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Journal ArticleDOI: 10.1080/14680629.2019.1643396

Experimental study on the pore structure variation of self-compacting rubberised concrete under fatigue load

04 Mar 2021-Road Materials and Pavement Design (Informa UK Limited)-Vol. 22, Iss: 3, pp 716-733
Abstract: In this paper, the correlation analysis between mechanical fatigue properties and pore structure was performed on the self-compacting rubberised concrete (SCRC). Four-point bending destructive and ...

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Topics: Bending (53%)

10 results found

Open accessJournal ArticleDOI: 10.1016/J.CONBUILDMAT.2019.117282
Jie Xu1, Jie Xu2, Ziyi Yao2, Guang Yang2  +2 moreInstitutions (2)
Abstract: Crumb rubber concrete (CRC) with waste rubber as aggregate has emerged in the past decades. In this paper, the microstructure, numerical microstructure simulation, pore structure features, mechanical properties and structural members of CRC are reviewed from microscale, mesoscale and macroscopic perspectives. The ductility, toughness, damping ratio, fatigue resistance, impact resistance, and durability of the concrete are improved, which is widely used in road engineering and shows a promising future application in structural engineering. Future research should combine the current situation of multi-scale research of CRC and promote further multi-scale research and the application of CRC.

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Topics: Crumb rubber (57%)

36 Citations

Journal ArticleDOI: 10.1016/J.CONBUILDMAT.2021.122547
Chaofeng Liang1, Chaofeng Liang2, Cai Zhedong2, Huixia Wu3  +4 moreInstitutions (3)
Abstract: Chloride ingress and resulting steel corrosion are the main reasons leading to durability degradation. A body of literature on chloride transport and steel corrosion in recycled aggregate concrete (RAC) is currently available, but a systematic review has been lacking. This paper presents a critical review of chloride transport in RAC, and the induced steel corrosion behaviour and cracking patterns of reinforced RAC are introduced. Related modification methods are further discussed. The results showed that the incorporated recycled aggregate (RA) increased chloride ingress in RAC, and a time-dependent characteristic was observed for the chloride diffusion coefficient. The lower RA properties led to higher chloride ingress in preparing RAC when RA substitution rates were the same; the induced environmental damage accelerated chloride ingress in RAC. Incorporating RA increased the steel corrosion risk and shortened the initial corrosion time of reinforced RAC, and the cracking pattern of reinforced RAC was different from the cracking pattern of reinforced natural aggregate concrete. Removing and enhancing the adhered old mortar of RA improve the properties of RAC, and various modification methods can be employed to improve the resistance to chloride ingress and steel corrosion in RAC. In particular, a CO2-curing treatment, which is eco-friendly, is recommended for improving the RA and RAC properties. The study of chloride ingress and steel corrosion in ultra-high performance RAC and 3D-printed RAC should be a focus in further studies.

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Topics: Chloride (55%), Corrosion (54%)

21 Citations

Journal ArticleDOI: 10.1016/J.MEASUREMENT.2020.107832
01 Aug 2020-Measurement
Abstract: To study the change of concrete internal structure before and after stress, the meso-mechanical experiment of concrete was conducted using CT technology and a portable dynamic loading device. And CT images of the concrete internal structure change under uniaxial compression condition were obtained. For establishing the relationship between the micro-structure and macro-mechanics of concrete, an improved differential box counting (IDBC) method was proposed to calculate the fractal dimension of the CT images, which could describe the entire damage process of concrete. By comparing the fractal dimension calculated by the two methods, it can be seen that the fitting error of the fractal dimension obtained by the IDBC method is reduced by nearly 50% compared with that obtained by the DBC method. Afterward, the damage variable expression was established on the basis of the fractal dimension. The research results indicated that the damage variable established in this research can describe the damage process of concrete well. That is, the damage variable equaled to 0 during the first scan, and before reaching the peak stress, the damage variable showed a trend of increasing first and then decreasing. After the concrete specimen has completely fractured, the damage variable reached a maximum of one. Furthermore, through extracting the area of CT image cracks region at different stress stages, the relationship between the area of cracks region and the stress was studied. It appeared that the CT technology and fractal theory are promising methods to analyze the evolution of the concrete damage process under static uniaxial compression.

