Softening Point Values Research Articles

Sustainable production of WMA with pine gum wax modification

Warm mix asphalt (WMA) (S®-WMA) produced with Sasobit® (S®), a widely used organic admixture, shows a significant increase in softening point value and a decrease in stripping resistance. These two characteristics of S®-WMA are considered as some problems to be solved. Therefore, this study was established to evaluate possible solutions to these two problems through another modification process. In this study, it was investigated whether modifying S®-WMA using a previously unstudied product, pine gum wax (PGW), could be a solution to the problem. In this context, WMA was produced with S® at 1, 2 and 3 in percent by mass of bitumen. As PGW has not been previously used as an additive to modify S®-WMA, it was added within a limit of 1% (by bitumen mass) for initial investigation. Physical and rheological standard tests were performed on each sample to demonstrate the change in properties of S®-WMA produced with 1% PGW compared to S®-WMA. The results indicated that the addition of 1% PGW to S®-WMA resulted in a significant reduction in softening point and an improvement in stripping resistance compared to S®-WMA. Thus, it seems that the use of PGW could be a potential solution for the two mentioned problems. It can also be pointed out that modifying the S®-WMA specimen with PGW without compromising its properties can help in an efficient, economical and environmentally friendly solution. However, due to the use of PGW, more in-depth research is required.

Investigation of Physical and Chemical Properties of Bitumen Modified with Waste Vegetable Oil and Waste Agricultural Ash for Use in Flexible Pavements

The rapid growth of the world population and the rapid diversification of consumption habits due to technological advancements have increased waste production. An investigation of the effects of biomass products, such as waste vegetable oil and waste agricultural ash, on bitumen’s physical and chemical properties was conducted in this study. By recycling biomass products, this study aimed to improve the performance and stability of bituminous hot mixtures, optimize the number of additives, and create more economical designs. Using the Taguchi method, 0%, 2%, 4% by weight of waste vegetable oil and 0%, 3%, and 6% by weight of waste agricultural ash were added to 70/100 penetration pure bitumen with an orthogonal array of L9. For 10, 20, and 30 min, modified bitumen samples were prepared at 170 °C, 180 °C, and 190 °C with a constant mixing speed of 3000 RPM. The samples were tested for penetration, softening point, flash point, rolling thin film oven (RTFOT), FTIR, and Marshall Design stability and flow. Based on the obtained performance statistics, 95% confidence levels were assigned to the predictions. The stability and softening point values decreased as the oil content increased, while flash and penetration values increased. With increasing ash content, stability, flash, and softening point values increased, and penetration values decreased. Compared to oil and ash additives, mixing temperature and time had relatively little effect on the modification process. Overall, the optimum parameter levels were 4% for oil, 0% for ash, 170 °C for temperature, and 10 min for time.

Determination of Mechanical Properties of Fruit Shell Powders Reinforced Wood Plastic Composite (WPC) Materials and Case Study for I-Type Snap-Fit Model

High quality material production has been among the work of many researchers in recent years. These materials, which are obtained mostly by the production of composite materials, enable the production of lighter, more durable and less costly products. Increasing environmental pollution in recent years, protection of natural resources and ensuring recycling have increased the importance of wood plastic composite material production. In this study, wood plastic composite material was obtained by using ABS (Acrylonitrile butadiene styrene) plastic material and six different fruit shell powders (walnut, pistachio, peanut, almond, hazelnut and apricot shell). The mechanical properties of the obtained composite material were determined and its effect on the I type snap-fits was analyzed in ANSYS software. When the resulting composite material's mechanical properties were tested, it was found that the density and tensile strength decreased while the Vicat softening point value and melt flow rate increased. In the analysis performed using the ANSYS software, it was found that the composite I type snap-fit design of the same size can resist 12.6% N less force when the material is subjected to its maximum values when it achieves the elongation at break value.

