Higher Marshall Stability Research Articles

Enhancing asphalt mixture performance through waste plastic modification: a comprehensive analysis of optimal compositions and volumetric properties

ABSTRACT This study explores the innovative use of waste plastic, including polyethylene terephthalate (PET), high-density polyethylene (HDPE), and polyvinyl chloride (PVC), as additives in VG30-grade bitumen for road construction. The research focuses on precise proportions of plastics to achieve optimal performance, utilizing a meticulous methodology involving laboratory tests, particularly the Marshall Stability (MS) test. The investigation reveals that a 3.0 % waste plastic content, specifically with 100% PET, and 5.5 % bitumen content results in the highest MS, demonstrating a 73.07 % improvement over the control mix. Additionally, the study examines the nuanced relationships between waste plastic incorporation, bitumen content, and volumetric properties such as air voids, bitumen volume, voids in mineral aggregate, and asphalt-filled voids. The findings emphasize the importance of carefully balancing these factors to achieve the desired properties in the modified asphalt mix. Notably, the 5.5 % bitumen composition consistently demonstrates superior performance across various parameters. The research contributes valuable insights into the potential enhancements brought about by waste plastic additives, particularly 100 % PET, in asphalt mixtures. The identified optimal compositions enable the development of sustainable and high-performance asphalt materials for road construction, meeting the demand for eco-friendly solutions in infrastructure development.

A novel approach to warm mix asphalt additive production from polypropylene waste plastic via pyrolysis

The utilization of waste plastics as an additive in warm mix asphalt (WMA), which is an environmentally friendly technology, by pyrolysis method is an emerging concept. In this study, WMA additive was synthesized from char (C) and wax (W) products obtained from the pyrolysis of polypropylene (PP) type waste plastics. Seven different pyrolysis modified bitumen were prepared as PP 6%C, PP 6%C-3%W, PP 6%C-6%W, PP 6%C-10%W, PP 3%C-6%W, PP 1%C-6%W and PP 6%W. Base bitumen and Sasobit® 3% (by weight of bitumen) modified bitumen were used as control groups. The rheological properties of the binders were investigated by Rolling Thin Film Oven, Pressure Aging Vessel, Rotational Viscometer, Dynamic Shear Rheometer and Bending Beam Rheometer tests, and the morphological properties were analyzed by Scanning Electron Microscope, Fourier Transformed Infrared Spectroscopy and Zeta Potential analysis. Asphalt mixture performance characteristics were evaluated by Marshall Design, Hamburg Wheel Tracking and Thermal Stress Restrained Specimen Tests. Binder test results demonstrated that with the addition of PP 6%C-6%W and Sasobit® 3%, the viscosity of bitumen decreased significantly and accordingly the plant temperature reduced by 14ºC and 9ºC. Besides, PP 6%C-6%W modified bitumen performed better than base bitumen at low, medium and high temperatures. Sasobit® 3% improved the high temperature performance of the bitumen. The additive-bitumen modification mechanism involved physical process. Furthermore, the additives were well distributed in bitumen and no agglomeration was observed. WMA-1 (PP 6%C-6%W) and WMA-2 (Sasobit® 3%) have 5% and 9% higher Marshall stability than hot mix asphalt (HMA), respectively. Moreover, the addition of PP 6%C-6%W and Sasobit® 3% increased the rutting resistance of the mixture by 9% and 21%, respectively. Moreover, PP 6%C-6%W improved the low temperature performance of the mixture by decreasing fracture temperature by 3ºC and increasing the fracture strength by 15%. All in all, PP pyrolysis products have strong indicators to become a WMA additive.

Improvement of pavement engineering properties with calcium carbide residue (CCR) as filler in Stone Mastic Asphalt

Characteristics of pavement material are crucial factors in improving the stability and durability of asphalt pavement due to the poor performance of traditional asphalts. Reusing industrial waste in asphalt concrete production can address these concerns, reduce environmental problems and preserve resources. There have been few studies on the effects of using industrial waste materials on Stone Mastic Asphalt (SMA) properties. This paper examines the impact of Calcium Carbide Residue (CCR) as a filler in SMA. The study evaluates control samples, those with Rock Powder (RP) and Ordinary Portland Cement (OPC) filler, and those with CCR using Marshall stability (MS) and Indirect Tensile Strength (ITSdry and ITSsat) tests. Results show positive effects of CCR and RP on asphalt sample strength. The highest MS, MQ, and TSR values were observed in samples containing CCR80 %+RP20 %. These indices increased 45 %, 35 %, and 51 %, respectively, compared to control samples. The alkaline CCR material forms strong bonds with acidic bitumen, producing asphalt more resistant by 97 % compared to control samples. SMA modified with CCR + RP was also found to be less sensitive to water damage than traditional SMA with RP or OPC filler. The rough texture of CCR may positively affect the strength and durability of asphalt mixtures against moisture damage. Using CCR as a filler in SMA can enhance pavement engineering properties, reduce production costs and environmental problems, and develop sustainable asphalt mixtures for practical application. The main novelty of this research is the use of CCR and RP combination in SMA mixtures.

