Effect Of Rubber Particle Size Research Articles

Mechanical strength of rubberized concrete: Effects of rubber particle size, content, and waste fibre reinforcement

Concrete production, ubiquitous in global construction, exerts significant environmental strain, notably through cement manufacturing's carbon footprint and natural sand depletion. As a response, researchers are exploring eco-friendly alternatives, including Waste Tyre Rubber (WTR) aggregates which replace natural sand in concrete. This study investigates the impact of WTR particle sizes (ranging from 0.2 to 4 mm) and volumetric replacements (0–54 %) on Rubberised Concrete Mortar (RuCM) and Rubberised Concrete (RuC) mechanical properties. Additionally, Waste Tyre Steel Fibre (WTSF) reinforcement effects (volume dosage between 0 % and 3 %) are examined and compared with Commercial Steel Fibre (CSF). The study optimizes RuCM and RuC mixes via particle packing theory, incorporating Ground Granulated Blast Furnace Slag (GGBS) and Fly Ash (FA) as cement replacements. Mechanical tests reveal the compressive and flexural strength reduces with an increasing WTR dosage, attributed to the inherent softness of WTR and the weak interfacial bonding between WTR particles and surrounding matrix. Utilizing an optimized RuC mixture with a 10 % WTR replacement yields substantial mechanical improvements, showcasing a remarkable 195 % surge in compressive strength and a noteworthy 61 % elevation in flexural strength over conventional concrete (CC). However, when compared to the control mix devoid of rubber replacement, there is a modest reduction of 16 % in compressive strength and 4 % in flexural strength. Moreover, the incorporation of WTSF reinforcement proves beneficial in mitigating compressive strength losses post rubber particle inclusion and brings about a substantial increase in flexural strength with 3 % volumetric additions. Quantitative analysis reveals the reinforcement effect from WTSF is comparable to the effect of CSF reinforcement. These findings underscore the intricacies and potential opportunities in harnessing WTR and WTSF for the development of resilient and sustainable concrete formulations.

Effect of rubber particles on mechanical properties of calcareous sand under large displacement shear

To reveal the influence of rubber particles on the mechanical properties of calcareous sand under the large-displacement shear effects of earthquakes and waves, indoor ring shear tests were conducted on rubber particle-calcium sand mixtures. The effects of rubber particle size and content on the mechanical properties of calcareous sand were studied via indoor ring shear test. Then, based on PFC3D, a numerical model of a ring shear test that can restore the shape of calcareous sand particles is established, and a mesomechanical analysis of mixed sand is carried out. The results showed that the effect of the rubber particle content on the crushing characteristics and strength of calcareous sand was significant and that the effect of the particle size was small. The rubber content causes a gradual decrease in the peak strength and particle crushing rate and increases the deformation stability of the mixed sand. The softening coefficient and relative crushing rate were significantly reduced to 0.01–0.06 and 0.28–1.2%, respectively, at 40% rubber content. The numerical simulations and experimental results were in good agreement. An increase in the rubber content significantly influences chain development, which explains the macroscopic mechanical properties of mixed sand at the fine level.

Eco-friendly concrete produced with recycled materials

Using recycling materials to produce concrete become a major subject for research in the last decades. The work aims to examine the effects of the partial replacement of fine aggregate by recycled rubber. In addition to studying the influence of two different fiber types on mechanical properties of concrete with rubber replacement. Three types of rubbers that differ in particle size are used to find the effect of rubber particle size on compressive strength, splitting tensile strength, and flexure strength of the concrete mix. Two waste fiber types are used which are Rope Waste Fiber (RWF) and Steel Waste Fiber (SWF). The findings showed that minimizing the rubber particle size improved the mechanical properties. Also, using two types of waste fiber (rope and steel) together led to improve compressive strength.

Experimental study on preparation and properties of low content rubberized geopolymer mortar

