# Effect of Sodium Chloride on Properties of Bitumen Md. Shariful Islam Abstract-Nowadays a lot of modifications are taking place throughout the world to develop the existing highway materials to fulfill the demand of increased vehicles. People are at the trend to innovate something new that can do better than it was. Some material produce a good effect and enhance the strength as well as qualities of bitumen. On the other hand, some are responsible for the adverse on the bitumen. In saline areas like coastal regions, the salts play a significant role in the bituminous pavements. Water of sea nearly contains 3% sodium chloride, and evaporation of intake bodies of water has produced huge and extensive deposits of it. We can be economically benefited if salt is used as an admixture to bitumen. But we do not even know the impact, good or bad of the mixing of salt with bitumen. The objective of this paper to find out whether it is desirable or not taking various proportion salt with bitumen and doing the specified test of bitumen. It is observed from the laboratory test that the penetration and ductility values are gradually increased with increase of salt content. The flash point, fire point, and softening point value are stepwise reduced as a percentage of salt content increased. Moreover, it reduces the stability of roads. Mixing of salt to bitumen upgrades workability and it is beneficial in the economical point of view. Finally, moisture effect test on the bituminous mix with the inclusion of salts shows the degradation of strength due to moisture movement. # I. Introduction ituminous mixes are most commonly used all over the world in pavement construction. Under normal circumstances, conventional bituminous materials if designed and executed properly perform satisfactory. But for applications like roundabouts or where traffic is extremely heavy, stiffer mixes are required which can have large fatigue life and more resistance permanent deformation. Most publications ascribe moisture damage to variables like bitumen properties, aggregate characteristics, hot mix processing, bituminous mixture characteristics, quality control during construction, nature of water at the interface, dynamic effect of traffic loading, type, and properties of anti-stripping additives, and others. The great diversity of variables and differences in earlier research results reported make a prediction of moisture sensitivity difficult. Most mechanistic design methods for bituminous pavements mainly base on fatigue and rutting as the primary design criteria. However, SHRP's mechanistic/analytical approach to pavement design proposed the need to consider resistance to moisture damage as a factor in selection and proportioning of binders and aggregates (McGennis et al., 1995). The Coastal area, pavement often come across with saline water. In this area, the salts particularly sodium chloride plays an important role in the stability as well as durability of roads. In this situation, the effect of salts on properties of bitumen is important for design and maintenance of the pavements. The present status of literature, indicate that a little work has been conducted to determine the behavioral changes in the bituminous pavements in the present of salts. In this paper, an attempt has been undertaken to study the effect of salts on varies properties of bitumen. # II. # The Objective of Study In recent years, a significant achievement has been made the study in the different field of engineering Also various causes have been determined to take appropriate measures against the determination and detrimental effect. In general, the presence of alkalis and salts produce a harmful on the behavioral aspects of binding materials. In these studies, an attempt has been made to quantify the adverse effects in term of some specific standard tests. The objective of this studies are To the effect of salts on the properties of bitumen. To determine the variation of strength with the inclusion of salts. To observe the effect of water on the strength of bituminous mixes with the inclusion of salts in bitumen. To carefully examine the use of salts in the bitumen regarding various properties such as penetration, solubility, ductility, etc. # III. # Tested on Bitumen To determine its behavior and its suitability a variety of tests have been specified by institutions like ASTM, I.S.I, Asphalt Institute, And B.S.I. The various tests of bitumen are followed: ? Penetration test: The penetration tests determine the hardness or softness of bitumen by measuring the depth in one-tenth in millimeter to which a standard loaded needle will penetrate vertically in five seconds. The flash point of a material is the lowest temperature at which the vapour of a substance momentarily takes fire in the form of a flash under specified condition of test. The fire point is the lowest temperature at which the material gets ignited and burns under specified conditions of test. where the bitumen binders are used, it is of significant importance that binders