USING NANOCLAY HYDROPHILIC BENTONITE AS A FILLER TO ENHANCE THE MECHANICAL PROPERTIES OF ASPHALT

Higher traffic loads on the wheels, increased traffic volumes, and exposure to changing weather conditions result in increasing the road stresses and strains, putting the paving layers in danger of degradation such as fatigue, stripping, cracking, and rutting. A tremendous number of studies and trials have been conducted to modify asphalt to have a longer service life, less maintenance, be cheaper, and be more environmentally friendly. Recently, nanotechnology has proven very beneficial in all industries, including asphalt. It can be used to enhance the asphalt's mechanical properties. Using nano clay in asphalt is expected to improve the mechanical properties and the service life of the asphalt. So the main objective of this study is to investigate the performance of nano clay hydrophilic bentonite in improving the physical characteristics of asphalt concrete. This study uses nano clay with various replacement ratios as fillers to the ordinary used limestone filler in asphalt concrete. The used replacement percentages were (0%, 20%, 40%, 60%, 80%, and 100). The experimental tests that were conducted in this study include Marshall Stability (MS), Marshall Flow (MF), voids in mineral aggregate (VMA), theoretical maximum specific gravity (Gmm) and air voids (AV).The results showed a noticeable enhansment in the behavior of the asphalt mix with increasing the replacement percentage by nanoclay. Also, it was found that the 60% replacement rate by nanoclay has the highest Marshall stability with an increase of 93%, also the lowest flow with a decrease of 25% compared to the control asphalt mix.

Using nanoclay hydrophilic bentonite as a filler to enhance the mechanical properties of asphalt

Higher traffic loads on the wheels, increased traffic volumes, and exposure to changing weather conditions result in increasing the road stresses and strains, putting the paving layers in danger of degradation such as fatigue, stripping, cracking, and rutting. A tremendous number of studies and trials have been conducted to modify asphalt to have a longer service life, less maintenance, be cheaper, and be more environmentally friendly. Recently, nanotechnology has proven very beneficial in all industries, including asphalt. It can be used to enhance the asphalt's mechanical properties. Using nano clay in asphalt is expected to improve the mechanical properties and the service life of the asphalt. So the main objective of this study is to investigate the performance of nano clay hydrophilic bentonite in improving the physical characteristics of asphalt concrete. This study uses nano clay with various replacement ratios as fillers to the ordinary used limestone filler in asphalt concrete. The used replacement percentages were (0%, 20%, 40%, 60%, 80%, and 100). The experimental tests that were conducted in this study include Marshall Stability (MS), Marshall Flow (MF), voids in mineral aggregate (VMA), theoretical maximum specific gravity (Gmm) and air voids (AV). The results showed a noticeable enhansment in the behavior of the asphalt mix with increasing the replacement percentage by nanoclay. Also, it was found that the 60% replacement rate by nano clay has the highest Marshall stability with an increase of 93%, also the lowest flow with a decrease of 25% compared to the control asphalt mix.

The Effect of Cow Dung Ash as A Filler on The Mechanical Characteristics of Hot Mix Asphalt

Highway pavements are being exposed to increasing traffic loads and severe environmental conditions, resulting in reduced service life. A lot of studies have been conducted to modify asphalt by using different materials, especially to replace the ordinary filler. Because the behaviour of the hot asphalt mix is influenced by the fillers. The use of unusual materials as fillers in asphalt mixes can help to improve the mix’s characteristics. As a result, this study uses cow dung ash materials with various replacement ratios as fillers to investigate the mechanical properties of asphalt. In the asphalt mix, a replacement percentage of limestone (0%, 10%, 20%, 30%, 40%, 50%, 60%, 80%, and 100%) was utilized. After that, various tests were performed such as Marshall stability, Marshall flow, voids in mineral aggregate, theoretical maximum specific gravity, air voids. The results revealed a significant improvement in the asphalt mix’s behaviour, as well as an increase in the replacement percentage. According to the findings, the 50% replacement rate has the highest Marshall stability which is equal to 11.11 with a 33.5% rise and the lowest flow of 3 with a 17.83% decrease when compared to the reference mix. As a result, cow dung ash can be used as a filler to modify the mechanical properties of the asphalt mix.

