Addition Of Styrene Butadiene Rubber Research Articles

Multi-Criteria Optimization of SBR-Modified Mortar Incorporating Polyethylene Terephthalate Waste

Thermosetting post-consumer plastics like polyethylene terephthalate (PET) raise serious recycling challenges, leading frequently to disposal through incineration or landfilling. This study assesses the feasibility of cementitious materials containing PET additions including the influence of cement content, water-to-cement ratio (w/c), styrene-butadiene rubber (SBR) polymer additions, and PET volume on the fresh and hardened properties. The mixture proportioning followed the Taguchi methodology, which entailed the utilization of four factors, each possessing three different levels to create an L9 orthogonal matrix. The assessment included diverse performance indicators such as flow, compressive strength, flexural strength, bond strength, water absorption, and resistance to carbonation. Test results revealed that the incorporation of SBR and PET degraded the compressive strength, albeit this can be restored by increasing the cement content and/or reducing w/c. The addition of SBR significantly improved the flexural and bond strengths yet curtailed the water absorption and resistance to carbonation due to increased closed porosity that facilitated the transport properties. The multi-criteria optimization approach (TOPSIS) indicated that superior performance can be achieved using a cement content of 525kg/m3, w/c of 0.55, SBR of 3.5%, and PET incorporation of 4.5%. These parameters were subsequently employed in the development of multivariate regression models, allowing for the prediction of fresh and hardened properties in SBR-PET mortar.

Study on the properties and microstructure of polymer modified waste printed circuit board cement-based materials

Waste printed circuit boards (WPCB) are solid waste, and the current disposal of WPCB in landfills has raised environmental concern. Existing studies used ground WPCB as a replacement of fine aggregate in cement-based materials, but the performances of those materials were notably decreased. This paper aims to improve the performance of WPCB-bearing cementitious materials using styrene butadiene rubber (SBR) latex and chloroprene rubber (CR) latex. For this purpose, cement-based materials with ground WPCB as fine aggregates were prepared, and the effects of SBR latex and CR latex on the mechanical properties of WPCB-bearing samples with varying dosages were studied. The influence mechanism was studied using SEM, hydration heat, XRD, and FTIR tests. The results showed that the incorporation of ground WPCB tends to significantly reduce the compressive strength of cement-based materials, while the addition of SBR and CR latex can prevent the strength loss. For instance, with the optimal dosage of 5 % for SBR latex or 7.5 % for CR, the 28-d compressive strength of the latex-modified sample was 42.6 MPa and 45.3 MPa, which was 26.78 % and 34.82 % higher than that of the unmodified samples. Through microstructure analysis, it was found that the incorporation of WPCB had a negative impact on the densification of cement-based materials. SBR latex and CR latex promoted the hydration reaction and formed continuous film products inside the structure, which improved the bonding performance of WPCB cement-based materials.

Combustion characteristics of waste styrene–butadiene rubber oil derived from thermal pyrolysis process: experiment and numerical simulation

Owing to the similar carbon range in components, the pyrolytic oil derived from waste styrene–butadiene rubber (SBR) is preferred in aviation, for achieving waste-to-energy and fly net zero missions. The present study investigated the combustion and emission characteristics of SBR using a constant volume combustion chamber (CVCC) spray at 673–873 K initial temperature (Tini), 10 and 15 bar initial pressure (Pini), and 0.5 equivalence ratio (φ). SBR combustion properties were benchmarked with conventional jet propellant 5 (JP-5), and JP-5 and SBR were blended at a 50% volume ratio (JP-5-SBR-50). SBR has a shorter ignition delay (ID) and combustion delay (CD) at 15 bar Pini, compared to 10 bar. SBR exhibits negative temperature coefficient (NTC) behavior starting from Tini = 773–823 K, which was more significant at 10 bar. In the NTC region, at Tini = 723 and 823 K, the ID nearly has a 3-fold variation between 10 and 15 bar, and CD has 4- and 1.7-fold variations at Tini = 723 and 823 K, respectively. Finally, τ has a 3- and 1.5-fold variation at Tini = 723 and 823 K. JP-5 has a shorter ID and CD, followed by JP-5-SBR-50 and SBR. At Tini = 673 K, the addition of JP-5 to SBR significantly shortened ID and CD by nearly 24% and 17.5%. JP-5 has higher CO2, thermal NOx, and unburned HC emissions, whereas those were reduced with SBR addition to JP-5. Moreover, CO emissions at the SBR NTC region (773–823 K) gradually increased more than at any other tested Tini. Meanwhile, the measured ID periods and NTC characteristics for SBR were replicated using a reduced mechanism of 106 species and 2,162 reactions. The reduced mechanism also predicted the measured SBR inhibition effect on the ID periods for JP-5.