from the ductile thin film around the aggregates. This serves as a satisfactory binder in improving physical interlocking of the aggregates. The binder material which does not possess sufficient ductility would crack and thus provide previous pavement surface. It has been started by some agencies that the penetration and ductility properties go together, but depending upon the chemical composition and the type of crude source of the bitumen, sometimes it has been observed that the above statement is incorrect. It may hence be mentioned that the bitumen may satisfy the penetration value, but may fail to satisfy the ductility requirements. Bitumen paving engineer would however want that both test requirements be satisfied in field jobs. Penetration or ductility can not in any case replace each other. The ductility is expressed as the distance in centimeters to which a standard briquette of bitumen can be stretched before the thread cracks. The test is conducted at 27±0.5 ? Cand a rate of pull of 50±2.5 mm per minute. The test has been standardized by the ISI. # Global Journal of Researches in # Effect of Water on Bituminous Mixes One of the complex problems in the field of highway engineering, existing since bitumen paving technology came into existence is stripping. The term stripping, as employed by highway engineers, denotes the occurrence of adhesion failure or weakening of the cohesive bonds within the aggregate asphalt system.It isconsidered as great economic loss and engineering failure regarding proper mixture design. Majidzadeh.k (1969) stated that the factors affecting the adhesion failure phenomenon are innumerable. They include the material characteristics, construction techniques, and diversified environmental conditions. They are displacement, film rupture, and detachment and pore pressure theories. Of course, it is obvious that owing to the complexities of material composition and diversity of environmental conditions, no single mechanism may be adequate to explain the stripping phenomenon in bituminous mixtures. The concepts of the theories are briefly summarized as follows: ? Displacement Concept: According to this theory the binder aggregate function in the presence of water becomes thermodynamically unstable and reacts to more stable position [Lee,A.R] 1954. It is generally believed that, to displacement phenomena to be initiated in a mixture, the binder aggregate interface should become exposed to the water phase. That is well, the coated aggregate may not exhibit any binder displacement unless the continuity of aggregate coating is destroyed. ? Detachment Concept: The theory attributes the adhesion to a thermodynamic replacement of the bitumen by a thin film of water that may come from either outside or from within the aggregate while from the bitumen coating remains intact [Hughes, A.R]I 1960). The characteristics of the interface are believed to be very important in the detachment process. The water reaching the interface become intimately associated with the lattice of the mineral surface. ? Pore Pressure Concept: It has been postulated that the buildup of pore pressure in the mixture of high void content may result in stripping phenomena [Halberg, S] 1950. That is, on a wet surface of bituminous pavement additional forces due to traffic also act and these greatly exceed the thermodynamic forces. In a saturated pavement under dynamic load, water is pressed into the pavement in front of the moving load and sucked out behind the wheel contributing to the stripping phenomena. Among these four concepts, the displacement and detachment theories can be classified as the primary causes of stripping and pore pressure, film rupture concepts in fact only contributing to the phenomena. # VI. Effect of Mixture Density on Stripping There are primarily three perquisites for the occurrence of stripping phenomena in bituminous mixtures: the presence of water in a pavement, repeated load application and the physiochemical nature of the bituminous aggregate system. To eliminate or reduce the chances of stripping, one should attempt at least one of these factors. From the pavement design point of view, the water present in the pavement can be reduced by decreasing the void content of the bituminous mixtures. This approach could be considered as one of the preventive measures in the construction of bituminous paving using the physio-chemically unstable bituminous aggregate system.111 VII. # Preparation of Compressive Strength test Specimen The mix proportion of cement fine aggregate and coarse aggregate is 1:2:4.The water-cement ratio is 0.50. Test for compressive strength is carried out on a cube. American Society for Testing Materials ASTM C39/C39M provides Standard Test. For cube test the types of specimen each cube 10cm X 10 cm x 10 cm is used. After 24 hours these molds are removed, and test specimens are put in water for curing. The top surface of these specimens should be made even and smooth. These specimens are tested by compression testing machine after three