Evaluation of Moisture Susceptibility of Asphalt Mixtures: Conventional and New Methods

2000 ◽  
Vol 1728 (1) ◽  
pp. 43-51 ◽  
Author(s):  
N. Khosla ◽  
Brian G. Birdsall ◽  
Sachiyo Kawaguchi
Keyword(s):  
Tensile Strength ◽  
Friction Angle ◽  
Hydrated Lime ◽  
Asphalt Mixtures ◽  
Degree Of Saturation ◽  
Phosphate Ester ◽  
Simple Method ◽  
Moisture Sensitivity ◽  
Moisture Susceptibility ◽  
New Apparatus

Evaluation of a mixture’s moisture sensitivity is currently the final step in the Superpave® volumetric process. This step is accomplished by using AASHTO T-283, which tolerates a range of values in the test variables of sample air voids and degree of saturation. The tensile strength ratios determined for the mixes in this study varied with the air void level and degree of saturation. Although the levels of conditioning were within the specifications for AASHTO T-283, test results both passed and failed the 80 percent criterion, depending on the severity of conditioning. An alternative to measuring indirect tensile strength is a test that evaluates a mixture’s fundamental material properties. A relatively simple test is proposed that measures the cohesion and friction angle for asphalt mixtures. In addition, the Superpave shear tester (SST) was incorporated as a tool in evaluating moisture sensitivity. The proposed axial test determined the cohesion and angle of friction of the mix. The friction angle remained constant for the conditioned and unconditioned samples. Hence, conditioning of the samples had practically no effect on the mixture’s internal friction. The cohesion of the mix decreased when the mix was subjected to conditioning. The reduction in cohesion was greater in the case of the Fountain aggregate, which is known to be highly moisture susceptible. The shear tests to failure performed on the SST confirmed the results of the new apparatus, which provides a simple method for determining a mixture’s cohesion. The loss of cohesion due to conditioning can be used to determine a mixture’s moisture susceptibility. The three antistrip additives used in this study were hydrated lime, a liquid amine, and a liquid phosphate ester.

scholarly journals Evaluations of Nano-Sized Hydrated Lime on the Moisture Susceptibility of Hot Mix Asphalt Mixtures

2012 ◽  
Vol 174-177 ◽  
pp. 82-90 ◽  
Author(s):  
Ju Nan Shen ◽  
Zhao Xing Xie ◽  
Fei Peng Xiao ◽  
Wen Zhong Fan
Keyword(s):  
Tensile Strength ◽  
Experimental Design ◽  
Hot Mix Asphalt ◽  
Hydrated Lime ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Moisture Resistance ◽  
Strength Ratio ◽  
Moisture Susceptibility ◽  
Indirect Tensile

The objective of this study was to evaluate the effect of nano-sized hydrated lime on the moisture susceptibility of the hot mix asphalt (HMA) mixtures in terms of three methodologies to introduce into the mixtures. The experimental design for this study included the utilizations of one binder source (PG 64-22), three aggregate sources and three different methods introducing the lime. A total of 12 types of HMA mixtures and 72 specimens were fabricated and tested in this study. The performed properties include indirect tensile strength (ITS), tensile strength ratio (TSR), flow, and toughness. The results indicated that the nano-sized lime exhibits better moisture resistance. Introducing process of the nano-sized lime will produce difference in moisture susceptibility.

scholarly journals Effect of Hydrated Lime on Moisture Susceptibility of Asphalt Mixtures

2019 ◽  
Vol 25 (3) ◽  
pp. 89-101
Author(s):  
Mohammed Qadir Ismael ◽  
Ahmed Hussein Ahmed
Keyword(s):  
Tensile Strength ◽  
Asphalt Binder ◽  
Maximum Size ◽  
Hydrated Lime ◽  
Asphalt Mixtures ◽  
Strength Ratio ◽  
Moisture Susceptibility ◽  
Damage Resistance ◽  
Limestone Dust ◽  
Two Parameters