Evaluation of Asphalt Produced from Waste Tyre and Polyethylene Terephthalate-Based Bitumen with Paraffin Wax as Rejuvenator

During pavement construction and rehabilitation, large amounts of bitumen are often required. As such, the need for material diversification in pavement construction is essential to conserve the non-renewable natural resource deposits. This study assessed the use of Polyethylene Terephthalate (PET) waste and grounded tyre combined in varying proportions with aged bitumen modifier, and wax as a rejuvenator in the production of asphaltic concrete. A 10% polymer replacement level was maintained for all modified mix batches with three distinct proportions: 6%-PET:4%-GWT, 5%-PET:5%-GWT, and 4%PET:6%-GWT. The rejuvenator was added in percentages 1, 2, and 3 by the total mass of modified bitumen mix. Results showed that the penetration values of the modified bitumen mixes with wax fall between bitumen grades 20–60, indicating suitability in warmer climates. Ductility results indicate an increase in ductility upon modification compared to the control mix. The 6%PET/4%GWT samples obtained the highest ductility values (M2 = 23.5 cm, M5 = 12.5 cm, M8 = 22 cm, M11 = 24.25 cm). The highest softening point value (84.5°C) was obtained with M3 (5%PET/5%GWT/0%wax). The inclusion of wax as a rejuvenator led to massive increases in viscosity values compared to both the control mix and the mixes without wax. Flash and fire point results fell within the same range, implying that the modification and rejuvenation did not yield significant impact on the flash and fire point properties. Marshall stability results showed that no modified bitumen batch obtained stability up to the control mix. The highest flow value (5.9 mm) was obtained with the M12 (5%PET/5%GWT/3%wax) mix. This was about 47.45% higher than that of the control mix and 23.7% higher than that of the corresponding mix without wax. The study recommends material diversification as well as dosage variation as essential in the drive towards achieving optimum stability in asphaltic composites.

Optimizing the formulation design and investigating the composite modification mechanism of pyrolysis carbon Black/Polyethylene/Synthetic plant ester composite modified asphalt

Pyrolysis carbon black (PCB) is the surplus product of waste tires after pyrolysis. Polyethylene (PE) is the main component of disposable plastic bags, and synthetic plant ester (SPE) is an environmentally friendly plasticizer that has recently emerged. In this study, the aforementioned three materials were used to prepare an environmentally friendly composite-modified asphalt (CM-A). The optimization of the formulation design of the PCB/PE/SPE additive with asphalt was performed using the response surface mixture-design method, with conventional asphalt performance as the control index. The compound modification mechanism was investigated using modern microscopic testing techniques. The recommended formulations for the additives were BA:PCB:PE:SPE = 0.881:0.081:0.022:0.016 by mass. The resulting CM-A exhibited comparable penetration, ductility, and fatigue properties to base asphalt (BA), with higher high-temperature rutting resistance and softening point values. Microscopic test results revealed that the PCB/PE/SPE was physically blended with asphalt. The plasticizing effect of SPE enhanced the plasticity of PE molecules and significantly improved the compatibility properties of PE and BA. The thermal behavior of CM-A was similar to that of BA but with a slightly higher ash content due to the presence of PCB. The results provide a reference for the industrial production of asphalt modifiers, modification mechanism studies, and a new solution to alleviate environmental pollution and resource waste problems from solid waste accumulation.

Laboratory evaluation of the effect of waste materials on mechanical properties of asphalt binder and mixture containing combined natural binder and waste polymer

The current study's objective is to examine the characteristics of waste polymer-incorporated natural binder modified binders and combinations. Recycling and making use of waste polymers has gained interest as a possible environmentally and financially responsible bitumen modification method. The goal of the current study was to explore the rheological and mechanical characteristics of mixes and bitumens modified with natural binder that contained various amounts of waste polymer. Original bitumen modified with 5%, 10%, and 15% weight of asphalt binder as well as varied amounts of RPW (3%, 5%, and 7% weight), were all employed as samples of bitumen in the study. Several asphalt binder tests such as conventional tests and rheological ones were performed on binder samples. The results showed that adding waste polymer to the natural binder modified binders enhanced their high-performance temperature, as seen by the decreased penetration and increased softening point values. Results revealed that binders containing 5%, 10% and 15% gilsonite have fatigue life at 2.5% strain about 1.06, 9, and 9.8 times higher than original binder, respectively. Results revealed that addition of 5%, 10% and 15% gilsonite leads to decrease the Jnr value by 36%, 87%, and 96%, respectively. While addition of 3%, 5%, and 7% RPW leads to increase the fatigue life by 1.12, 3.75, 5 times higher than 5% gilsonite modified asphalt. Additionally, the binders treated with waste polymers performed better at low temperatures as seen by their decreased stiffness and enhanced fracture resistance. However, a substantial proportion of waste polymer caused both low and high temperature performance to decline. Overall, this study indicates that waste polymer has the ability to enhance the performance characteristics of naturally occurring binder modified binders, but it is important to carefully evaluate the ideal waste polymer percentage in order to obtain the required performance advantages.