days, seven days curing or 28 days curing. Load at the failure divided by area of specimen gives the compressive strength of concrete. # Conclusion Sodium chloride (Nacl) is a crucial factor for increasing the different properties of bitumen. But sometimes it has negative impacts as reducing the strength of bituminuous mixes. From the test values, it is clearly shown that, the penetration and ductility increases with the increases of salt content (percentage). On the other hand, flash, fire point, solubility decreases with increases of salt content. From the above graph, it is concluded that, tolerable limit of salt varying from 0% to 5%. ![Engineering ( ) Volume XIx X Issue I Version I 15 Year 2019](image-2.png "") 1![Figure 1: Penetration test apparatus ? Softening point test: The softening point test is the temperature at which the substance attains a particular degree of softening under specified condition test .The softening point of bitumen is usually determined by ring and ball test.](image-3.png "Figure 1 :") 2![Figure 2: Softening point test apparatus ? Flash and Fire point test: Flash and fire point tests is conducted on bitumen to know the safe mixing and application temperature values of particular bitumen grade.The flash point of a material is the lowest temperature at which the vapour of a substance momentarily takes fire in the form of a flash under specified condition of test. The fire point is the lowest temperature at which the material gets ignited and burns under specified conditions of test.](image-4.png "Figure 2 :") 3![Figure 3: Flash and Fire point test](image-5.png "Figure 3 :") 4![Figure 4: Ductility test ? Specific Gravity test: The density of a bituminousbinder is a fundamental property frequently used as an aid in classifying used in paving jobs. In most applications, the bitumen is weighted, but finally, in use with the aggregate system, the bitumen content is converted in volume basis. Thus an accurate density value is required for conversion of weight to volume. The specific gravity is greatly influenced by the chemical composition of the binder. Increased amounts of aromatic type compounds caused an increase in the specific gravity. The test procedure has been standardized by the ISI.](image-6.png "Figure 4 :") 56![Figure 5: Experimental setup of compressive strength VIII.](image-7.png "Figure 5 :Figure 6 :") 789![Figure 7: (c) variation of ductility and (d) softening value concerning salt content.](image-8.png "Figure 7 :EFigure 8 :Figure 9 :") © 2019 Global JournalsEffect of Sodium Chloride on Properties of Bitumen ## Acknowledgement My utmost gratitude goes to Omnipotent ALLAH, without whose mercy and blessing, this work would not been possible. I would like to first thank my beloved Professors, Department Of Civil Engineering, Rajshahi University of Engineering & Technology (RUET), for their guidance, encouragement, patience, kind help and valuable suggestions for successful completion of this work. My completion of this research could not have been accomplished without the support of my class mates, their technical advice and supports helped and inspired me. Finally, to my caring, loving, and supportive mom and dad: my deepest gratitude. Your encouragement when the times got rough are much appreciated and duly noted. * An investigation of asphalt paving mixtures containing rubber additives, Masters diss WHAlocoke Source: OAI.1954 University of Kentucky * American Society for Testing and Materials (ASTM) D 2726, D 1074 D1075, C29 and C128 1979 * Utilization of Waste Plastic as a Strength Modifier in Surface Course of Flexible and Rigid Pavements SAfroz KS BSk Prasad 2012 * Additives have Potential to Improve Pavement Life. Scranton Gillette Communications, Roads and Bridges JWButton DNLittle 1988 26 * Improvements in Rolled Asphalt Surfacing by Addition of Organic Polymers JHDenning JCarswell 1981 21 Transport and Road Research Laboratory, United Kingdom * A Review of the Effects of Salinity on Road Pavements and Bituminous Surfacings, Unsaturated Soils: Theory and Practice DeCarteret RSBuzzi OFityus S 2011. 2010 Thailand Kasetsart University * Use of Waste Polythene in Bituminous Concrete Mixes ProfBiswanath Prusty 2012 Mahabir Panda * Sulphur Asphaltic Concrete on Three Ontario Test Road HJFromm GjaKennepohl Proc., 48th int. conference on Association of Asphalt Paving Technologists 48th int. conference on Association of Asphalt Paving TechnologistsSuite I, St Paul, MN 55102,USA 1979 400 Selby Avenue * Design and construction of Asphalt Pavements JRMartin HAWallace McGraw Hill Book co * Improving the Performance of Bituminous Concrete Mix by Waste Plastic KKapil Soni Punjabi 2014 * Highway Engineering KKhanna PhD 1991 Standard Publishers Distributors 440 454 Delhi, India 7th edition * Effect of waste polymer modifier on the properties of bituminous concrete mixes TabrezalamSangita Khan DKSabin Sharma * The Durability Study of the Use of Modified Wa ste Plastic-Bitumen in Asphalt Concrete Mix Containing Reclaimed Asphalt Pavement AYamin I&aschuri