The Mechanical Properties of Jute/PLA Composites Combining Nano Polymerized Styrene Butadiene Rubber Modified by Coupling Agents

ABSTRACT The jute/polylactic acid (PLA) composite material has been widely concerned in the field of composite materials because of its green, degradable and renewable properties, but its low mechanical properties limit the application field. In order to improve the mechanical properties of jute/PLA composites, styrene butadiene rubber (SBR) particles modified by different silane coupling agents were introduced into PLA matrix, and jute/PLA composites were prepared by solution casting and molding method. The changes in the mechanical properties of the jute/PLA composite were studied, and the toughening mechanism of the jute/PLA composite was analyzed. The results show that SBR particles can induce the crystallization of the PLA matrix, and the coupling agent plays a promoting role. The addition of SBR improves the bending and stretching of the jute/PLA composite. The silane coupling agent KH560 has the best modification effect on SBR particles. When the mass fraction of KH560-SBR particles in the composite is 1.0%, its bending strength and modulus achieve the highest, which are respectively 247.04% and 773.91% higher than the control group. When the mass fraction of KH560-SBR particles added in the composite is 2.0%, its tensile strength and modulus are the largest, 517.91% and 472.00% higher than the control group.

(Digital Presentation) Water-Soluble Binders That Enhance Electrochemical Sodium-Ion Storage Properties of NaTi2(PO4)3 Nanoparticle Anodes

