Effects of Rubber Particles on Rheological and Mechanical Properties of Concrete Containing CaCO3 Nanoparticles

2018 ◽  
Vol 926 ◽  
pp. 109-114
Author(s):  
Li Wang ◽  
Ben Dong Zhao

Lots of waste rubber is being produced in the world and the utilization of it not only mitigate environmental impacts caused by waste rubber disposal but also enhance sustainable development. As a result, rubberized concrete, by incorporation of waste rubber into concrete, should be considered as one of the effective strategies to take advantage of waste rubber. However, problems such as low strengths, weak adhesion between rubber particles and cement pastes, and undesirable pore structures associated with rubberized concrete should be pay more attention to. In this study, the effect of replacement fine aggregate with rubber particles on rheological and mechanical properties of concrete containing CaCO3 nanoparticles was examined through slump, compressive and flexural strength tests. Rubber particles were employed to replace the fine aggregate equally by volume while CaCO3 nanoparticles were used as an equal part of binder by weight. Different sizes and volume contents of rubber particles were evaluated as well as different weight contents of CaCO3 nanoparticles. In addition, corresponding tests were also performed to evaluate the effect of CaCO3 nanoparticles in comparison to concrete specimens without CaCO3 nanoparticles. The results showed that replacement fine aggregates with rubber particles had some influence on the mechanical properties of rubberized concrete, resulting in undesirable findings in terms of compressive and flexural strengths. However, the incorporation of CaCO3 nanoparticles improved mechanical properties of rubberized concrete. Regarding slump test, the rubberized concrete without CaCO3 nanoparticles showed better performance. Considering rheological and mechanical properties, rubberized concrete with 1% CaCO3 nanoparticles presented acceptable results.

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 897
Author(s):  
Heng Li ◽  
Pengpeng Gao ◽  
Fang Xu ◽  
Tao Sun ◽  
Yu Zhou ◽  
...  

This research aimed to investigate the effect of fine aggregate particles on mechanical properties of fly ash-based geopolymer mortar. In this work, seven kinds of river sand particles were designed based on different fine aggregate characteristics. The fineness modulus was adopted to quantitatively describe the gradation of sands. The fluidity, compressive, flexural, and tensile strengths of geopolymer mortar with different sand gradations were analyzed by laboratory tests. Furthermore, the composition and morphology of fly ash-based geopolymer mortar was analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The reasonable gradation range and filling effect of sand were obtained. The results show that fluidity and compressive and flexural strengths of geopolymer mortar both improve with the increase of the fineness modulus, while specific surface area and voidage are opposite. The tensile strength of mortar largely lies on the interface properties between the geopolymer binder and fine aggregates. When the pass rate of the key sieving size 1.18 mm is 75–95%, the pass rate of the key sieving size 0.15 mm is 15–25%, the fineness modulus is 2.2–2.6 and the appropriate filling coefficient of geopolymer paste is around 1.0–1.15, the comprehensive performance of geopolymer mortar is the best. This research paper could provide a basis for the design of geopolymer mortar based on fly ash, and it is of great significance for its popularization and application.


Author(s):  
Kamil Krzywiński ◽  
Łukasz Sadowski ◽  
Damian Stefaniuk ◽  
Aleksei Obrosov ◽  
Sabine Weiß

AbstractNowadays, the recycled fine aggregate sourced from construction and demolition waste is not frequently used in manufacturing of epoxy resin coatings. Therefore, the main novelty of the article is to prepare green epoxy resin coatings modified with recycled fine aggregate in a replacement ratio of natural fine aggregate ranged from 20 to 100%. The microstructural properties of the aggregates and epoxy resin were analyzed using micro-computed tomography, scanning electron microscopy and nanoindentation. The macroscopic mechanical properties were examined using pull-off strength tests. The highest improvement of the mechanical properties was observed for epoxy resin coatings modified with 20% of natural fine aggregate and 80% of recycled fine aggregate. It has been found that even 100% of natural fine aggregate can be successfully replaced using the recycled fine aggregate with consequent improvement of the pull-off strength of analyzed epoxy resin coatings. In order to confirm the assumptions resulting from the conducted research, an original analytical and numerical failure model proved the superior behavior of modified coating was developed.