High temperature resistant rubber asphalt

Rubber Asphalt is the asphalt with rubber addition. The addition of rubber to asphalt was expected to have higher stiffness and longer durability that can be identified by its properties, that are softening point, penetration and ductility. The 60/70 penetration asphalt has been mixed with 7% rubber. Mixing of rubber with asphalt was quite a challenge. The liquid rubber or solid rubber should be processed through prevulcanization in the asphalt plant. The properties of the rubber asphalt have been investigated in the laboratory of BPJN West Sumatera. Hence, the properties of rubber asphalt have followed the Bina Marga standard for pavement mixture, i.e. the softening point value is >52°C, the ductility is more than 140 cm, and the burning point was above the 310°C. By determined the index penetration of the rubber asphalt that is. Thus, it can be concluded that the 7% rubber asphalt has resulted in the higher resistance to higher temperature binder.

Enhancing Bitumen Properties through Worm Mix Asphalt Additives: A Study on Physical and Rheological Characteristics

This study aimed to determine how various concentrations of warm mix asphalt (WMA) additives can affect the rheological and physical characteristics of asphalt cement. Bitumen was modified by the chemical additive PAWMA® with an addition ratio of (0.2, 0.4, and 0.6), while the organic additives, Sasobit® and Kaowax®, were added at concentrations of (2, 4, and 6%) by the weight of bitumen. Bitumen hardness, softness, temperature susceptibility, viscosity, and elastic behavior have all been measured using a variety of physical and rheological tests, such as the penetration degree, softening point, penetration index, rotational viscosity, and dynamic shear rheology. This study showed that bitumen physical and rheological properties were affected differently according to the type and percentage of the WMA additive employed. The PAWMA additive, for instance, raised the bitumen penetration while Sasobit® and Kaowax® decreased the bitumen penetration degree. The inverse occurred for the softening point values. All WMA additives lowered bitumen viscosity values. Results from a dynamic shear rheometer (DSR) showed that the rutting index value (G*/Sin) rose, indicating improved rutting resistance.

Evaluation of prina for use in asphalt modification

In this study, the usability of prina, which is a biomass waste, in asphalt modification was evaluated by investigating its effects on the physical, rheological, microstructural and chemical characteristics of asphalt binder. For this, modified asphalt binders were obtained by adding prina (wt. 5, 10, 15, 20 %) to pure B160/220 penetration class asphalt. The properties of the pure and modified binder samples were determined by exposure to penetration, ductility, softening point, dynamic shear rheometer, rotational viscometer, bending beam rheometer, scanning electron microscopy, X-ray diffraction, and elemental analysis tests. According to the physical test results, with the addition of 15 % prina, the penetration and ductility values of asphalt binders decreased by 26.4 % and 14.4 %, respectively, and the softening point values increased by 11.3 %. In addition, it was observed that the temperature sensitivity of the binder decreased by 58.2 % at this rate and the penetration class changed to B 100/150. The rheological test results showed that the permanent deformation (rutting) resistance of binders with 15 % prina added in particular increased at 6 °C higher temperatures compared to pure asphalt, and the prina modified binders behaved like a more elastic solid despite hardening. Chemical characterization results showed that prina additive contributed to the increase in the flexibility of modified binders due to its cellulosic and flexible structure. As a result, it is evaluated that prina can be used as a remedial additive in asphalt modification and contribute to the increase of pavement performance, and also that the damage of this waste material to the environment can be eliminated.

