumen

scholarly journals Study of the Behavior of Structural Materials Treated with Bioconsolidant

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5369
Author(s):  
Yolanda Spairani ◽  
Arianna Cisternino ◽  
Dora Foti ◽  
Michela Lerna ◽  
Salvador Ivorra
Keyword(s):  
Structural Materials ◽  
Mechanical Tests ◽  
Existing Building ◽  
Experimental Campaign ◽  
Stone Materials ◽  
Before And After ◽  
Optical Photomicrograph ◽  
Stone Material ◽  
Artificial Stone ◽  
Non Destructive

In this article, the effectiveness of the bioconsolidation technique applied to degraded structural materials is illustrated as a new method of consolidation and conservation of the existing building heritage in a less invasive way. Satisfactory results have been obtained by an experimental campaign carried out through non-destructive diagnostic tests, static destructive mechanical tests, and microstructural analyses on a series of natural stone material specimens and artificial stone materials before and after the use of bioconsolidants. The consolidated specimens have been tested after three to four weeks after the application of the M3P nutritional solution on each specimen. The effect on the microstructure of this technique has also been observed using scanning electron microscope and optical photomicrograph, the formation of new calcium carbonate crystals promoting the structural consolidation of the materials under examination was observed in all the specimens analyzed.

scholarly journals Tension mechanical properties of recycled glass-epoxy composite material

2012 ◽  
pp. 189-198 ◽  
Author(s):  
Jelena Petrovic ◽  
Darko Ljubic ◽  
Marina Stamenovic ◽  
Ivana Dimic ◽  
Slavisa Putic
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Material ◽  
Composite Materials ◽  
Modulus Of Elasticity ◽  
Epoxy Composite ◽  
Raw Materials ◽  
Mechanical Tests ◽  
Recycled Glass ◽  
Before And After

The significance of composite materials and their applications are mainly due to their good properties. This imposes the need for their recycling, thus extending their lifetime. Once used composite material will be disposed as a waste at the end of it service life. After recycling, this kind of waste can be used as raw materials for the production of same material, which raises their applicability. This indicates a great importance of recycling as a method of the renowal of composite materials. This study represents a contribution to the field of mechanical properties of the recycled composite materials. The tension mechanical properties (tensile strength and modulus of elasticity) of once used and disposed glass-epoxy composite material were compared before and after the recycling. The obtained results from mechanical tests confirmed that the applied recycling method was suitable for glass-epoxy composite materials. In respect to the tensile strength and modulus of elasticity it can be further assessed the possibility of use of recycled glass-epoxy composite materials.

A Study on the Influences of Crumb Rubber Modified Asphalt

2012 ◽  
Vol 204-208 ◽  
pp. 3899-3904
Author(s):  
Lan Yun Chen ◽  
Qing Long You ◽  
Xin Qiu
Keyword(s):  
Laboratory Tests ◽  
Mechanical Characteristics ◽  
Engineering Application ◽  
Crumb Rubber ◽  
Climatic Conditions ◽  
Pavement Performance ◽  
Rubber Content ◽  
Modified Asphalt ◽  
Truck Tire

In order to study the effects of different factors on the performance of crumb rubber modified asphalt, on the basis of many laboratory tests, this article analyzed such factors as types of crumb rubber, fineness, content, mixing temperature and matrix asphalt. Results show that mixed with the crumb rubber, pavement performance of the asphalt has been improved to varying degree. In the engineering application of rubber asphalt, it is suggested that the 20 mesh crumb rubber modified asphalt of truck tire be adopted, with about 16% to 18% of crumb rubber content at about 175°C. As for matrix asphalt, it should be selected according to the different climatic conditions and the mechanical characteristics of the pavement.

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