Sodium ion batteries (SIBs) have been considered as one of the most promising alternative to conventional lithium-ion batteries (LIBs) for next generation energy storage systems.1 , 2 In terms of anodes, commercial graphite only delivers a sodium-ion storage capacity of 31 mAh g−1.3 The polyanionic-type NaTi2(PO4)3 material is an attractive anode because of the crystal structure of a Na-super-ionic conductor (NASICON), high theoretical capacity, safety characterization and ‘zero-stress’ framework upon sodiation/desodiation.4 , 5 The primary role played by the binder is to link different types of small particles together and to ensure the active material adheres to the current collector, which has an important contribution to the electrical and mechanical behaviour of the electrode.6 , 7 Poly(vinylidene fluoride) (PVDF) is a common organic binder using N-methyl-2-pyrrolidone (NMP) as solvents. Sodium carboxymethyl cellulose (CMC) has been considered as an effective and green water-soluble binders. Styrene butadiene rubber (SBR) typically serves as an elastomer in water-soluble CMC binders and further increases binding force, adhesion, heat resistance, and flexibility of an electrode. The role of different binders on the structural/chemical stability of NaTi2(PO4)3 anode in SIBs has rarely been studied.Here, we synthesized NaTi2(PO4)3 nanoparticles using the hydrothermal method and explore the effects and influence of PVDF, CMC and CMC-SBR binders on the sodium-ion storage performance of NaTi2(PO4)3 anodes. Compared to traditional organic PVDF binder, water-soluble binders improved the cycling stability by increasing adhesion, flexibility, and mechanical properties between the active materials, conductive addictive and current collector. Notably, water-soluble binders show an important effect on the sodium storage mechanism of NaTi2(PO4)3 nanoparticles. The addition of SBR in the water-soluble binders further enhances the active materials areal specific capacity because of its better adhesion ability, reducing the overall quantity of binder polymer required for the electrode. This novel exploration of the effective combination of water-soluble CMC and SBR binders for NaTi2(PO4)3 anodes in SIBs not only provides an opportunity to enhance their electrochemical sodium storage properties, but may enables their practical application in high areal energy density sodium ion batteries in the future. References (1) Nayak, P. K.; Yang, L.; Brehm, W.; Adelhelm, P.: From Lithium-Ion to Sodium-Ion Batteries: Advantages, Challenges, and Surprises. Angew. Chem. Int. Ed. 2018, 57, 102-120.(2) Kim, S.-W.; Seo, D.-H.; Ma, X.; Ceder, G.; Kang, K.: Electrode Materials for Rechargeable Sodium-Ion Batteries: Potential Alternatives to Current Lithium-Ion Batteries. Adv. Energy Mater. 2012, 2, 710-721.(3) Doeff, M. M.; Ma, Y.; Visco, S. J.; De Jonghe, L. C.: Electrochemical insertion of sodium into carbon. J. Electrochem. Soc. 1993, 140, L169-L170.(4) Delmas, C.; Cherkaoui, F.; Nadiri, A.; Hagenmuller, P.: A nasicon-type phase as intercalation electrode: NaTi2(PO4)3. Mater. Res. Bull. 1987, 22, 631-639.(5) Chen, S.; Wu, C.; Shen, L.; Zhu, C.; Huang, Y.; Xi, K.; Maier, J.; Yu, Y.: Challenges and Perspectives for NASICON-Type Electrode Materials for Advanced Sodium-Ion Batteries. Adv. Mater. 2017, 29, 1700431.(6) Chen, H.; Ling, M.; Hencz, L.; Ling, H. Y.; Li, G.; Lin, Z.; Liu, G.; Zhang, S.: Exploring Chemical, Mechanical, and Electrical Functionalities of Binders for Advanced Energy-Storage Devices. Chem. Rev. 2018, 118, 8936-8982.(7) Bommier, C.; Ji, X.: Electrolytes, SEI Formation, and Binders: A Review of Nonelectrode Factors for Sodium-Ion Battery Anodes. Small 2018, 14, 1703576. Figure 1 (a) SEM image and (b) HRTEM image of NaTi2(PO4)3 nanoparticles with quasi-cubic architecture and hollow structure. (c) XRD analysis of the synthesized nanoparticles. (d) Specific capacity versus rate data using chronoamperometry (CA) method for NaTi2(PO4)3 nanoparticles anode of different binders. (Inset) Corresponding digital photos for NTP electrodes with different binders. (e) The first cycle in the cyclic voltammetric curve at a scan rate of 0.1 mV s-1 for NaTi2(PO4)3 nanoparticles anode. (f) Galvanostatic discharging and charging cycling stability at 0.2 C (1C = 133 mA g-1) for the NaTi2(PO4)3 nanoparticle anode with different binders. Figure 1

Improving Fundamental Understanding of Si-Based Anodes Using Carboxymethyl Cellulose (CMC) and Styrene-Butadiene Rubber (SBR) Binder for High Energy Lithium Ion Battery Applications

With increasing demand of high energy density lithium ion batteries, silicon (Si) based anodes are an obvious substitute of graphite based systems due to their high capacity. However, large volume changes of Si during lithiation and delithiation processes causes pulverization of silicon particles. The resulting reduction in electrical continuity and solid electrolyte interphase (SEI) growth within the anode leads to a fast depletion of lithium reservoirs and an accelerates battery failure. High energy lithium ion battery applications such as electrical vehicles and electronic devices require high capacity retention over extended cycling, so improving performance of Si-based anodes is a critical need for many applications.Commonly, a combination of sodium carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR) is used as a binder for waterborne Si anode slurries. In these systems, carboxyl (-COOH) groups on CMC form chemical bonding with hydroxyl (-OH) groups on Si active material surface and SBR addition provides enhanced flexibility in the anode layer. Several reports on electrode integrity improvement through adhesion promoters, increased crosslinking, different binding groups, etc. are available in the literature. Delving deeper into the weak mechanical integrity of Si based anodes, and understanding the parameters influencing the fabrication process and subsequent properties, is important. This presentation will focus on several variations in Si based anode slurries and electrodes using CMC-SBR binders. Physical, mechanical, and electrochemical properties are extensively studied as a function of these parameters and will be discussed.

