scholarly journals Examining the Effect of Dry Resin on Moisture Sensitivity of Asphaltic Mixtures

2018 ◽  
Vol 4 (7) ◽  
pp. 1714 ◽  
Author(s):  
Morteza Ghaffari Jajin ◽  
G. Hosein Hamedi
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Hydrated Lime ◽  
Moisture Damage ◽  
Asphalt Mixtures ◽  
Polymer Additive ◽  
Moisture Sensitivity ◽  
Indirect Tensile ◽  
Effect Of Moisture ◽  
Moisture Resistant

Moisture damage in asphaltic mixtures is defined by the loss of durability and resistance caused by the effect of moisture. The most common way to improve moisture damage in asphaltic mixtures is to use anti-strip additives. This study tended to use dry resin polymer additive to make a moisture-resistant asphaltic mixture. Two types of aggregate indicating different sensitivities against moisture were studied. In order to compare the effect of this material with other anti-strip additives, this study evaluated the effect of hydrated lime on reducing moisture damage and comparing its effect with dry resin polymer additive. The effect of these materials was evaluated by mechanical and thermodynamic concepts using indirect tensile ratio and surface free energy. The results indicated that dry resin polymer used in this study increased alkaline content and reduced acidic content of bituminous surface free energy, resulting in more adhesion between acidic aggregates which are more sensitive to resistance. It also improved bitumen-aggregate adhesion and reduced strip rate. Moreover, hydrated lime as an aggregate anti-strip agent and dry resin polymer as a bituminous modifier significantly increased the resistance of warm asphalt mixtures against moisture. The results of this study show that dry resin polymer can be used as an anti-strip agent instead of hydrated lime with operational problems.

scholarly journals Investigating the Effect of Metal Nanomaterials on the Moisture Sensitivity Process of Asphalt Mixes

2020 ◽  
Author(s):  
Iraj Bargegol ◽  
Farhad Sakanlou ◽  
Mohsen Sohrabi ◽  
Gholam Hossein Hamedi
Keyword(s):  
Free Energy ◽  
Cyclic Loading ◽  
Resilient Modulus ◽  
Moisture Damage ◽  
Mechanical Tests ◽  
Destructive Effect ◽  
Moisture Sensitivity ◽  
Asphalt Mixes ◽  
Indirect Tensile ◽  
Sensitivity Indicator

One of the most common damages in asphalt mixes is the destructive effect of moisture on the binder cohesion and binder–aggregate adhesion which is called moisture damage. There are various methods to improve adhesion and reduce moisture damage in asphalt mixes. The most common of them is using an appropriate additive for binder modification. Accordingly, the current research was conducted to investigate the effect of two nanomaterials (Nano CuO, and Nano SnO2) in 2 different percentages on 2 types of aggregates (granite and limestone) and a type of base binder. In order to investigate the effect of nanomaterials, indirect tensile cyclic loading (the same as resilient modulus test) in dry and wet conditions and surface free energy (SFE) method were used. The moisture sensitivity indicator which shows stripping percentage of aggregate surface in loading cycles using SFE results and indirect tensile cyclic loading, has been considered as the moisture sensitivity indicator in this research. Results of mechanical tests used in this research show that nanomaterials have significantly increased asphalt mixes strength in comparison to control specimens. Results obtained from SFE method show that nanomaterials increase the cohesion free energy; this change causes a reduction in the possibility of failure in binder membrane. Additionally, nanoparticles have increased and reduced basic component and acidic component of SFE, respectively. This leads to improvement of their adhesion with acidic aggregates, which is sensitive to moisture damage.

scholarly journals Improving the Moisture Sensitivity of Asphalt Mixtures by Simultaneous Modification of Asphalt Binder and Aggregates with Carbon Nanofiber and Carbon Nanotube

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Mohammad Nikookar ◽  
Mojtaba Bagheri Movahhed ◽  
Jalal Ayoubinejad ◽  
Vahid Najafi Moghaddam Gilani ◽  
Seyed Mohsen Hosseinian
Keyword(s):  
Tensile Strength ◽  
Free Energy ◽  
Carbon Nanotube ◽  
Carbon Nanofiber ◽  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Moisture Sensitivity ◽  
Tensile Strength Test ◽  
Indirect Tensile