• Different blending ratios of raw materials have a great influence on the properties of geopolymer. • Effects of rubber particle size on the working and mechanical properties of RGRM has been studied. • Long term high temperature curing will reduce the compressive and flexural strength of RGRM. • The morphology of rubber particles in RGRM is characterized by XRD and SEM. • The developed rubber geopolymer repair mortar has good economic and environmental evaluation. With the continuous increase of infrastructure construction, the supply of river sand is becoming increasingly scarce in recent years. Partially replacing river sand with waste rubber as fine aggregate has attracted extensive attention. Many studies were involved in the physical and mechanical properties of rubber mixed in ordinary mortar. However, there are few studies on the property changes of rubber blended into geopolymer mortar. In this study, a new type of rubberized geopolymer mortar (RGM) using rubber as fine aggregate replacement of 5 % river sand was investigated. Four kinds of rubber particle sizes are 4 mm, 1.7 mm, 0.83 mm and 0.27 mm respectively. The fluidity, compressive strength, flexural strength and microstructure of these RGMs were tested and analyzed in detail. Results show that the addition of rubber particles slightly reduces the fluidity of the corresponding geopolymer mortar (i.e., 22.4 cm), the fluidity of studied RGMs are within 17.6–21.5 cm. The compressive and flexural strength of RGMs also decrease with an increase of rubber particle size. However, RGMs have relatively high early strength, and their highest 1-d compressive and flexural strength can reach 47.2 MPa and 7.2 MPa, as well as 51.3 MPa and 8.2 MPa, respectively, at curing temperatures of 25 °C and 80 °C, implying that high-temperature curing can improve their early strengths. It is also found that the compressive and flexural strength of RGMs decline when these RGMs are cured at relatively high temperature for a long time.

The influence of equal amplitude high stress repeated loading on the mechanical and deformation characteristics of rubber concrete

The reuse of waste rubber in concrete has become one of the focuses of environmentalists and researchers in recent years. Rubber concrete pavement is often deformed and damaged by the repeated loading of vehicles. In this paper, a series of experiments are carried out on the deformation of rubber concrete (RC) during equal amplitude repeated loading. It is discussed that the effect of rubber particle size (0.85 mm, 1–3 mm and 3–6 mm) and content (0%, 5%, 10%, 15% and 20%) of RC on the uniaxial mechanical properties and the total strain, elastic strain and plastic strain during repeated loading. The results show that with the increase of rubber content and particle size, the compressive strength and elastic modulus of concrete decrease. After 50 times of repeated loading, the decrease of compressive strength of RC is generally higher than that of NC, but The decrease in elastic modulus is lower than that of NC, which shows that the addition of rubber can slow down the loss of elastic modulus, and the decrease of elastic modulus first decreases and then increases with the increase of particle size and content. During repeated loading, the curves of total strain, elastic strain and plastic strain of RC are significantly higher than those of NC, which indicates that RC has larger deformation and elasticity, but the relative strain range is smaller than NC, showing better stability. The mechanical properties of each group of concrete are evaluated by the analysis of efficiency coefficient, the scoring order of each group is RCA-1 > RCA-2 > RCB-2 > RCA-4 > RCA-3 > RCC-2 > NC. The results show that the best content of rubber is 5%, and the best particle size is 0.85 mm.

Mechanical Properties, Permeability, and Freeze–Thaw Resistance of Pervious Concrete Modified by Waste Crumb Rubbers

Due to the negative effects that derive from large impervious surfaces in urban areas, pervious concrete has been developed, and has become an environmentally friendly pavement material. As a porous and permeable material, pervious concrete presents an overwhelming advantage in solving urban problems, such as flooding, groundwater decline, urban heat island phenomena, etc. Waste crumb rubber has been verified as a feasible modifier for pavement material. The objective of this paper is to explore the effects of rubber particle size and incorporation level on the permeability, mechanical properties, and freeze–thaw resistance of pervious concrete. Two kinds of rubbers (fine and coarse) with four incorporation levels (2%, 4%, 6%, and 8%) are used in the experiment. Permeability, compressive strength, flexural strength, flexural strain, and freeze–thaw resistance are tested. The results indicate that the addition of rubber slightly decreases strength and permeability, but significantly enhances ductility and freeze-thaw resistance. Fine crumb rubber with a suitable incorporation level could remarkably improve the ductility and freeze–thaw resistance of pervious concrete without sacrificing excessively strength and permeability.

Properties of ABS/PMMA Binary Blend and ABS/PMMA/MBS Ternary Blend

An analysis was performed on the effects of rubber particle size on the mechanical and optical properties of the acrylonitrile-butadiene-styrene (ABS)/poly(methyl methacrylate) (PMMA) blend and the ABS/PMMA/methacrylate-butadiene-styrene (MBS) blend. This work found that when the particle size is 0.22-0.23 μm, the impact strength value of the ABS/PMMA blend is at its maximum and is the same as that of the ABS/PMMA/MBS blend. The optimum particle size is effective in toughening because it can trigger the shear yielding mechanism of the matrix. The miscibility and surface glossiness of the blends with 0.22 μm particle size were also much better than those of the blends with other particle sizes. This work provides new insights into the synergistic roles of rubber particle size and core-shell modifier in the toughening of ABS/PMMA blend with good impact toughness and high surface glossiness.