Volumetric and Abrasion Loss Properties of Asphalt Mix Modified with Used Toner Ink

The research centered on the effect of used toner ink (UTI) as bitumen modifier in asphalt mix as paving materials with respect to the volumetric properties and durability. In this research, UTI are proportioned into the asphalt binder for mixing the asphalt concrete in percentages of 2%, 4%, 6%, 8% and 10%. Marshall and Cantabro loss tests were carried out on the hot asphalt mix. All the percentage proportion of used toner added was evaluated with the following parameters: voids in the mineral aggregates (VMA), voids in total mix (VTM), voids filled with asphalt (VFA), Marshall stability, flow value, and specific gravity. It was observed that asphalt mix with UTI performed better under loading as the UTI in the asphalt mix increases. The highest Marshall stability was observed to be 32,352N at 6% UTI, also there is reduction in the optimum bitumen content as the UTI, which helps in reducing the amount of bitumen needed in the course of asphalt pavement construction. In respect of this research further asphalt pavement design can be modified to provide pavement that can be more sustainable and durable over a long period of time, thereby reducing the cost of asphalt mix production.

Performance evaluation of waste palm oil fiber reinforced stone matrix asphalt mixtures using traditional and sequential mixing processes

Asphalt pavement in tropical countries like Malaysia faces severe distresses. Thus, the use of more resistant and stable asphalt mixtures on the surface layer like stone matrix asphalt concrete (SMAC) is encouraged. The performance-related properties of asphaltic concrete are highly influenced by the mixing process and the asphalt mixtures homogeneity and segregation are pivotal issues affecting asphaltic concrete production. Malaysian palm oil industry generates a large amount of waste palm fiber (WPOF) which are largely discarded. This study investigates the feasibility of utilizing WPOF as a stabilizer in SMAC and evaluates the influence of two different mixing processes (traditional and sequential) on its properties The SMAC mixtures were reinforced with various content of WPOF, 0–0.6% by weight of the total mix and evaluated for volumetric and mechanical properties. Several standard laboratory test methods were used to examine the mixtures: Marshall properties, drain down test, Cantabro, stiffness modulus, moisture damage test. The study revealed sequential mixing as a more viable mixing alternative for SMAC, as it shows lower drain down, air void, and optimum bitumen content with higher Marshall stability and voids in mineral aggregate values. While for the mechanical properties the sequential mixing shows higher moisture resistances, stiffness modulus, and less Cantabro loss for all mixture’s types compared to the convention blends. It was observed that the optimum WPOF dosage is 0.3% for both mixing processes, Though, the sequential mixing shows improved mechanical properties. These improved properties are probably due to improving coating and proper dispersion of mixing materials during the mixing process. In conclusion, utilizing WPOF as stabilizers improve SMAC mixtures properties whereas, the sequential process produces better properties even at marginally lower OBC and mixing time.