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Topics: Box counting (56%), Fractal (54%), Fractal dimension (54%)

8 Citations

Journal ArticleDOI: 10.1016/J.ISTRUC.2020.07.069
Afsaneh Valizadeh1, Fatemeh Hamidi1, Farhad Aslani1, Farhad Aslani2  +1 moreInstitutions (3)
01 Oct 2020-Structures
Abstract: Self-compacting rubberised concrete (SCRC) has been received great attention in recent years as an environmental remediation to not only fabricate sustainable and durable civil engineering structures, but also to take the very first steps towards resolving the issue of waste tyres abandoned in the nature. As a step forward in evaluating the structural performance of SCRC, the current research investigates the impacts of specimen size and specimen shape on the compressive and tensile strengths of SCRC containing 0%, 10%, and 20% crumb rubber aggregates (i.e., CSCC, SCRC10 and SCRC20) by means of both experimental and fracture mechanics-based theoretical approaches. Cubic specimens with dimension of 100 m m and 150 m m for assessing the compressive strength, cylindrical specimens with dimension of Φ 100 × 200 m m and Φ 150 × 300 m m for the both compressive and splitting tensile strengths measurement, and prism specimen with dimension of 100 × 100 × 400 m m for the flexural strength measurement were casted. The analytical study was performed based on the modified size effect low (MSEL) and adjusting its parameters by applying the experimental results, to establish the correlation between the mechanical properties of SCRC with the geometry of the structural element. Moreover, the relationship between the modulus of rupture and compressive strength of the SCRC has been also pioneered, based on the design codes recommended for the self-compacting concrete. The results show difference between the compressive strength of the cube-shaped specimen with standard cylinder specimen is more significant for mixes with 20% rubber aggregates rather than that for the SCRC with less than 20% rubber aggregate. Increasing the rubber aggregates content led to the significant size effect on the tensile strength of SCRC. The MSEL model predictions are in acceptable agreement for cubic specimen with the experimental data obtained for the CSCC and SCRC10 and for cylindrical specimen, the impact of varying the specimen size on the compressive strength weakened by increasing the rubber aggregate content.

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Topics: Compressive strength (60%), Ultimate tensile strength (57%), Flexural strength (55%) ... show more

4 Citations

Journal ArticleDOI: 10.1016/J.CONBUILDMAT.2021.122380
Yingli Gao1, Wenjuan Zhou1, Wei Zeng, Ganpeng Pei1  +1 moreInstitutions (1)
Abstract: In this study, the mix proportion of self-compacting road concrete with ternary cementitious materials was optimized by incorporating nano-silica particles to improve its flexural fatigue performance The filling property and compressive strength were selected as evaluating indicators to design L9(33) orthogonal test, and then four kinds of mix proportions were selected to prepare the nano-modified self-compacting concrete (SCC) according to the results of grey relational analysis and comprehensive weighting method The four-point flexural fatigue tests were conducted to establish the probabilistic fatigue equations of nano-modified SCC based on the two-parameter Weibull distribution with survival rates of 50% and 95%, respectively The modification mechanism was revealed with the help of scanning electron microscopy and X-ray diffraction phase analysis The results indicate that the optimal mix proportion of self-compacting road concrete could be obtained when nano-silica accounts for 1% of the mass of cementitious materials The specimens with 1% nano-silica particles showed the best flexural fatigue performance, with the reduction factor of flexural strength increased by 15%–50% and the sensitivity of fatigue life to the stress levels decreased by 21%–97% at survival rate of 50% The nanoparticles provided a physical filling effect and facilitated the formation of low-density calcium silicate hydrate gel, filling the internal micro-pores to make the structure more compact Nano-silica improved the flexural fatigue performance of self-compacting road concrete to a certain extent

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Topics: Flexural strength (62%), Compressive strength (52%), Cementitious (52%)

4 Citations


30 results found

Journal ArticleDOI: 10.1016/S0008-8846(00)00370-7
Sidney Diamond1Institutions (1)
Abstract: The conditions that must be met for mercury intrusion porosimetry (MIP) measurements to provide valid estimates of the pore size distribution of porous solids are reviewed. Evidence is presented indicating that these conditions are not satisfied in cement-based systems. In cement systems, nearly all of the mercury intrusion is held up until pressure corresponding to the threshold diameter is reached; subsequently, large and small pores are filled indiscriminately. Air voids, in sizes up to several hundred micrometers, are present in most pastes in substantial volume, unless the pastes were mixed under vacuum; these air voids are also not intruded until the threshold pressure is reached, and are recorded as fine (ca. 0.1 μm) pores. It is concluded that MIP measurements are useful only to provide threshold diameters and intrudable pore space measurements, which can serve as comparative indices for the connectivity and capacity of the pore systems in hydrated cements. MIP measurements should be abandoned as measures of the actual pore sizes present.