Rubber particle size and type effects on scratch behavior of styrenic-based copolymers

Effects of rubber particle size and type on scratch performance were investigated using two types of styrenic copolymers: acrylonitrile styrene acrylate (ASA) and acrylonitrile butadiene styrene (ABS). ASAs with rubber particle sizes of 100 nm and 1 μm, respectively, and ABS with rubber particle size of 100 nm were examined. Linearly increasing normal load scratch tests were performed according to the ASTM D7027/ISO 19252 standard. A noticeable drop in scratch resistance is found in ASA with 100 nm rubber particles when compared to ASA containing 1 μm rubber particles. ABS is observed to exhibit a higher scratch resistance when compared to ASA with comparable rubber particle size. Detailed deformation and damage mechanisms have been investigated to explain the observed differences in scratch performance of the model systems. Implication of the present findings for design of scratch resistant polymers is discussed.

Notched impact behaviour of polymer blends: Part 2: Dependence of critical particle size on rubber particle volume fraction

The stress-field model introduced in Part 1 is used to analyse the effects of rubber particle size D and volume fraction ϕ on impact behaviour. The model is refined by including energy released from the matrix during rubber particle cavitation, and interactions between cavitated rubber particles, porous shear bands, and crazes, in the later stages of energy absorption. The analysis shows that with increasing ϕ, critical stresses for rubber particle cavitation increase slightly, while yield stresses and craze formation stresses fall substantially, and craze stability increases. Particle morphology and particle–matrix adhesion also affect the locations of the brittle-ductile (BD) transition, which is caused by cavitation resistance in very small particles, and the ductile-brittle (DB) transition, which is due essentially to failure of crazes initiated from larger particles. Comparisons of model predictions with Izod data provide further insight into the ways in which large porous plastic zones develop ahead of notch tips.

Toughening of polyvinylchloride by methyl methacrylate–butadiene–styrene core–shell rubber particles: Influence of rubber particle size

AbstractAn analysis was made on the effects of rubber particle size on the mechanical properties and deformation mechanisms of transparent polyvinyl chloride (PVC) blends containing core–shell methyl methacrylate–butadiene–styrene (MBS) impact modifiers. The critical interparticle distance was found not to be the criterion for the brittle‐ductile transition in the blends. In tensile tests, the blends with larger (100–280 nm) rubber particles exhibited intense stress‐whitening, while one blend with small (83 nm) rubber particles showed only slight stress‐whitening. These differences were due to an increase in resistance to cavitation with decreasing rubber particle size. Transmission electron microscopy studies on blends with a bimodal distribution of particle sizes showed that in the whitened zone of Izod specimens the larger rubber particles cavitated and expanded on yielding, while the smaller particles remained intact. However, Izod test results showed that small MBS rubber particles can toughen the PVC matrix very effectively, especially at low temperatures and at low rubber concentrations. The deformation mechanisms responsible for these effects were discussed. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers

Effect of rubber particle size on the impact tensile fracture behavior of MBS resin with a bimodal particle size distribution

We performed impact tensile fracture experiments on methylmethacrylate–butadiene–styrene (MBS) resin with small and large particles in a bimodal size distribution, and examined the effects of particle size on fracture behavior by fixing the total rubber content (28 wt%) and the small particle size (about 140 nm), and varying the size of large particles (about 490 nm or 670 nm). Dynamic load P′ and displacement δ′ of single-edge-cracked specimens were measured using a Piezo sensor and a high-speed extensometer, respectively. A P′−δ′ diagram was used to determine external work Uex applied to the specimen, elastic energy Ee stored in the specimen, and fracture energy Ef for creating a new fracture surface As. Energy release rate was then estimated using Gf = Ef/As. Values of Gf were correlated with fracture loads and mean crack velocity vm determined from load and time relationships. We then examined the effect of particle size on Gf and vm, and results indicated that particle size plays an important role in changing the values of Gf and vm.

Effect of Rubber Particle Size on Impact Tensile Fracture Behavior of MBS Resin

The single-edge-cracked specimens of MBS resin with two different sizes of rubber particles were fractured under impact tensile loading. The dynamic load and displacement were measured using a piezo sensor and a high-speed extensometer, respectively. The load and displacement diagram, i.e. the external work Uex applied to the specimen was used to determine the elastic energy Ee and the fracture energy Ef for creating a new fracture surface As. Energy release rate was then estimated using Gf = Ef/As. The values of Gf were correlated with the fracture loads and the mean crack velocities determined from the load and time relationships. The effect of the particle size on the impact tensile fracture behavior was then examined. The results showed that the particle size plays an important role in changing the impact fracture behavior of MBS resin.