POTENTIAL USE OF 'ENSET' FIBER ASH AS PARTIAL REPLACEMENT OF CONVENTIONAL FILLER MATERIAL IN HOT MIX ASPHALT

The main problems in road construction and maintance work in Ethiopia availability of a large amount of appropriate quality materials in road construction sites, aggregates in different size fractions are not readily obtainable, necessitating their procurement from long distances, thereby causing an exorbitant increase in construction costs. One of the main problems in constructing the asphalt paving mixture is obtaining a sufficient amount of filler material from crushing fine rock material and low percent using ordinary Portland cement (OPC), hydrated lime (HL) and marble dust. To overcome this problem, it is important to come across alternative filler material to address this gap using naturally available material. Currently, renewed attention has been given to the use of ‘waste’ materials instead of conventional aggregates in pavement construction. This research study investigates the potential use of ‘Enset’ fiber ash as a partial replacement of conventional filler material in hot mix asphalt supported by experimental laboratory investigation. In order to achieve this study, purposive sampling techniques were adopted to select the sample size and location. The study evaluated the potential of ‘Enset’ fiber ash as filler for the design of dense-graded hot mix asphalt by referencing traditional filler control mix procedures based on standard specifications, and a crush rock filler was utilized as a conventional filler material as a control for comparison. The Marshal Stability and Rutting Test (RT) was conducted to determine the HMA specimen's performance. Several HMA specimens were prepared using aggregate blend according to ASTM D 1559 with four different percentages of ‘Enset’ fiber ash (EFA) of 15%, 25%, 35% and 45% filler replacement the total filler weight used in the control mix. Specimens were prepared and tests performed according to EN 12697-22 procedure-B for rutting test. All HMA properties were taken at 4% air void and determined their optimum bitumen content (OBC). Almost the same result with the control mix was observed in the study at 15% and 25% of the ‘Enset’ fiber ash (EFA) replacement. However, higher Marshall Stability, a lower void filled with asphalt, better flow, a good void in mineral were observed at 25% ‘Enset’ fiber ash (EFA) replacement. At this rate, the rutting performance is less than that of the control mix but is within the specifications of 2.78mm and 2.9 mm of rutting depth less than 6mm that satisfies the EN 13108 requirement. As a result, Enset fiber ash filler can replace traditional filler material up to 25% of the total filler weight used in this study. It was recommended to use ‘Enset' fiber ash (EFA) as a filler material as a partial replacement in a bituminous paving mixture up to the specificed percentage by weight replacement.

Utilisation of Mining Waste from the Steel Industry, Ladle Furnace Slags, as a Filler in Bituminous Mixtures of Continuous Grading

Road construction is an activity that involves a large consumption of raw materials, with the consequent high environmental impact. For this reason, various research projects are being developed in which waste is used as a raw material for bituminous mixtures. This avoids the extraction of raw materials, reduces the environmental impact and reduces greenhouse gas emissions. In this research, the incorporation of ladle furnace slag as a filler for continuous grading bituminous mixtures was evaluated. Firstly, the ladle furnace slag was chemically and physically characterised and its suitability for use as a filler was determined in accordance with the regulations. Subsequently, bituminous mixtures were conformed with the slag and also with commercial fillers, calcareous and hornfels, in order to compare the results. Finally, the physical properties, Marshall stability and the effect of water were determined with the immersion–compression test on all families of samples. The results showed that the mixes conformed with ladle furnace slag had higher Marshall stability, less variation due to the effect of water and acceptable physical properties. Consequently, the suitability of utilisation of these slags in bituminous mixtures could be confirmed.

Performance of asphaltic concrete modified with recycled crushed bricks

The pavement industry relies greatly on this conventional material in constructing the road. However, the shortage of the mined material has led to the need of finding alternative with local materials to partially substitute the asphalt components. The conventional pavement industry also contributed to thermal and greenhouse emission resulting from the mining activities. In addition, throughout the year, the amount of construction and demolition (C&D) waste generated from civil construction activities particularly in Malaysia is increasing in alarming rate. Recycling the C&D waste specifically in bricks is viewed as reasonable potential as aggregate modifier in the impulse for greener and sustainable asphalt pavement production. In this paper, recycled crushed bricks (RCB) is introduced to bituminous wearing course as partial replacement for coarse aggregates. The coarse aggregate is partially replaced with RCB in proportions of 0%, 10%, 20%, 30% and 40% by weight. This study summarizes the results of laboratory evaluation of Los Angeles Abrasion Value, Aggregate Crushing Value and Marshall Test. Results show that asphaltic concrete modified with 10% RCB has the lowest abrasion and crushing values which were 20.2% and 30% respectively. Similarly, the mix has the highest Marshall Stability and lowest flow which 15.61 kN and 3.37 mm respectively. Thus, partial replacement of coarse aggregates with 10% RCB in bituminous mix is suitable to be used in wearing course and can be used as alternative material in bituminous mix to reduce the dependency on natural aggregates and utilize the C&D waste efficiently.

Increasing the Stability of Asphalt Concrete Mixture Using Crumb Rubber

Stability is a measure of the strength of an asphalt mixture in resisting deformation due to loading. If a road construction structure cannot withstand the existing load, it will result in road damage that endangers road users. This study aims to improve the stability of the asphalt concrete mixture with the use of crumb rubber. Crumb rubber is used because it has good resistance and elasticity. The research was conducted experimentally by making test objects in the laboratory. In this study, five variations crumb rubber (2%, 4%, 6%, 8%, and 10% of the weight asphalt mixture) were carried out with the size of the powder retained on a 40 sieve. Marshall test and analysis of volumetric was carried out to determine the characteristics of the asphalt-concrete mixture. The results showed that the highest Marshall stability was obtained at 10% crumb rubber with a stability value of 1422 kg. The use of rubber powder can significantly increase the strength and quality of the asphalt-concrete mixture. Thus, crumb rubber can be used, and this percentage can be used as a reference in the manufacture of asphalt-concrete mixtures in order to obtain good road pavement quality.