Organic Solvent Free Process to Fabricate High Performance Silicon/Graphite Composite Anode

Cycling stability is a key challenge for application of silicon (Si)-based composite anodes as the severe volume fluctuation of Si readily leads to fast capacity fading. The binder is a crucial component of the composite electrodes. Although only occupying a small amount of the total composite mass, the binder has major impact on the long-term electrochemical performance of Si-based anodes. In recent years, water-based binders including styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) have attracted wide research interest as eco-friendly and low-cost alternatives for the conventional poly(vinylidene difluoride) (PVDF) binder in Si anodes. In this study, Si-based composite anodes are fabricated by simple solid mixing of the active materials with subsequent addition of SBR and CMC binders. This approach bypasses the use of toxic and expansive organic solvents. The factors of binder, silicon, and graphite materials have been systematically investigated. It is found that the retained capacities of the anodes are more than 440 mAh/g after 400 cycles. These results indicate that organic solvent free process is a facile strategy for producing high performance silicon/graphite composite anodes.

Modification Mechanism of Asphalt Modified with Rock Asphalt and Styrene-Butadiene Rubber (SBR)

High-performance asphalt binder plays an important role in the durable asphalt pavement. Asphalt modified by rock asphalt (RA) is one of the high-performance modified asphalt materials. It was used in road engineering as a relatively environmentally friendly material, because rock asphalt takes some advantages of large reserves, easy treatment, and efficient modification. Moreover, the main component of rock asphalt is bitumen, which enables it to substitute part of the binder used in asphalt mixtures. On the other hand, the negative low-temperature performance of RA modified asphalt impeded its application in cold regions. The object of this paper is to improve the low-temperature performance of RA modified asphalt by compound modified with styrene-butadiene rubber (SBR). The 70-penetration grade binder and the RA modified asphalt with 15% RA by weight were applied as the base binder. Five types of RA-SBR modified asphalt were prepared, and the content of SBR was 2%, 4%, 5%, 6% and 8% by weight of BRA modified binder. The Fourier transform infrared spectroscopy (FTIR) tests were utilized to illustrate the reasons for the poor low-temperature performance of BRA modified asphalt and reveal the compound modification mechanism of BRA-SBR modified asphalt. The Brookfield viscosity test, dynamic shear rheometer test, and bending beam rheometer test were adopted to reveal the variation patterns of rheological behavior and low-temperature performance with mass contents of SBR. The test results indicated that the worse of low-temperature performance was caused by the increase of asphaltene content and the stress concentration due to ash in RA modified asphalt. And the compound modification is a physical process. The addition of SBR has improved the low-temperature performance of RA modified asphalt dramatically. And based on the rheological behaviors and low-temperature performance of RA-SBR compound modified asphalt, the optimum content of SBR was determined, which is about 4%∼5%.

Combined effects of styrene–butadiene rubber (SBR) latex and recycled aggregates on compressive strength of concrete

Recycled Aggregates (RA) produced from the construction and demolition (C&D) waste can be utilized along with Natural Aggregates (NA) to optimize the concrete’s compressive strength (CS). We evaluated the combined effects of Recycled Aggregates Concrete (RAC) and Styrene–Butadiene Rubber (SBR) Latex on the concrete’s workability and compressive strengths. 72 concrete specimens of 4 groups with respect to the aggregate replacement levels, i.e., 100% NA, 50% NA + 50% RA, 25% NA + 75% RA and 100% RA and 3 groups with respect to SBR Latex dosages i.e., 0%, 1% and 2% were tested. Standard procedure ASTM C-192 was adopted to prepare the concrete test specimens having cement, sand, and aggregates. Variations in compressive strength with varying percentages of RA and SBR Latex at 7, 14 and 28 days were evaluated. The percentages of RA for better strength were found with 50% NA + 50% RA with 2% addition of SBR. Maximum compressive strength was achieved for 50% replacement levels of RA with NA for all SBR Latex addition levels of 1% and 2%, but it was highest at 2% SBR dosage. The overall trend of the compressive strength variation was due to the increasing percentages of recycled aggregates and SBR Latex. 50% or lower replacement levels of RA along with 2% SBR addition is suggested. The SBR Latex induced positive effects on concrete’s compressive strength, as it increased the concrete strength with its increasing percentages. The role of SBR Latex is affirmed in compensating the reductions in CS, due to an increasing percentage of RAs.