To Study the Mixing and Compaction Temperatures of Organophilic Nanoclay Modified Asphalt Binder

Abstract: The use of modified asphalt binders in hot-mix asphalt has steadily increased over the past several decades. Mixing and compaction temperatures of an asphalt binder plays a vital role in the production and placement of asphalt mixes but there are no standards for mixing and compaction temperatures for modified asphalt binder especially with Organophilic nanoclay. In this study the effect of nanoclay modified binder on mixing and compaction temperatures of asphalt mixture was observed using conventional test for asphalt mixture-softening point test, penetration test and rotational viscometer test. Five different percentages i-e 3, 3.5, 4, 4.5 and 5% of Nanoclay (modifier) are selected for three different binders (ARL 60/70, ARL 80/100 & NRL 60/70). Six different samples for each binder are prepared and conventional testing is carried out using standard procedures. With an increase in the percentage of Nanoclay the softening point values and viscosity values increases, similarly the penetration values decrease. The mixing temperature range is 155-165°C and compaction temperature range is 135-145 °C to achieve maximum density in the field

Investigation of rheological properties of asphalt mixtures containing polymer waste.

The objective of this study was to evaluate the rheological performance of rubberised asphalt binder with varying dosages of crumb rubber (CR), and compare these modified materials with unmodified asphalt binder. It is very important to investigate the characterization of chemical structures of the asphalt binder from a closer view for useful modifications of the virgin binder by polymer waste as modifiers. The current research employed a thin layer chromatography technique (TLC) to separate and determine the different fractions in asphalt. Nuclear Magnetic Resonance (NMR) spectroscopy was also used to characterize and confirm the chemical compositions of asphalt and its fractions. Despite of NMR spectra of asphalt is difficult to be interpreted via its structural complexity, but this technique is still able to provide useful data especially with regard to asphaltene fraction. Crumb rubber is a polymer waste which used as modifier of asphalt binder via the economic benefits and improving the rheological properties of modified asphalt binder. The rubberised asphalt binders were produced by blending the virgin asphalt with CR at various contents (3%, 5%, 10%, 15% and 20%). The effects of CR contents on the rheological behaviors of modified asphalt binder have been investigated including: penetration, softening point, ductility. Furthermore, morphological analysis of rubberised asphalt was conducted via scanning electron microscopy (SEM) to assess the effect of CR on the binder morphological structure. Based on results obtained, binder with highest CR content showed improvement in rheological properties of the modified binders in terms of decreasing in penetration, increasing in softening point values and keeping the ductility higher, unlike other CR contents which exhibited poor performance of modified asphalt.

Investigating the preparation and characterization of nano-clay modified asphalts

In order to extend the lifespan of flexible pavements materials, a binder quality requests to be modified. The aim of the present research is to assess the physical features of original and modified asphalts with nanoclay materials. These features including; softening point values, penetration grades, viscosity values, penetration index values, and ductility. Three percentages of nanoclay contents (3, 5, and 7) % by of the asphalt weight were blended by a shear blender set at (4000) rpm., and mixing time set about 45 min. at 140 °C. Physical tests results showed that adding nanoclay material as a modifier was beneficial in enhancing the asphalts features. For example, viscosity values and softening point values increase when increase in the nanoclay content. Consequently, the mixing temperatures and compaction temperatures of the modified asphalts increase with increase the nanoclay content to reach (170 °C). While the penetration and ductility values decrease when increase the modifier content. Regarding the penetration index of the modified asphalts, it is enhanced by increase in the nanoclay proportions. Hence, the modified asphalt with 7% of nanoclay produces the greater value of penetration index accordingly, it has a positive influence on the rutting resistance.

The Use of Crumb Rubber as Modified Bitumen for Crack Filling at Deteriorated Pavement

Crumb rubber is tire retreading waste which is classified as a hazardous material because it can pollute the environment. In an effort to create an environment free of pollution, one of the efforts is to reuse it as building material. In this research, crumb rubber will be used to modify the 60/70 penetration bitumen to have a better performance as crack filler on roads that are damaged in the form of cracks. As crack filler the material must have resistance to softening at high pavement temperatures during the day. In this study, crack filler was examined in the form of penetrating asphalt with the addition of additives, namely Crumb Rubber. The result parameters are based on ASTM D5078 standards and testing procedures based on ASTM D5329, where tests include softening point, cone penetration, resilience and asphalt compatibility testing. The results show that the addition of 27 % CR to 60/70 penetration asphalt can increase the hardness of the asphalt, the softening point value, the resilience or recovery value which means reduced vulnerability to temperature.

