Characteristics of Polymers and Polymer-Modified Binders

Author(s):  
F. Bonemazzi ◽  
V. Braga ◽  
R. Corrieri ◽  
C. Giavarini ◽  
F. Sartori

The properties of a number of polymers commonly proposed for polymer-modified bitumens (PMBs) were studied to suggest a way to select the polymer suitable for the required application; the prediction of the performance in the final application would allow bypass of the tests on PMBs and asphalt mixtures. Rheological and mechanical tests were performed on both raw materials and PMBs containing 5 percent polymer. Tensile dynamic mechanical test analyzer hardness, tensile properties, and tension set tests were conducted on polymers; the tendency of the polymers to absorb aromatic oil was also determined to simulate their swelling in the PMBs. Rheometer dynamic tests, R&B, penetration, and elastic recovery were carried out on PMBs. Rheometer dynamic parameters, R&B, penetration, and elastic recovery were measured on the bitumen. The experimental data confirm that selected tests on polymers can give good information about the polymer contribution to PMBs' performances.

2021 ◽  
Vol 6 (4) ◽  
pp. 58
Author(s):  
Ana Dias ◽  
Hugo Silva ◽  
Carlos Palha ◽  
Joel Oliveira

When temperatures drop to significantly low levels, road pavements are subjected to thermally-induced stresses, resulting in the appearance of thermal cracking, among other distresses. In these situations, polymers can be used as asphalt binder modifiers to improve certain asphalt binder properties, such as elastic recovery, cohesion, and ductility. Polymers also minimize some of the problems of asphalt mixtures, such as thermal and fatigue cracking and permanent deformation. This work’s objective was to study the behavior of asphalt mixtures at low temperatures, mainly when using modified binders. Thus, three binders were selected and tested: a standard 50/70 penetration grade bitumen and two polymer-modified binders (PMB), obtained by adding, respectively, 2.5% and 5.0% of styrene–butadiene–styrene (SBS) in the 50/70 pen grade bitumen. Then, the PMBs were incorporated into stone mastic asphalt mixtures (namely SMA 11), which were subjected to low-temperature mechanical tests based on the most recent European Standards. The asphalt binders and mixtures evaluated in this work were tested for thermal cracking resistance, creep, elastic recovery, cohesive strength, and ductility strength. Overall, it is concluded that the studied asphalt mixtures with PMB, with just 2.5% SBS, performed adequately at low temperatures down to −20 °C.


2018 ◽  
Vol 3 (11) ◽  
pp. 37-41
Author(s):  
Tawfeeq W. Mohammed ◽  
Dalmn Yaseen Taha ◽  
Rafal R. Abdul-Ilah

This research has focused on the evaluation of raw materials that used in the wings of modern airplane. These materials either would be fiberglass, carbon-fiber or aramid based composites like Kevlar. These common materials have been selected and evaluated depending on experimental data obtained from mechanical tests. These tests include: hardness, tensile strength and bending stress. The tests based on ASTM standards for mechanical properties. The results show increasing in the hardness value of graphite-epoxy by 9% comparing with that of fiberglass and by 18% comparing with that of Kevlar-epoxy. The results also show an increasing in the maximum tensile strength of graphite-epoxy by 2.9 times to that of fiberglass and by 5.5 times to that of Kevlar-epoxy. Furthermore, the results of bending stress test show increasing of the maximum strength of Kevlar-epoxy by 30% comparing to that of glass fiber and by 75% comparing to that of graphite-epoxy.


2013 ◽  
Vol 575-576 ◽  
pp. 543-549
Author(s):  
Hai Xiong Wang ◽  
Ji Bin Li ◽  
Yong Hu Lv

Thermal microimprint is a promising technology for polymer microstructure, so it is used to form V-groove on the surface of optical devices. However, it is difficult to control the size accuracy of V-groove because of the elastic recovery of polymer. In order to solve the problem, the influencing factors on the polymer elastic recovery were firstly analyzed in this article. Then, it was proposed that the embossment height of mold should be modified according to the depth of V-groove and the modifier formulas should be constructed based on the theory of polymer viscoelasticity. In the end, the optimal technological parameters of thermal microimprint were obtained through the thermal imprint experiments, and the embossment height of the mold after modification was calculated according to the experimental data, and thus a new mold was produced as to verify the accuracy of the modifier formulas. The results showed that the approach of modification could not only ensure dimension accuracy of V-groove, by keeping the error within 1μm, but also shorten the imprint time, consequently the efficiency of thermal microimprint would be improved.