Effect of Admixtures on Mechanical Properties of Cementitious Mortar

In the current study, the primary focus is to investigate the effect of Styrene Butadiene Rubber (SBR), silica fume and fly ash on compressive and flexure strengths of cementitious mortar. Three types of specimens are prepared; the first series comprises of control specimen; the second one consists of the mortar’s specimen modified with SBR and the third one consists of the mortar’s specimen modified with SBR in a combination of fly ash and silica fumes. Mortar samples are cast in the weight ratio of 1:2.75 (cement: sand). The SBR is added at a rate of 20% of the mass of cement. The water to cement ratio (W/C) is kept at 0.5 for control specimens and the quantity of mixing water in SBR-containing samples is reduced by the same amount as the SBR is added: The adjustment is meant to obtain same consistency for all the specimens. 20% fly ash and 2.5% silica fume are added to the mortar as replacement of cement. Compressive and flexure tests are carried out according to ASTM standards. Moreover, SEM is also performed on samples at the age of 28 days. Studies reveal that SBR and SCMs reduce the mechanical strength of the mortars. SEM and EDS studies show that SBR hinders the formation of albite, whereas silica content from silica fumes and fly ash converts CaCO3 to Wollastonite (a white loose powder), which is responsible for the reduction of mechanical strength. The study also confirms that the addition of SBR in place of water hinders the formation of primary and secondary hydration products. Doi: 10.28991/cej-2020-03091610 Full Text: PDF

Behavior of oil well cement slurry systems aged in CO2-saturated water under high pressure and temperature

This paper aims at studying the effect of the exposure of hardened cement slurries, intended for oil wells, to carbon dioxide (CO2) in the state of water saturation. Four different systems of cement slurry with water/solid (w/s) ratio of 0.33 ± 0.01 and density of 1.98 ± 0.06 g cm−3 were design. The first cementitious system was a reference cement slurry (PR) commonly used for the cementation of wells. The other systems were obtained modifying the reference slurry with the addition of styrene-butadiene rubber (PRSBR), silica fume (PRSF) or crystalline silica (PRCS). The slurries were optimized in order to fulfill the rheological, physical and mechanical requirements to the cementation of oil fields. Cement slurries samples were aged in CO2-saturated water at 65 °C and 21 MPa pressure, for 30, 60 and 90 days. The degradation of the slurries was studied by thermogravimetric analysis. The carbonation rate with time and the carbonation profile along the diameter of the cylindrical samples were evaluated. Gas permeability and total porosity tests were carried out before and after aging also were determined to complement the analysis. From the results obtained, it was observed that the PR and PRSF mixtures presented the smallest amounts of calcium carbonate, especially in the internal layers of the sample. This happens due to the low permeability and total porosity of these mixtures that presented a high content of hydration products, including C–S–H. The PRSBR and PRCS mixtures presented high porosity and permeability and consequently higher carbonation than the PR mixture for all ages of CO2 exposition evaluated.

Preparation and Properties of Carbon Nanofiber Modified Emulsified Asphalt Based on Ultrasonication and Surfactant and the Impact of SBR and NH4Cl

Carbon nanofiber (CNF) is a nanomaterial with unique mechanical properties, which can improve the properties of composite materials effectively. Types of research focused on the impact of CNF on asphalt, asphalt binder, and mixture. Traditional emulsified asphalt presents a limited performance at both high and low temperature. Meanwhile, emulsified asphalt with better performance is required in engineering. Referring to the research of CNF-asphalt, CNF is considerable to improve the performance of emulsified asphalt. In this study, a preparation method for CNF modified emulsified asphalt with styrene-butadiene rubber (SBR) was proposed. Ultrasonication and surfactant were utilized to disperse the CNFs in water. The optimum dispersion surfactant percentages and ultrasonic energy density to disperse CNFs were determined through ultraviolet-visible spectra (UV-vis spectra). The modified emulsified asphalt was produced using CNFs suspension with SBR as a modifier, and the properties of the residue with different percentages of CNFs were tested. Gel permeation chromatography (GPC) was performed to analyze the molecular size distribution. The results indicated that CNFs improved high-temperature performance of the residue significantly but decreased low-temperature properties. The addition of SBR not only perfected storage stability but also improved low-temperature performance by introducing more small molecules.