Impact Behavior Analysis of PC/ABS (50/50) Blends

Impact behavior of simply-supported circular thin plates made of PC/ABS (50/50) blends tested at room temperature by use of instrumented drop weight impact apparatus under different speeds: 2, 3, and 4m/sec has been studied. The blends have 10wt% content of rubber with rubber particle diameter of 270nm and of 150-170nm distributed in ABS. Features of the target are viewed to describe definite alteration of the plates induced by a hemispherical tip-ended cylindrical impactor and effect of rubber particle size distributed in the blends. It was found that the blends with a rubber particle diameter of 150-170nm were not in shattering and exhibited a unique crack shape at speed of 3m/sec. Simulation of the impact test was also performed using dynamic explicit finite element code of MSC. Dytran. In the simulation, the material was assumed isotropic and mass served as a rigid surface and an available material model in the finite element system, called piecewise linear plasticity, referring to a yield model of the von Mises was applied in the simulation for describing the large strain, non-linear behavior of the polymeric materials. Maximum plastic strain failure criterion was then used to simulate the impact failure. Contact between the impactor and the plate was applied and friction coefficient µ between the impactor and the plate was neglected. In order to study effect of friction coefficient value, additional simulation of the impact test has also been performed using µ = 0.3. Impact force-time histories of the blends obtained from the simulation were then verified to the impact test results and pointed out an evaluation of the use of the finite element analysis for predicting behavior of the blends under the impact loading.

Effect of rubber particle size and rubber type on the mechanical properties of glass fiber reinforced, rubber-toughened nylon 6

The effects of rubber type and particle size on the mechanical properties of glass fiber reinforced blends of nylon 6 and EPR/EPR- gMA or SEBS/SEBS- g-MA were investigated; rubber particle size in the two systems could be controlled by varying the ratio of EPR to EPR- g-MA or SEBS to SEBS- g-MA. Unreinforced materials with the highest levels of toughness did not necessarily lead to the highest fracture energy when reinforced with 15 wt% glass fibers. Materials toughened with SEBS/SEBS- gMA, which are tougher in the absence of glass fibers had lower fracture energies when 15 wt% glass fibers are present. In general, smaller rubber particles led to higher fracture energies. Fracture analysis according to a modified essential work of fracture analysis reveals that SEBS/SEBS- g-MA have high values of the dissipative energy density, u d, in the absence of glass fibers. When 15 wt% glass fibers are added, u d is essentially zero for all the materials tested. The limiting specific fracture energy, u 0, on the other hand, was higher for both unreinforced and glass fiber reinforced EPR/EPR- g-MA toughened blends than for SEBS/SEBS- g-MA based materials. Transmission electron microscopy observations of fractured specimens indicate that glass fibers decrease the size of the damage zone of rubber toughened nylon 6. Shear yielding was seen in fractured specimens of reinforced nylon 6 blends containing either SEBS/SEBS- g-MA or EPR- g-MA, but the size of this shear yielded zone was larger for EPR/EPR- g-MA. In addition, EPR/EPR- g-MA based materials displayed craze-like deformations, while SEBS- g-MA materials did not exhibit this deformation process.

Effects of interfacial adhesion on the rubber toughening of poly(vinyl chloride) Part 2. Low-speed tensile tests

The influence of interfacial adhesion on the tensile properties, including toughness, of poly(vinyl chloride) (PVC)–nitrile rubber (NBR) blends with the morphology of well-dispersed rubber particles has been investigated using two types of blends. The first type, which contains NBR26 (NBR with 26wt% acrylonitrile (AN)), has a higher interfacial adhesion strength than the second type that contains NBR18. The secant modulus and yield stress of the blends were found to be independent of interfacial adhesion. On the other hand, the elongation-at-break and toughness (defined as the area under the stress–strain curve to break) depend strongly on the interfacial strength. The effects of rubber particle size, size distribution and rubber volume fraction on the tensile properties have been combined into the effect of a single morphological parameter, the matrix ligament thickness T. Both the elongation-at-break and toughness increase as T decreases. At T<0.06μm the blends with stronger interfacial adhesion (PVC–NBR26) have much higher elongation-at-break and toughness. Stress whitening was observed in all deformed PVC–NBR18 blends. For PVC–NBR26 blends, however, stress whitening occurred only at T>0.06μm. Transmission electron microscopy studies revealed that debonding at the PVC–NBR interface is the sole microvoiding mechanism that causes stress whitening.