Author(s):  
Johanna Banck-Burgess

This chapter challenges traditional views on Iron Age dress. Recent research has greatly enhanced our understanding of how textiles were manufactured in Iron Age Europe. The variety of qualities, textures, techniques, raw materials, colours, and cuts give insights into the detailed knowledge of the craftspeople involved. Textiles used for dress, blankets, or furniture fittings were appreciated not only for their appearance, but also for the quality of the work. In everyday life, their optical qualities were used to express and signal gender, social roles and status, while the labour expended on textiles found in wealthy burials underlines both the status of the deceased and the extent of conspicuous consumption in funerary rituals—for instance, for wrapping grave furniture and goods. The chapter also looks at experimental data showing how labour-intensive textile production was, and the types of clothing and accessories found in different archaeological contexts or depicted in visual representations.


2012 ◽  
pp. 189-198 ◽  
Author(s):  
Jelena Petrovic ◽  
Darko Ljubic ◽  
Marina Stamenovic ◽  
Ivana Dimic ◽  
Slavisa Putic

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.


2015 ◽  
Vol 1100 ◽  
pp. 142-146
Author(s):  
Jiří Bydžovský ◽  
Tomáš Melichar ◽  
Nikol Žižková

Within the research presented in this article the attention was paid to the study of microstructure of lightweight and decorative renders. The composition of these renders was modified using alternative raw materials in amount of 5 % substituting the finest aggregate fractions. For evaluation of microstructure and its changes the combination of three methods SEM, XRD and DTA was used. Samples for the analysis were prepared from 90-day old specimens. The reason was the evaluation of material structural changes within the mid-term scale because considering the character and amount of used raw materials including the results of physical-mechanical tests no more significant changes were assumed in a short-term period. The performed analyses showed only inessential changes in microstructure of modified materials in comparison with the results of physical-mechanical tests.


2012 ◽  
Vol 630 ◽  
pp. 473-478 ◽  
Author(s):  
Fei Wan ◽  
Guo Xi Li ◽  
Jing Zhong Gong ◽  
Bao Zhong Wu

To change the status of time-consuming and over-reliance on technicians in mechanical system alignment process, the ACP technology is presented. The mapping between alignment process parameters and dynamic parameters was established through contact theory to build the agent model for parts. While the second mapping between dynamic parameters and machine dynamic characteristics is calculated by dynamic simulation software to conduct computational experiments. Experimental data is analyzed in order to implement data mine, optimize the alignment process, guide technician alignment, modify the theory mapping and improve the alignment efficiency.


2021 ◽  
Author(s):  
Omid Daqiq ◽  
Fred W. Wubs ◽  
Ruud R. M. Bos ◽  
Baucke van Minnen

Abstract The study aims to optimise surgical management for mandibular body fractures by application of finite element method (FEM) with verification from polymeric model tests. The study investigates two issues regarding the application of osteosynthesis plates for mandibular body fractures: the effect of miniplate positioning and mandibular body height decrease. Computed tomography (CT) images of cadaveric mandibles with heights of resp. 21, 15, and 10 mm were used to create a FEM-model with a unilateral straight-line fracture, fixated with a standard commercially available 6-hole 2 mm titanium miniplate. Outcomes were compared with a series of mechanical tests with polymeric models fixed in a customized device and loaded with a mechanical test bench. Firstly, the study illustrates that the optimal plate position appears to be the upper border. Secondly, lower mandibular height increases instability and requires a stronger fixation. Thirdly, optimal fracture reduction is essential for gaining stability. In conclusion, FEM and polymeric testing outcomes of unilateral non-comminuted fractures were highly comparable to the current opinions in mandibular fracture treatment. In future, the FEM may be used to predict the treatment of more complex fractures. However, more analysis needs to be conducted to say whether FEM alone is sufficient for fracture analysis.


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