Gas products generation mechanism during co-pyrolysis of styrene-butadiene rubber and natural rubber

In this study, reaction molecular dynamics were combined with experiments to gain in-depth understanding of the gaseous pyrolysis products generation mechanism and optimal paths during natural rubber (NR), styrene-butadiene rubber (SBR) and mixed rubbers (NR-SBR) for effective recovery of waste rubber. The results show that the pyrolysis temperature of NR increases gradually with SBR addition. The monomers produced during the initial stage of SBR pyrolysis are mainly 1,3-butadiene and styrene, in which the energy barriers of the formed H and CH2=CH in styrene are higher than those in 1,3-butadiene, and during further pyrolysis the main gas products are H2 and CH4. During co-pyrolysis of NR-SBR, the reaction paths show that increasing H2 yield and decreasing CH4 yield take place easily as SBR content rises. By contrast to pyrolysis of NR, the path of generating CH2=CH in SBR is more difficult while that of CH2=CH abstracting H occurred easily, leading to first enhancement in produced CH2=CH2 followed by a decline. Fixed bed experiments and gas chromatography (GC) analysis identify the main gas products of the three rubbers (NR, SBR, NR-SBR)as H2, CH4 and CH2=CH2 and the change of yield caused by the increase of SBR content are consistent with the simulation results.

EFFECT OF POLYMER/CEMENT RATIO AND CURING REGIME ON POLYMER MODIFIED MORTAR PROPERTIES

ABSTRACT Cement is the most consumed building material in the world. However, cement manufacture is responsible for 5–7% of the world CO2 emissions. In this paper, cement was partially replaced by styrene-butadiene rubber (SBR) polymeric latex in order to reduce cement consumption. Besides, effects of SBR addition on the strength and physical properties of plain mortar exposed to three different curing regimes are presented. Three different curing regimes were applied to the 40 × 40 × 160 mm prismatic mortar specimens: (I): Specimens were cured in water until the test age (CW), (II): after demoulding, specimens were immersed in water for 2 days and kept in ambient temperature until the time of the test (2DWA) and (III) involved 2 days of water curing followed by 1 day in an oven at 50°C and subsequentely placing in ambient temperature until the test time (2W1OA). Results showed that combining 2 days of water curing followed by ambient temperature curing (2DWA) along with 3% SBR polymer content showed good performance in terms of compressive strength, water absorption and void content. Moreover, a good performance in terms of flexural strength was observed by combining 2W1OA curing regime with 2% SBR content. However, the detrimental effect of water curing regime (CW) in terms of compressive and flexural strength was also observed with the increase of SBR ratio.

Fresh and Hardened Properties of Styrene Butadiene Rubber (SBR) Modified Concrete

The durability of concrete has been studied ever since it was first used. Researchers have incorporated several materials to make concrete strong and durable. This research focuses on the infusion of styrene butadiene rubber polymer (SBR) as a partial replacement of cement and studies its effects on fresh and hardened properties of concrete. Samples were prepared using partial replacement of SBR in proportions of 0%, 5%, 10% and 20%. Results showed that the fresh density of concrete decreased with the addition of SBR whereas the trends of workability showed an increase with cement replacement. Compressive strength increased at lower percentage replacements however the flexural and tensile strength increased till 15% SBR addition after which it decreased. The total porosity in terms of water absorption decreased which makes SBR modified concrete feasible for concretes exposed to moist conditions and the decreased porosity would increase its durability against chloride induced corrosion.

Fresh and Hardened Properties of Styrene Butadiene Rubber (SBR) Modified Concrete

The durability of concrete has been studied ever since it was first used. Researchers have incorporated several materials to make concrete strong and durable. This research focuses on the infusion of styrene butadiene rubber polymer (SBR) as a partial replacement of cement and studies its effects on fresh and hardened properties of concrete. Samples were prepared using partial replacement of SBR in proportions of 0%, 5%, 10% and 20%. Results showed that the fresh density of concrete decreased with the addition of SBR whereas the trends of workability showed an increase with cement replacement. Compressive strength increased at lower percentage replacements however the flexural and tensile strength increased till 15% SBR addition after which it decreased. The total porosity in terms of water absorption decreased which makes SBR modified concrete feasible for concretes exposed to moist conditions and the decreased porosity would increase its durability against chloride induced corrosion.

