scholarly journals Fatigue Performance and Multiscale Mechanisms of Concrete Toughened by Polymers and Waste Rubber

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Bo Chen ◽  
Liping Guo ◽  
Wei Sun

For improving bending toughness and fatigue performance of brittle cement-based composites, two types of water-soluble polymers (such as dispersible latex powder and polyvinyl alcohol powder) and waste tire-rubber powders are added to concrete as admixtures. Multiscale toughening mechanisms of these additions in concretes were comprehensively investigated. Four-point bending fatigue performance of four series concretes is conducted under a stress level of 0.70. The results show that the effects of dispersible latex powder on bending toughness and fatigue life of concrete are better than those of polyvinyl alcohol powder. Furthermore, the bending fatigue lives of concrete simultaneously containing polymers and waste rubber powders are larger than those of concrete with only one type of admixtures. The multiscale physics-chemical mechanisms show that high bonding effect and high elastic modulus of polymer films as well as good elastic property and crack-resistance of waste tire-rubber powders are beneficial for improving bending toughness and fatigue life of cementitious composites.

2020 ◽  
Vol 40 (10) ◽  
pp. 815-822
Author(s):  
Magdy A. M. Ali ◽  
Heba A. Raslan ◽  
Khaled F. El-Nemr ◽  
Medhat M. Hassan

AbstractThe engagement of waste tires rubber as source of raw materials for different applications can be a partial solution to the great environmental problems caused by these products. In this study, waste tire rubber was devulcanized using both mechano–chemical and microwave methods. This process was achieved using different concentrations of 2-mercapto benzothiazole disulfide (MBTS) and tetramethylthiuram disulfide (TMTD) as a devulcanizing agent and different microwave devulcanizing times. The optimum content of both MBTS, TMTD and suitable microwave treatment time to make continuous film were noted. The devulcanized waste rubber was then added, at different concentrations, to virgin styrene–butadiene rubber (SBR). The thermal properties and dynamic mechanical behaviors were investigated for all blends. The thermal analysis proved that natural and styrene butadiene rubber are the main two constituents of the waste tire rubber utilized in this study. The mechanical behavior of the SBR blends remarkably improved by using 20 phr waste rubber (WR) devulcanized by 2 phr MBTS and by exposure for 2.2 min to microwaves. Storage modulus, tearing strength and tension set behaviors notably improved for all SBR/WR blends by irradiating with gamma ionizing radiation with a dose of 100 kGy and further improvement could be attained by increasing the dose up to 200 kGy.


2002 ◽  
Vol 84 (3) ◽  
pp. 622-631 ◽  
Author(s):  
Amit K. Naskar ◽  
Anil K. Bhowmick ◽  
S. K. De

2018 ◽  
Vol 6 (3) ◽  
pp. 035703 ◽  
Author(s):  
Tej Singh ◽  
Mukesh Kumar Rathi ◽  
Amar Patnaik ◽  
Ranchan Chauhan ◽  
Sharafat Ali ◽  
...  

2007 ◽  
Vol 28 (7) ◽  
pp. 2234-2238 ◽  
Author(s):  
D. García ◽  
J. López ◽  
R. Balart ◽  
R.A. Ruseckaite ◽  
P.M. Stefani

2010 ◽  
Vol 75 (6) ◽  
pp. 845-853 ◽  
Author(s):  
Hassan Mousavi ◽  
Abdorrahman Hosseinifar ◽  
Vahdat Jahed

The influence of pH, adsorbent dose, initial Cu(II) concentration and contact time on the removal of Cu(II) from aqueous solution by the batch adsorption technique using waste tire rubber ash as a low-cost adsorbent was investigated. The adsorption equilibrium was achieved after 2 h at pH 4-6, the optimum for the adsorption of Cu(II) ions. A dose of 1.5 g/L of adsorbent was sufficient for the optimum removal of copper ions. The experimental data were analyzed by the Langmuir and Freundlich isotherms and the corresponding sorption constants were evaluated. The adsorption kinetics data were fitted by a first-order equation. The cost of removal is expected to be quite low, as the adsorbent is cheap and easily available in large quantities. The present study showed that waste tire rubber ash was capable of removing copper ions from industrial wastewater samples.


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