437 耐衝撃性ポリスチレンの力学的性質に及ぼすゴム粒子径とひずみ速度の影響

437 耐衝撃性ポリスチレンの力学的性質に及ぼすゴム粒子径とひずみ速度の影響

Effect of Rubber Particle Size and Graft Ratio on the Morphology and Tensile Properties of ABS Resins

Tensile properties and the phase morphologies of ABS resins with various rubber particle sizes and graft ratios of SAN are examined. Large rubber particles disperse well in ABS resins irrespective of the graft ratio. On the other hand, the graft ratio affects the dispersion state of the small rubber particle, particles with high graft ratio disperse well and those with low graft ratio tend to coalesce into large aggregates. These differences of the morphology strongly alter the deformation mechanism, such as craze formation and cavitation in the rubber particles. The effects of mixing of ABS resins with various graft ratio and particle size on the mechanical properties and phase morphology are also discussed.

Toughening of SAN with acrylic core-shell rubber particles: particle size effect or cross-link density?

The effect of rubber particle size on fracture toughness and tensile properties have been investigated using styrene-acrylonitrile as a matrix. Pre-formed particles with poly(butyl-acrylate) core and a poly(methylmethacrylate) shell, ranging from 0.1 to 0.6 μm in diameter, were used as a toughening agent. The morphology was checked by means of transmission electron microscopy. The test methods involved an un-notched uniaxial tensile test, notched Izod impact and notched tensile testing. The experiments were carried out with varying deformation rates and temperatures. N.m.r. experiments were used to measure network densities in the rubber core of the various particles. Uniaxial tensile tests showed that elastic modulus and yield stress of the blends were independent of particle size and network density of the rubber core. There were, however, some differences in cavitation resistance caused by the differences in network density. Easily cavitating particles produced higher toughness in notched Izod impact and notched tensile test but a clear relation with particle size could not be established for the range studied. The brittle-tough transition temperatures were much higher than for materials based on poly(butadiene) core-shell rubbers. It is suggested that the mechanical properties of the rubber particle core are the key to the toughening efficiency. It was found that high toughness could only be achieved if the particles had a low cross-link density (and a corresponding low modulus and low cavitation resistance).

The effect of rubber particle size on toughening behaviour of rubber-modified poly(methyl methacrylate) with different test methods

In order to study the effect of particle size on the toughening behaviour of rubber-toughened poly(methyl methacrylate) (PMMA), a systematic model study has been carried out using core-shell type particles, made up of a poly( n-butyl acrylate) (PBA) core and a PMMA outer shell. Two different fracture tests, i.e. a three-point bending test for the evaluation of the fracture toughness ( K IC) and an impact test were employed to study the toughening behaviour. In the case of the impact test, maximum impact strength was obtained for rubber particles with a 0.25 μm diameter regardless of the rubber phase contents, and only a modest improvement of the impact strength was obtained for blends containing 0.15 or 2 μm particles. For the three-point bending test, in contrast, even large particles such as the 2 μm particles provided a significant enhancement in the fracture toughness. The difference in the toughening behaviour due to particle size may be attributed to the test method dependence associated with a change in the deformation mechanism. In the three-point bending test, the deformation mechanism was found to be multiple crazing, whereas in the impact test, the shear yielding induced by cavitation of the rubber particles is predominant.

Effect of rubber particle-plastic zone interactions on fatigue crack propagation behaviour of rubber-modified epoxy polymers

The purpose of this letter is to report a novel observation on the effect of rubber particle-plastic zone interactions on the transition point in the fatigue crack propagation (FCP) behaviour of rubber-modified epoxy polymers. This observation provides useful information relevant to the modelling of FCP behaviour of rubber-modified thermoset polymers. The findings reported here are the preliminary results from more detailed studies on the effect of rubber particle size and volume fraction on the FCP resistance of rubber-modified epoxy polymers [1]. McGarry and co-workers [2, 3] were among the first to show that the poor fracture resistance of epoxy polymers could be enhanced by the incorporation of a dispersed rubbery phase. Since their initial investigations, several studies [4-10] have provided a detailed description of the deformation micromechanisms responsible for the increase in fracture toughness of rubber-modified epoxy polymers. The most commonly observed among these mechanisms, as shown in Fig. 1, include: (i) localized shear yielding, which refers to shear banding in the epoxy matrix that occurs between the rubber particles; (ii) hole or plastic void growth in the epoxy matrix, which is initiated by cavitation or debonding of the rubber particles; and (iii) rubber particle bridging behind the crack tip. Despite numerous experimental investigations on the fracture mechanisms in rubber-toughened epoxy polymers and some success in modelling the fracture behaviour of these materials under static loading conditions [9, 11], very little is known about cracktip shielding mechanisms in rubber-modified epoxies under cyclic loading conditions. Furthermore, no attempt has been made to model the FCP behaviour