Hybrid Fiber Reinforced Concrete with the Addition of Styrene Butadiene Rubber (SBR) Polymer

Hybrid Fiber Reinforced Concrete with the Addition of Styrene Butadiene Rubber (SBR) Polymer

Improvement of Low-Temperature Performance of Buton Rock Asphalt Composite Modified Asphalt by Adding Styrene-Butadiene Rubber.

To improve the low-temperature performance of the Buton rock asphalt (BRA)-modified asphalt, styrene-butadiene rubber (SBR) was added to it. The BRA-modified asphalt and SBR-BRA composite modified asphalt were prepared by high-speed shearing method. The penetration, softening point, ductility, and Brookfield viscosity of the two kinds of asphalt were measured. The dynamic shear rheometer (DSR) and the beam bending rheometer (BBR) were employed to research the performance of BRA-modified asphalt by adding SBR. The results showed that the pure asphalt in BRA was the main reason to reduce the low-temperature performance of neat asphalt when the content of BRA was 19%. However, the ash in BRA was the main factor to reduce the low-temperature performance when its content was more than 39.8%. When the BRA content was 59.8%, the SBR-BRA composite modified asphalt with SBR contents of 2%, 4%, 6%, and 8%, and it shows that the penetration and ductility of the BRA-modified asphalt are increased by the addition of SBR. The equivalent brittle point was reduced, the stiffness modulus was decreased, and the creep rate was increased. At the same time, the Brookfield viscosity was reduced and the rutting factor was increased. The stiffness modulus of the SBR-BRA composite modified asphalt mixture was increased. That is to say, when SBR was mixed into the BRA-modified asphalt, the low-temperature performance could be remarkably improved based on ensuring high-temperature performance. The low-temperature index of composite modified asphalt was analyzed. It was recommended to apply the equivalent brittle point to evaluate the low-temperature performance of SBR-BRA composite modified asphalt.

Influence of the addition of styrene-butadiene rubber on the dynamic properties of polymer concrete for machine tool applications

In this study, the influence of the addition of styrene-butadiene rubber on the dynamic properties of polymer concrete was investigated. A 10% volume addition of styrene-butadiene rubber granulate with three different grain gradations was used for the tests. The modal study was carried out in the 0 to 2000 Hz frequency range. The response function for a single impulse excitation was tested. The relaxation time after excitation, the modes of natural vibrations and the amplitude of the transfer function values as well as vibration damping ratios were also compared. Finally, conclusions were formulated regarding the application of the styrene-butadiene rubber additive as a material to improve the dynamic properties of polymer concrete. The best results were obtained for a sample made with a 10% styrene-butadiene rubber volume addition with grain sizes from 0.6 to 2 mm. In this case, the biggest decrease of the amplitude of the transfer function value was 76%, while the biggest increase of the damping ratio was 431.5%, in comparison with the clear polymer concrete sample. The worst results were obtained for a sample made with a 10% styrene-butadiene rubber volume addition with grain sizes from 2.5 to 6 mm. In this case, the longest relaxation time of the sample, the increase of the amplitude of the transfer function value and the decrease in the damping coefficient were recorded.

Strength and transport properties of concrete with styrene butadiene rubber latex modified lightweight aggregate

This experimental work aims to explore the effect of adding SBR (styrene-butadiene rubber) polymeric latex in lightweight aggregates and to study their impact on the concrete. Usually, the SBR is used for precast works and repair works which improve mechanical properties and durability of concrete structures. In this paper, SBR modified lightweight aggregate (SLWA) and normal lightweight aggregate (NLWA) without SBR addition were prepared by palletization process and hardened by cold-bonding technique. The cement (20%) as a binder with fly ash (80%) had been used. The compressive strength, water sorptivity, chloride ion permeability and water permeability tests were performed on SBR added lightweight aggregate concrete (SLWAC). Also, their results were compared with normal lightweight aggregate concrete (NLWAC) of similar composition. In addition to that, fly ash (FA) was partially substituted with natural sand (NS) in concrete. SEM images confirmed the refinement in the microstructure of SLWA. Results revealed that SLWAC presented better desirable outcome than NLWAC owing to higher open porosity and lesser strength of the NLWA respectively. Moreover, it was observed that a considerable enhancement in the strength and transport properties of concrete was achieved by the addition of FA as the partial substitution of the NS.