Evaluation of The Performance of Hot Mix Aspahalt with Natural Rubber (Latex) for Asphalt Concrete- Binder Course (AC-BC)

This study aims to measure the performance of the Hot Mix Asphalt for Asphalt Concrete Binder Course (AC-BC) with addition of natural rubber (latex) at variations of 0%, 2% and 3% by weight. The method used in this study is an experimental method in a laboratory that consists of natural aggregate testing, rheology testing for asphalt pen 60/70 and asphalt pen 60/70 plus natural rubber (latex) and AC-BC mixture testing. The method used is Marshall Test to obtain optimum asphalt content (OAC) and another method consists of UMATTA Resilient Modulus Test and strain controlled Four Points Fatigue Test. The addition of natural rubber in the AC-BC mixture reduced the optimum asphalt content (OAC) and increased the Marshall stability value, the optimum percentage is 3% natural rubber (latex) with the lowest OAC of 5.4% and the highest Marshall stability. The UMATTA test with 2% natural rubber (latex) resulted in the highest Resilient Modulus value compared to the other two blends. Fatigue testing at strain 500 I¼Iµ, 600 I¼Iµ, and 700 I¼Iµ resulted that the mixture of AC-BC with 3% natural rubber produced the highest fatigue life value compared to the other two mixes. In general, the result of testing and its analysis concluded that the use of natural rubber (latex) can reduce the use of asphalt in the mixture. This can be relified by decreasing the value of OAC in the mixture with natural rubber. The mixture with 3% natural rubber (latex) gives the highest resistance to fatigue cracks in the laboratory.Â

Investigating the Marshall and Volumetric Properties of Asphalt Concrete Containing Reclaimed Asphalt Pavement and Waste Oils Using Response Surface Methodology

This research aimed to use response surface methodology (RSM) for investigating the Marshall Stability (MS), flow and Voids in Mineral Aggregates (VMA) of asphalt concrete containing different percentages of Reclaimed Asphalt Pavement (RAP) and rejuvenated by different percentages of waste cooking and engine oil. Variables of RAP content in 3 different levels of 25, 50 and 75% (by the weight of total aggregates) and waste oils content in 3 different levels of 5, 10 and 15% (by the weight of total binder) were selected. Quadratic and linear two factor interaction models were well fitted to the experimental results. Analysis of variance showed that the models were capable to well predict the MS, flow and VMA of the mixtures, and the terms of oil and RAP content and type of oil are significant. MS, flow and VMA increased with increasing RAP content and decreased with increasing oil content. Results also reveal that higher MS, flow and VMA values are resulted by using WEO than using WCO. Some interaction effects were found between RAP content, oil content and type of oil on the responses. Optimization analysis showed that using 10.6% of WCO and 15% of WEO, allows a maximum RAP incorporation of 75 and 51.77%, respectively, by which the properties are similar to control mix. Use of the rejuvenators allows using high RAP content without sacrificing the properties of the mixtures.

Laboratory investigations and performance evaluation of stone matrix asphalt as a wearing course using three different fibers

ABSTRACT Bituminous mixtures are used as wearing and base course layers in a pavement structure and the performance of these mixes can be defined by its resistance against deformation, fatigue cracking, damage due to moisture and overall stiffness of the mixture. Rutting is one of the most important factors that lead to permanent failure of flexible pavements. The stone matrix asphalt (SMA) mixture is known to be highly rut resistant than other conventional wearing courses such as bituminous concrete. This paper describes the experimental examination conducted on stone matrix asphalt (SMA) mixes prepared using VG 30 grade of bitumen and different types of fibers such as cellulose fiber, coconut fiber, glass fiber and jute fiber as their additives. Results were then collated with SMA mixes prepared with different types of fibers. Investigation work comprises SMA mix design, static indirect tensile strength (ITS) and drain down test. From the test results, it was perceived that SMA with cellulose fiber has higher Marshall Stability and slightly lower drain down percentage as compared to all other fibers used. But indirect tensile strength for SMA mix prepared with jute fiber was higher than all other mixes.