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Topics: Porosimetry (61%)

911 Citations

Journal ArticleDOI: 10.1016/J.WASMAN.2008.01.015
01 Dec 2008-Waste Management
Abstract: Due to the increasingly serious environmental problems presented by waste tires, the feasibility of using elastic and flexible tire-rubber particles as aggregate in concrete is investigated in this study. Tire-rubber particles composed of tire chips, crumb rubber, and a combination of tire chips and crumb rubber, were used to replace mineral aggregates in concrete. These particles were used to replace 12.5%, 25%, 37.5%, and 50% of the total mineral aggregate's volume in concrete. Cylindrical shape concrete specimens 15 cm in diameter and 30 cm in height were fabricated and cured. The fresh rubberized concrete exhibited lower unit weight and acceptable workability compared to plain concrete. The results of a uniaxial compressive strain control test conducted on hardened concrete specimens indicate large reductions in the strength and tangential modulus of elasticity. A significant decrease in the brittle behavior of concrete with increasing rubber content is also demonstrated using nonlinearity indices. The maximum toughness index, indicating the post failure strength of concrete, occurs in concretes with 25% rubber content. Unlike plain concrete, the failure state in rubberized concrete occurs gently and uniformly, and does not cause any separation in the specimen. Crack width and its propagation velocity in rubberized concrete are lower than those of plain concrete. Ultrasonic analysis reveals large reductions in the ultrasonic modulus and high sound absorption for tire-rubber concrete.

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Topics: Properties of concrete (70%), Crumb rubber (59%), Aggregate (composite) (58%) ... show more

408 Citations

Journal ArticleDOI: 10.1016/J.WASMAN.2010.02.005
Maria Antonietta Aiello1, F. Leuzzi1Institutions (1)
01 Aug 2010-Waste Management
Abstract: The main objective of this paper is to investigate the properties of various concrete mixtures at fresh and hardened state, obtained by a partial substitution of coarse and fine aggregate with different volume percentages of waste tyres rubber particles, having the same dimensions of the replaced aggregate. Workability, unit weight, compressive and flexural strength and post-cracking behaviour were evaluated and a comparison of the results for the different rubcrete mixtures were proposed in order to define the better mix proportions in terms of mechanical properties of the rubberized concrete. Results showed in this paper were also compared to data reported in literature. Moreover, a preliminary geometrical, physical and mechanical characterization on scrap tyre rubber shreds was made. The rubberized concrete mixtures showed lower unit weight compared to plain concrete and good workability. The results of compressive and flexural tests indicated a larger reduction of mechanical properties of rubcrete when replacing coarse aggregate rather than fine aggregate. On the other hand, the post-cracking behaviour of rubberized concrete was positively affected by the substitution of coarse aggregate with rubber shreds, showing a good energy absorption and ductility indexes in the range observed for fibrous concrete, as suggested by standard (ASTM C1018-97, 1997).

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238 Citations

Journal ArticleDOI: 10.1016/J.JCLEPRO.2015.08.046
Abstract: This paper presents the results of an experimental investigation to comparatively study the depth of chloride penetration, resistance to acid attack and macrocell corrosion of rubberized concrete and control mix concrete. Waste tire rubber in the form of crumb rubber was replaced for natural fine aggregates from 0% to 20% in multiples of 2.5%. Analytical studies were performed with Abaqus and the results were compared with compressive and flexural strength obtained in the laboratory. It was observed that the depth of chloride penetration of the concrete with 2.5–7.5% crumb rubber was lower than or equal to the control mix concrete. In the water absorption test of acid attacked specimens, gradual increase was observed as the percentage of crumb rubber was increased. After acid attack, more losses in the weight and compressive strength were observed in the control mix concrete than the rubberized concrete. There was no presence of sufficient corrosion in the specimens from the macrocell corrosion test. The analytical results have shown the same trend for compressive strength and flexural tensile strength as obtained in the laboratory. It can be concluded that the rubberized concrete is highly resistant to the aggressive environments and can be implemented in the areas where there are chances of acid attack.

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Topics: Crumb rubber (62%), Compressive strength (58%), Aggregate (composite) (55%) ... show more

201 Citations