Moisture sensitivity of asphalt mixtures may cause damage due to cohesion in asphalt binder membrane and adhesion between aggregate and asphalt binder that result in considerable damage to the pavements. Therefore, by determining the adhesion quality in a modified aggregate-asphalt binder system, one can choose the suitable material compositions to decrease the moisture sensitivity of mixtures. In this study, the effects of modified asphalt binder with carbon nanofiber and modified aggregates with carbon nanotube on the moisture sensitivity of asphalt mixtures were simultaneously explored. For investigating the moisture sensitivity, the indirect tensile strength test and surface free energy concept were implemented. The results of the indirect tensile strength test revealed that modification of asphalt binder and aggregates with carbon nanofiber and carbon nanotube, respectively, increased the indirect tensile strength and tensile strength ratio values of mixtures. The results of surface free energy indicated that using carbon nanofiber and carbon nanotube enhanced the adhesion free energy of the aggregate-asphalt binder system. Moreover, utilizing carbon nanofiber to modify asphalt binder enhanced the cohesion free energy values in the asphalt binder membrane. Also, carbon nanofiber and carbon nanotube brought detachment energy of the system toward zero, indicating less desire for the mixtures to be stripped. Generally, investigations performed by the two methods showed that covering aggregates by carbon nanotube as well as utilizing carbon nanofiber as an asphalt binder modifier had a positive impact on decreasing moisture sensitivity of asphalt mixtures.

scholarly journals Experimental Investigation of Moisture Sensitivity and Damage Evolution of Porous Asphalt Mixtures

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7151
Author(s):  
Xinyu Hu ◽  
Xiaowei Wang ◽  
Nanxiang Zheng ◽  
Qiang Li ◽  
Jinyue Shi
Keyword(s):  
Fatigue Life ◽  
Fatigue Test ◽  
Damage Evolution ◽  
Moisture Damage ◽  
Exponential Model ◽  
Asphalt Mixtures ◽  
Moisture Sensitivity ◽  
Porous Asphalt ◽  
Dry Conditions ◽  
Indirect Tensile

Porous asphalt (PA) mixtures are designed with a high air void (AV) (i.e., 18~22%) content allowing rainwater to infiltrate into their internal structures. Therefore, PA mixtures are more sensitive to moisture damage than traditional densely graded asphalt mixtures. However, the moisture damage evolution of PA mixtures is still unclear. The objective of this study was to investigate the moisture damage evolution and durability damage evolution of PA mixtures. The indirect tensile test (ITT), ITT fatigue test, and Cantabro loss test were used to evaluate the moisture sensitivity and durability of PA mixtures, and a staged ITT fatigue test was developed to investigate the damage evolutions under dry and wet conditions. Indirect tensile strength (ITS), fatigue life, indirect tensile resilience modulus (E), and durability decreased with the increment of moisture damage and loading cycles. The fatigue life is more sensitive to the moisture damage. The largest decrements in ITS and E were found in the first 3000 loading cycles, and PA mixtures tended to fail when the decrement exceeded 60%. Damage factors based on the ITS and E are proposed to predict the loading history of PA mixtures. The durability damage evolution and damage factors could fit an exponential model under dry conditions. Moisture had a significant influence and an acceleration function on the moisture damage evolution and durability damage evolution of PA mixtures.

Surface free energy method for evaluating the effects of anti-stripping agents on the moisture damage to asphalt mixtures

2020 ◽  
Vol 34 (18) ◽  
pp. 1947-1970
Author(s):  
Wenzhen Wang ◽  
Aiqin Shen ◽  
Xiaolong Yang ◽  
Yinchuan Guo ◽  
Tianyuan Zhao
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Energy Method ◽  
Moisture Damage ◽  
Asphalt Mixtures

scholarly journals The Effects of Nano Bentonite and Fatty Arbocel on Improving the Behavior of Warm Mixture Asphalt against Moisture Damage and Rutting

2020 ◽  
Vol 6 (5) ◽  
pp. 877-888
Author(s):  
Sepehr Saedi ◽  
Seref Oruc
Keyword(s):  
Moisture Damage ◽  
Asphalt Mixtures ◽  
Maintenance Cost ◽  
Permanent Displacement ◽  
Moisture Sensitivity ◽  
Asphalt Cement ◽  
Dynamic Creep ◽  
Indirect Tensile ◽  
Reduce Energy Consumption ◽  
Low Performance

The use of warm mix asphalt (WMA) technology has increased dramatically in recent years to protect the environment and reduce energy consumption. Despite numerous advantages, WMAs are less commonly used as a result of their lower performance in comparison to HMAs. One of the main reasons for the low performance of WMAs is their high moisture sensitivity. In recent decades, bitumen modifiers have been used to improve the performance of asphalt mixtures. One of the additives that has recently been used to modify the characteristics of bitumen, is bentonite. The grade of asphalt cement used in this study is PG 64 -22 and the Bitumen is modified with 1, 3, 5 and 7% nano bentonite. Also, 0.3% fatty Arbocel has been used for the preparation of WMA. Indirect tensile strength (ITS) test and Nicholson stripping test are used to determine moisture sensitivity and dynamic creep test and LCPC are also used to evaluate the rutting potential. The results indicate that, increasing the percentage of nano bentonite and applying 0.3% of fatty Arbocel improves the resistance of mixture against moisture damage. Also it was found that increasing the mixture hardness decreases the permanent displacement and rutting potential of WMAs. So, it is suggested that the consumption of these additives increases WMA’s lifetime and decreases its maintenance cost.

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.

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