Use and Influence of Tire Rubber Waste Powder in Bitumen Product

Abstract The waste generation from old rubber tires has been increasing and causing environmental degradation with the escalation of vehicles number especially in the cities. Bitumen is extensively used in flexible pavement construction and as its manufacturing industries were still growing, the cost has not been much affordable. This study aimed at evaluating the possibility of a partial replacement of ordinary bitumen by tire rubber waste, with the purpose to reduce not only the amount of rubber wastes dispersed in the nature, but also the material cost, while keeping or improving the bitumen product performance. The study used rubber waste powder as partial replacement to ordinary bitumen by 5%, 10%, 15%, and 20% of its weight and, with adequate samples, properties of the bitumen product were investigated, after checking the standard quality of used bitumen 60/70 grade. It was established that more adequate results were achieved at 5% of replacement, which showed the penetration value of 61.66 tenths mm, the softening point value of 52.750C, and the viscosity of 134 sec. Regarding the cost estimation of this new bitumen, a cost reduction of around 5.3% was realized. Therefore, the use of rubber waste powder would contribute not only to the reduction of the quantity of respective waste in the environment, but also influence on the material affordability. The use of other grades of bitumen than 60/70, as well as the strength and durability performance may be a good scope for further studies.

MICRONIZED CRUMB RUBBER INFLUENCE ON INDEX PROPERTIES OF WARM ASPHALT BINDERS

Primarily, the main aim of recycling waste tires in the form of micronized crumb rubber into asphalt cement as modifiers are to enhance their engineering properties in addition to the associated solid waste management benefits. Often, these modifiers are used to achieve reasonably stiffer binders i.e.; low penetration; high softening point; and high penetration index, to realize higher resistance to deformation under the influence of traffic and temperature. The study assessed the effects of Micronized Crumb Rubber (MCR) on the penetration, softening point, and penetration index of 80-100 PEN bitumen impregnated with 2.5 % Sasobit (fixed by weight). The MCR modified warm asphalt binders were prepared by further blending with different percentages of minus 40 mesh size MCR powder (from0 – 15 % by weight of the bitumen stepped at 2.5%). Subsequently, penetration and softening point tests were conducted on each blend, and the corresponding penetration indices were evaluated. The results show that MCR addition gradually decreases the penetration values while conversely increases both the softening point values and the penetration indices as well. Thus, MCR might be used to improve the flow and thermal susceptibility resistance of warm asphalt binders

Cellulose Microfibril and Micronized Rubber Modified Asphalt Binder

Cellulose microfibrils (CMFs) and micronized rubber powder (MRP) can be derived from low or negative-cost agricultural/industrial waste streams and offer environment-friendly and cost-effective pathways to develop engineering products. This study investigated the efficacy of adding these micromodifiers on the performance characteristics of asphalt binders. In this work, samples were produced using a mixture of slow-setting anionic asphalt emulsion with various combinations of MRP (at 0, 2 and 10 wt %) and four types of CMFs (hydrophobic and hydrophilic with crystalline ratios of 86% and 95%) at 0, 2 and 5 wt %. The performance of modified asphalt samples was assessed by penetration depth (PD), softening point (SP), and penetration index (PI). Linear regression analysis showed that adding CMFs and/or MRP reduced PD and increased SP values. The type of CMFs significantly affected the performance, which becomes more distinct with the increased weight content of CMFs. While hydrophilic CMFs caused increases in SP and PI values, no clear trend was seen to determine the effect of CMF crystallinity. It was also discovered that the combined addition of CMF and MRP achieved similar PI values at lower total weight content compared to using MRP alone.