ÇELİK FİBERLİ ASFALT BETONU KARIŞIMLARIN MARSHALL STABİLİTESİ VE İNDİREKT ÇEKME MUKAVEMETİNİN İNCELENMESİ

One of the conductive fiber types used in the mixtures in order to provide the desired performance by reducing the deterioration of asphalt concrete coatings during the project is steel fibers. In recent years, studies on the use of steel fiber to provide self-healing property by heating the layers during the repair phase have attracted attention. In order to evaluate the economy of steel fiber layers, it is necessary to know the mechanical properties of these layers before they come into repair. In this study, the abrasion made Marshall design to binder mixtures, according to the design result, at the rate of 0.1%, 0.15% and 0.2% of the total weight of aggregate and bitumen, a steel fiber of 10 mm length and 1 mm diameter was added to the mixtures. After the first Marshall stability, conditioned indirect tensile strength tests on the mixtures, the same tests were applied again without removing the samples from the device. As a result, the highest Marshall stability and conditioned indirect tensile strength were obtained in binder mixes with 0.10% steel fiber compared to the unadulterated, while in the additive wear mixture tests, close to the additive-free or lower results were obtained.

Evaluation of Polymer Modified Asphalt Mixtures in Pavement Construction. (Dept. C)

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A study on the properties of cement grouted open-graded bituminous concrete with brick as aggregates

Cement grouted open graded bituminous mixes are cement slurry injected bituminous mixes which had 20 to 35% air void initially. This paper studies the effect of air voids, water-cement ratio and aggregate type on the performance of cement grouted macadam. Natural stone aggregates, crushed first-class brick aggregates and crushed overburnt brick aggregates are used in this analysis with three different air voids (18%, 21%, and 24%) and with three different cement grouts (0.5w/c, 0.6w/c, and 0.7w/c). Grouted samples with 24% air voids show superior performance followed by 21% and 18% air void samples, respectively. A reduction of up to 35.33% in rut depth and an increase up to 144.55% in fatigue life was recorded for grouted macadam when compared with conventional mixes. It was also observed that the grouted macadam has higher Marshall stability, rut resistance, fatigue life and moisture susceptibility than the conventional mixes.

Laboratory performance of asphalt mixture with waste tyre rubber and APAO modified asphalt binder

ABSTRACT In order to further explore the performance of mixture with waste tire rubber (WTR) and amorphous poly alpha olefin (APAO) modified asphalt, the 12%WTR+4%APAO and 15%WTR+4%APAO modified asphalt mixtures were selected as research objectives. The asphalt mixtures with matrix asphalt, WTR modified asphalt, and SBS modified asphalt were prepared for comparative analysis. Through the mixture design, the optimum asphalt-aggregate ratio of five asphalt mixtures was determined respectively. The volumetric parameters and resilient modulus were studied. The laboratory performances were studied by standard Marshall stability test, wheel tracking test, immersion Marshall test, freeze–thaw splitting test, indirect tensile strength test, indirect tensile fatigue test, and Marshall stability after long-term aging test. Compared with the other three asphalt mixtures, the results showed that the 12% WTR+4%APAO modified asphalt mixture had the highest Marshall stability and high-temperature performance. While the 15% WTR+4%APAO modified asphalt mixture had better permanent deformation resistance at high temperatures, moisture stability, aging resistance, and relatively good fatigue performance. The statistical hypothesis test results also confirmed that WTR/APAO modified asphalt has a significant effect on mechanical properties. Based on the results of various performance, the 15% WTR+4% APAO was the optimal content for asphalt mixture.

Effect of Silica fume on Cold Mix Asphalt Mixture

The cold asphalt emulsion mixture CAEMs is a mixture consisting of asphalt emulsion with aggregate mixed at room temperature. CAEMs is the most preferred layer in recent times as it is most safe in terms of the lack of environmentally friendly and healthy volatile fumes. Many studies have demonstrated that silica fume has significant effects in improving the engineering properties of asphalt binder and mixture.Several requirements were conducted on compacted modified CAEMs with silica fume during the practical program of this research, such as Marshall stability test, density, air voids, indirect tensile strength (exposed to freezing and thawing conditions and not exposed to it and the effect of moisture in addition to non-destructive examination using sound waves. Results of this study prove that using silica fume improved the behavioral properties of cold mix. Higher Marshall Stability (100%), Higher tensile strength(219%) than the conventional mixture( without additives) and had a positive effect on the resistance to freezing and thawing condition.