Moisture induced damage can cause a progressive deterioration in the performance of asphalt pavement by the loss of adhesion between asphalt binder and aggregate surface and/or loss of cohesion within the binder in the presence of water. The objective of this paper is to improve the asphalt mixtures resistance to moisture by using hydrated lime as an anti-stripping additive. For this purpose, two types of asphalt binder were utilized; asphalt grades (40-50) and (60-70) with one type of aggregate of 19.0 mm aggregate nominal maximum size, and limestone dust as a mineral filler. Marshall method was adopted to find the optimum asphalt content. Essentially, two parameters were determined to evaluate the moisture susceptibility, namely: The Index of Retained Strength and the Tensile Strength Ratio. The hydrated lime was added by 1.0, 1.5, and 2.0 percentages (by weight of aggregate) using the saturated surface dry method. It was concluded that using hydrated lime will improve the moisture damage resistance. This was adopted as the value of tensile strength ratio increased by 24.50 % and 29.16% for AC (40-50) and AC (60-70) respectively, furthermore, the index of retained strength also increased by 14.28 % and 17.50 % for both asphalt grades. The optimum hydrated lime content founded to be 1.5 %.  

scholarly journals Effect of SBS Polymer and Anti-stripping Agents on the Moisture Susceptibility of Hot and Warm Mix Asphalt Mixtures

2017 ◽  
Vol 3 (10) ◽  
pp. 987 ◽  
Author(s):  
Hamed Omrani ◽  
Ali Reza Ghanizadeh ◽  
Amin Tanakizadeh
Keyword(s):  
Tensile Strength ◽  
Hydrated Lime ◽  
Warm Mix Asphalt ◽  
Primary Objective ◽  
Asphalt Mixtures ◽  
Strength Ratio ◽  
Test Results ◽  
Moisture Susceptibility ◽  
Modified Asphalt ◽  
Polymer Modified Asphalt

The primary objective of this study is exploring the moisture susceptibility of unmodified and SBS-modified hot and warm mix asphalt mixtures. To this end, two different WMA additives including Aspha-min and Sasobit were employed to fabricate WMA specimens. The moisture susceptibility of warm polymer modified asphalt (WPMA) mixes was evaluated using modified Lottman test at 25°C according to AASHTO standard (T 283). In addition, the effect of different percentages of hydrated lime (from 0% to 2%) and Zycosoil (from 0% to 0.1%) as anti-stripping additives on the moisture susceptibility of the mixtures was explored. Based on the ITS test results, WPMA prepared with Sasobit additive and polymer modified asphalt (PMA) mixes satisfied the desirable tensile strength ratio (TSR) (above 80%) but Aspha-min WPMA mixes had TSR lower than 80%.

Moisture susceptibility evaluation of asphalt mixtures containing Evonik, Zycotherm and hydrated lime

2018 ◽  
Vol 165 ◽  
pp. 958-965 ◽  
Author(s):  
Mahmoud Ameri ◽  
Mostafa Vamegh ◽  
Seyed Farhad Chavoshian Naeni ◽  
Mohammad Molayem
Keyword(s):  
Hydrated Lime ◽  
Asphalt Mixtures ◽  
Moisture Susceptibility ◽  
Susceptibility Evaluation

scholarly journals Investigation of Moisture Sensitivity and Conductivity Properties of Inductive Asphalt Mixtures Containing Steel Wool Fiber

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Seyed Mohsen Hosseinian ◽  
Vahid Najafi Moghaddam Gilani ◽  
Peyman Mehraban Joobani ◽  
Mahyar Arabani
Keyword(s):  
Electrical Conductivity ◽  
Tensile Strength ◽  
Electrical Resistivity ◽  
Asphalt Mixtures ◽  
Dynamic Resistance ◽  
Moisture Resistance ◽  
Steel Wool ◽  
Moisture Sensitivity ◽  
Optimal Amount ◽  
Marshall Stability