Physical, rheological and morphological characterization of modified asphalt binder with differing crumb rubber contents

Waste crumb rubber (CR) which is obtained from scrap tires can be successfully used as an asphalt binder modifier for the purpose of attaining the economic benefits with a desirable performance. The wet process was used in this study to investigate the rheological, morphological, and physical changes that would occurred to asphalt binder as a result of the interaction with different rubber contents, that is, 5%, 7%, 10%, 12% and 25%. The penetration, viscosity, softening point, ductility, Superpave performance grades, multiple stress creep recovery (MSCR) of the prepared modified binders were measured under different ageing conditions and temperature ranges. Furthermore, atomic force microscopy (AFM) scanning technique was also conducted in tapping mode to characterize the microstructure of these binders. The obtained results showed that as the rubber content increased, the viscosity and softening point values increased with a reduction in the penetration and ductility values. Rubber content of 10% was ranked as the higher percentage of rubber in terms of bumping the performance grade by at least two grades at high testing temperatures. The grading performance tests based on rutting index (G*/sin δ°) and non-recoverable creep compliance index (Jnr) showed a comparable result for ranking the stiffer binder with a greater resistance to rutting. However, most of crumb rubber modified binders failed to meet the stress sensitivity criteria of MSCR test. AFM images can be considered as a new effective and suitable tool that should be adopted for further microstructural analysis.

Influence of soft binder and rejuvenator on the mechanical and chemical properties of bituminous binders

At the end of their service life, asphalt pavements exhibit distresses such as cracking and ravelling due to the aged bituminous binder. The recycling process of reclaimed asphalt should compensate for the deteriorated binder properties. The main objective of this binder study is to compare two common recycling strategies: the use of a softer binder and a rejuvenator. Three recycling percentages, 0%, 40% and 70% of reclaimed asphalt binder were evaluated. All binder blends were prepared with similar penetration and softening point values. In order to simulate binder performance during service life, ageing protocols by means of rolling thin film oven test and pressure ageing vessel were performed. The investigation included both mechanical and chemical tests. A dynamic shear rheometer was used to assess different rheological parameters over an extensive temperature range. Linear amplitude sweep tests were performed to estimate the fatigue resistance at intermediate temperatures. Resistance to permanent deformation was assessed with a multiple stress creep recovery test. Fourier-transform infrared spectroscopy was used to assess the formation of bonds that indicate oxidative ageing after the ageing protocols. Moreover, an optimised method was introduced to calculate the carbonyl index for rejuvenated binders, which also allows to detect the presence of a rejuvenator in a bituminous binder. The results show that the inclusion of rejuvenator results in similar rheological behaviour compared to the application of a soft binder. Furthermore, the rejuvenator improves binder fatigue life without reducing the performance at elevated temperatures.

Design and optimization of polyurethane modified bitumen (PUMB) using response surface method

This paper discusses the utilization of Response Surface Method (RSM) statistical tool to determine the optimal amount of polyurethane (PU) for modifying 80/100 penetration grade bitumen. Central composite design (CCD) was used to develop an experimental design matrix where bitumen and PU are designated as the factors while penetration, softening point and viscosity are designated as the response. Numerical analysis of polyurethane modified bitumen (PUMB) shows that the optimal amount of PU in the modification of the bitumen is 5%. Verification of the chosen model shows that it is in consistent with the experimental value since the percentage error is less than 5%. Result of the consistency test shows that the addition of 5% PU resulted in higher penetration and viscosity values but lower softening point value, which in consequent improve bonding strength as the flow of bitumen is reduced.

Properties of modified asphalt mixtures with additives of fillers materials

In past, the use of by-product materials such as cement kiln dust and fly ash powders, especially in the field of highway pavements has received increasing attention. The aim of this research is to investigate the physical properties of the modified asphalt binder with additives of filler types such as cement kiln dust, fly ash, and metakaolin powder. Then, to assess the Marshall properties of modified asphalt mixtures. Three fillers containing 3%, 5%, and 7% by weight were used. The modified asphalt binder was mixed by a mechanical mixer having a revolution rate of (2000 rpm.), for mixing time (5 to 20) min. at a temperature of 140 °C. Results showed that the use the additives was beneficial in improving the physical characteristics of the asphalt cement. Overall, it was found that the penetration grade reduced and softening point values increased and the susceptibility of temperature was enhanced. Furthermore, the results of the tested specimens, the 5% of CKD, 5% of fly ash and 7% of MK were sufficient to improve the physical characteristics and Marshall properties of modified asphalt binder mixtures. In addition, the results obtained from the Marshall test show that the maximum stability for 7% of MK, 5% of CKD, 5% of fly ash, and control asphalt mixtures are (14.4, 13.6, 11.7 and 10.4) kN, respectively.