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1821 ◽  
Author(s):  
Robert Bušić ◽  
Mirta Benšić ◽  
Ivana Miličević ◽  
Kristina Strukar

The paper aims to investigate the influence of waste tire rubber and silica fume on the fresh and hardened properties of self-compacting concrete (SCC) and to design multivariate regression models for the prediction of the mechanical properties of self-compacting rubberized concrete (SCRC). For this purpose, 21 concrete mixtures were designed. Crumb rubber derived from end-of-life tires (grain size 0.5–3.5 mm) was replaced fine aggregate by 0%, 5%, 10%, 15%, 20%, 25%, and 30% of total aggregate volume. Silica fume was replaced cement by 0%, 5%, and 10% of the total cement mass. The optimal replacement level of both materials was investigated in relation to the values of the fresh properties and mechanical properties of self-compacting concrete. Tests on fresh and hardened self-compacting concrete were performed according to the relevant European standards. Furthermore, models for predicting the values of the compressive strength, modulus of elasticity, and flexural strength of SCRC were designed and verified with the experimental results of 12 other studies. According to the obtained results, mixtures with up to 15% of recycled rubber and 5% of silica fume, with 28 days compressive strength above 30 MPa, were found to be optimal mixtures for the potential future investigation of reinforced self-compacting rubberized concrete structural elements.


2015 ◽  
Vol 754-755 ◽  
pp. 427-431
Author(s):  
Shamshinar binti Salehuddin ◽  
Nur Liza Rahim ◽  
Norlia Mohamad Ibrahim ◽  
Siti Aza Nurdiana Tajri ◽  
Mohd Zuhaidi Zainol Abidin

Usage of waste materials as concrete mixture can reduce the waste management crisis in the world. Used tyres were widely researched as an alternative source of aggregates replacement in concrete mixture. This research is to study the behaviour of concrete incorporating rubber tyre crumb as fine aggregate replacement. The workability, compression strength and water absorption of this concrete will be determined and then compared to normal concrete. Motorcycle inner tube will be used as rubber source and it will be shredded to crumbs. Three samples of concrete with rubber as fine aggregates were prepared. Rubber crumbs will be used to replace fine aggregates in 2.5, 5.0 and 7.5% in mass. Normal concrete were prepared separately as control for comparison. Concrete mixture of 1:2:4 and 0.5 of water cement ratio were used. Slump test were done to test the workability of each mix. Twelve sample cubes from (150mm x 150mm x 150mm) each mix were prepared and cured for 7, 14 and 28 days. Compression tests were performed for each mix cube at age 7, 14 and 28 days. Water absorption test were done at age 28 days. Results revealed that rubberized concrete has better workability than normal concrete. They also have smaller compressive value and higher water absorption compared to normal concrete.


2014 ◽  
Vol 911 ◽  
pp. 463-467 ◽  
Author(s):  
Euniza Jusli ◽  
Hasanan M. Nor ◽  
Putra Jaya Ramadhansyah ◽  
Haron Zaiton

This paper sought to evaluate the influences of different levels of waste rubber tyre (rubber granules) as an aggregate replacement in the production of double layer concrete paving blocks (CPBs). Waste rubber tyres were used as an aggregate replacement at the levels of 0%, 10%, 20%, 30%, and 40%. The characteristics of the double layer rubberized CPB were examined via a series of tests. According to the results, the density, porosity, and compressive strength of the double layer rubberized CPB is highly influenced by the percentage of rubber content. The compressive strength test has proven that by using rubber granules as an aggregate, the compressive strength is able to be manipulated. As the percentage of rubber granules increase, the compressive strength will decrease as the amount of solid, load-carrying material reduces. Compressive strength was at its peak when the rubber content was at 10%. 1-4 mm rubber granules were used as a replacement of fine aggregate and 5-8 mm rubber granules as coarse aggregate; both at the level of 40%. As a result, a double layer rubberized CPB with 28-days compressive strength of maximum 28 MPa is produced.