The construction of suitable roads in rainy areas has created problems in the construction process due to the low resistance of asphalt to moisture. To solve this problem, materials are commonly used that make mixtures resistant to moisture; however, these materials may reduce the dynamic resistance of asphalt. Therefore, materials should be used that, in addition to increasing the dynamic resistance, also increase the moisture resistance of asphalt mixtures. One of these materials used in this research is steel wool fiber (SWF), which in addition to creating conductive roads also could have a significant effect on moisture resistance. In this study, the impact of 2%, 4%, 6%, 8%, and 10% SWF on the Marshall stability and moisture sensitivity of mixtures was investigated using the Marshall stability and indirect tensile strength (ITS) tests, respectively. Moreover, using SWF as a conductive fiber, the conductivity properties of asphalt mixtures were explored to find the optimal amount of electrical conductivity. The results of the Marshall stability test indicated that by increasing SWF contents, the stability of mixtures increased, compared with the base sample, and greater amounts of 6% SWF resulted in the reduction of the Marshall stability. The results of ITS showed that modification of bitumen by SWF increased ITS and tensile strength ratio (TSR) amounts of mixtures. 6% SWF was the optimal amount for enhancing the resistance of asphalt mixtures to moisture sensitivity. The results of the electrical resistivity test showed that the resistivity had three phases: high resistivity, transit, and low resistivity. Mixtures containing less than 4% SWF illustrated an insulating behavior, with electrical resistivity greater than 7.62  ×  108  Ω . m . At the transit phase, the resistivity of mixtures had a sharp reduction from 7.62  ×  108  Ω . m to 6.17  ×  104  Ω . m . Finally, 8% SWF was known as the optimal content for the electrical conductivity of mixtures.

scholarly journals Advantages Of Filler And Surfactant Additive To Improve Moisture Sensitivity Of Hot Mix Asphalt Mixtures.

2021 ◽  
Vol 1202 (1) ◽  
pp. 012011
Author(s):  
Asres Simeneh ◽  
Alamrew ◽  
Konrad Mollenhauer
Keyword(s):  
Tensile Strength ◽  
Mineral Composition ◽  
Hydrated Lime ◽  
Moisture Sensitivity ◽  
Bituminous Mixtures ◽  
Asphalt Mix ◽  
Indirect Tensile ◽  
Surfactant Additive ◽  
Long Term Performance ◽  
Term Performance

Abstract This research investigated the effect of mineral composition of aggregate on moisture sensitivity of bituminous mixtures and explored the benefits of hydrated lime filler and Wetfix BE surfactant additive to improve the resistance of the mix against moisture sensitivity. Basalt, quartzite, and limestone aggregates were selected based on their different mineralogy and 70 -100 penetration graded bitumen binders used during the study. Four laboratory tests the rolling bottle, shaking abrasion, pull-off tensile strength and indirect tensile strength tests were applied to study the effects of aggregate minerals and benefits of hydrated lime and Wetfix BE. Statistical analysis using Two-way ANOVA test conducted for each test to check the outcome significance. Results from each test revealed that mineral composition of aggregate have significant effects on the moisture resistance performance of bituminous mixtures and hydrated lime filler and Wetfix BE surfactant additives have advantages to improve the performance of bituminous mixture against moisture sensitivity and improves the long-term performance of asphalt mix.

Model for predicting tensile strength of unsaturated cohesionless soils

2018 ◽  
Vol 55 (9) ◽  
pp. 1313-1333 ◽  
Author(s):  
Penghai Yin ◽  
Sai K. Vanapalli
Keyword(s):  
Tensile Strength ◽  
Characteristic Curve ◽  
Experimental Studies ◽  
Friction Angle ◽  
Matric Suction ◽  
Degree Of Saturation ◽  
Engineering Practice ◽  
Cohesionless Soils ◽  
Proposed Model ◽  
Earth Structures

The influence of tensile strength on the behaviour of cohesionless soils is typically ignored in geotechnical engineering practice. However, the tensile cracking and subsequent failure characteristics of earth structures, such as dams, slopes and embankments, are significantly influenced by the tensile strength. For this reason, a semi-empirical model is proposed for predicting the variation of the tensile strength of unsaturated cohesionless soils with the degree of saturation, using the soil-water characteristic curve (SWCC) as a tool. The proposed model is capable of predicting the tensile strength arising from matric suction and surface tension, which are related to saturated pores and to the air–water interface associated with water bridges around interparticle contacts in unsaturated pores, respectively. Information about (i) the matric suction (ua– uw), the capillary degree of saturation (Sc), and the residual degree of saturation (Sr) derived from the SWCC; (ii) the mean particle size (d50) and the coefficient of uniformity (Cu) from the grain-size distribution curve; (iii) the void ratio (e); and (iv) the friction angle ([Formula: see text]) at low normal stress level is required to employ this model. The proposed model is validated by comparing the prediction results with measured tensile strength of 10 different unsaturated cohesionless soils (including five sandy soils and five silty soils). The proposed model is promising for use in engineering practice applications as it only requires conventional soil properties, alleviating the need for cumbersome experimental studies for the determination of tensile strength of unsaturated cohesionless soils.

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