2014 ◽  
Vol 584-586 ◽  
pp. 917-920
Author(s):  
Gang Xue ◽  
Chun Feng Wu

Applying modified waste rubber particle to surface mortar can give full play of the unique characteristics to utilize the waste and decrease environmental pollution. In order to study the application performance of crumb rubber mortar, five different mortar proportions are selected to determine the compressive strength, flexural strength, impact strength and thermal aging strength. The results show that rubber particles mortar possess excellent toughness, impact resistance and heat aging properties.


2019 ◽  
Vol 8 (2) ◽  
pp. 5761-5765

With an objective of saving the environment by providing crumb rubber as an alternative to natural fine aggregate this paper presents a study carried out to find the mechanical properties of rubberized concrete. Rubberized concrete is made up of waste rubber from vehicle tyres and other rubber waste which otherwise is left out polluting the environment. In this paper, 7.5% of crumb rubber (obtained by shredding the vehicle tyres) as an alternative to fine aggregate and 7.5% of fly-ash as an alternative to cement is added with other ingredients of concrete to produce an eco-friendly concrete which can be used economically and effectively for construction along the coastal areas. Various properties like workability, compressive strength, split tensile strength, and flexural strength was carried out on concrete specimens exposed to the natural marine environment along the coast of Visakhapatnam, Andhra Pradesh. The total exposure of concrete specimen was about 150 days, and various specimens were tested at 7, 28, 90, 120 and 150 days, respectively. The test results showed that with a slight compromise in strength, the workability of concrete and resistance to the effect of seawater on the strength of concrete significantly improved with the addition of crumb rubber and fly-ash.


2021 ◽  
Vol 11 (13) ◽  
pp. 6028
Author(s):  
P. Jagadesh ◽  
Andrés Juan-Valdés ◽  
M. Ignacio Guerra-Romero ◽  
Julia M. Morán-del Morán-del Pozo ◽  
Julia García-González ◽  
...  

One of the prime objectives of this review is to understand the role of design parameters on the mechanical properties (Compressive and split tensile strength) of Self-Compacting Concrete (SCC) with recycled aggregates (Recycled Coarse Aggregates (RCA) and Recycled Fine Aggregates (RFA)). The design parameters considered for review are Water to Cement (W/C) ratio, Water to Binder (W/B) ratio, Total Aggregates to Cement (TA/C) ratio, Fine Aggregate to Coarse Aggregate (FA/CA) ratio, Water to Solid (W/S) ratio in percentage, superplasticizer (SP) content (kg/cu.m), replacement percentage of RCA, and replacement percentage of RFA. It is observed that with respect to different grades of SCC, designed parameters affect the mechanical properties of SCC with recycled aggregates.


2018 ◽  
Vol 206 ◽  
pp. 03003
Author(s):  
Haodao Li ◽  
Jingjie Wei ◽  
Wujian Long

The state of GO dispersion is closely related to the properties of graphene oxide (GO)-based cement paste. This paper presents the effect of uniformly dispersed and re-agglomerated GO on the rheological and mechanical properties. The results showed that, compared to re-agglomerated GO cement paste, the yield stress and plastic viscosity of uniformly dispersed GO cement paste were higher. Moreover, the compressive and flexural strengths of uniformly dispersed GO pastes were higher than those of re-agglomerated GO pastes. Porosity analysis using mercury intrusion porosimetry showed that the well-dispersed GO can inhibit the formation of large-diameter pores and optimize the pore size distribution better than the re-agglomerated GO.


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