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 Indicadores do desempenho de misturas asfálticas determinados através do ensaio de compressão diametral

TRANSPORTES ◽  
2008 ◽  
Vol 16 (1) ◽  
Author(s):  
Lélio Antônio Teixeira Brito ◽  
Jorge Augusto Pereira Ceratti ◽  
Daniel Ramos Victorino
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fatigue Life ◽  
Cyclic Loading ◽  
Tensile Test ◽  
Resilient Modulus ◽  
Phase Lag ◽  
Asphalt Mixes ◽  
Indirect Tensile Test ◽  
Indirect Tensile

<p>Os ensaios de compressão diametral são amplamente usados no Brasil para determinação das propriedades mecânicas de misturas asfálticas, tanto através de ensaios monotônicos para determinação da resistência à tração, quanto sob carregamentos cíclicos para determinação do módulo de resiliência e da vida de fadiga. Este trabalho teve como objetivo mostrar que com instrumentação adequada destes ensaios, indicadores adicionais àqueles usualmente determinados podem ser obtidos. A energia mobilizada durante o ensaio de resistência à tração, bem como o monitoramento da rigidez ao longo do ensaio de fadiga e a defasagem medida entre o pulso de carga e o deslocamento no ensaio de módulo de resiliência, mostram-se promissores para este propósito.</p><p><em><strong>Abstract</strong> Indirect tensile test (IDT) are broadly used in Brazil for the assessment of mechanical properties of asphalt mixes, not only under monotonic loading to determine the tensile strength, but also under cyclic loading to determine resilient modulus and fatigue life. This study tries to demonstrate that with adequate instrumentation of these tests, additional indicators to those usually determined are possible to be obtained. The mobilized energy during the IDT test, as well as the monitoring of the stiffness during the fatigue test and the phase lag measured between load and displacement pulses in the resilient modulus test are promising for this purpose. </em></p>

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.

Surface Free Energy to Identify Moisture Sensitivity of Materials for Asphalt Mixes

2007 ◽  
Vol 2001 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Amit Bhasin ◽  
Dallas N. Little ◽  
Kamilla L. Vasconcelos ◽  
Eyad Masad
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Moisture Sensitivity ◽  
Asphalt Mixes

scholarly journals Evaluating the Surface Free Energy and Moisture Sensitivity of Warm Mix Asphalt Binders Using Dynamic Contact Angle

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Muhammad Rafiq Kakar ◽  
Meor Othman Hamzah ◽  
Mohammad Nishat Akhtar ◽  
Junita Mohamad Saleh
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Hot Mix Asphalt ◽  
Asphalt Binder ◽  
Moisture Damage ◽  
Warm Mix Asphalt ◽  
Work Of Adhesion ◽  
Moisture Sensitivity ◽  
Modified Binders ◽  
Production Temperature

From the environmental conservation perspective, warm mix asphalt is more preferable compared to hot mix asphalt. This is because warm mix asphalt can be produced and paved in the temperature range 20–40°C lower than its equivalent hot mix asphalt. In terms of cost-effectiveness, warm mix asphalt can significantly improve the mixture workability at a lower temperature and thus reduce greenhouse gas emissions, to be environment friendly. However, the concern, which is challenging to warm mix asphalt, is its susceptibility to moisture damage due to its reduced production temperature. This may cause adhesive failure, which could eventually result in stripping of the asphalt binder from the aggregates. This research highlights the significance of Cecabase warm mix additive to lower the production temperature of warm mix asphalt and improvise the asphalt binder adhesion properties with aggregate. The binders used in the preparation of the test specimen were PG-64 and PG-76. The contact angle values were measured by using the dynamic Wilhelmy plate device. The surface free energy of Cecabase-modified binders was then computed by developing a dedicated algorithm using the C++ program. The analytical measurements such as the spreadability coefficient, work of adhesion, and compatibility ratio were used to analyze the results. The results inferred that the Cecabase improved the spreadability of the asphalt binder over limestone compared to the granite aggregate substrate. Nevertheless, the Cecabase-modified binders improved the work of adhesion. In terms of moisture sensitivity, it is also evident from the compatibility ratio indicator that, unlike granite aggregates, the limestone aggregates were less susceptible to moisture damage.

Moisture Sensitivity of Bituminous Mixtures with Compound Fly Ash Modifier

2012 ◽  
Vol 509 ◽  
pp. 149-154
Author(s):  
Jun Xie ◽  
Jun Cai ◽  
Shao Peng Wu ◽  
Ling Pang
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Fly Ash ◽  
Moisture Damage ◽  
Moisture Sensitivity ◽  
Bituminous Mixtures ◽  
Primary Object ◽  
New Type ◽  
Indirect Tensile ◽  
Short Span

Bitumen pavement suffers from moisture damage mainly due to loss of durability and stability in a short span of service life. Filler is known to be capable of increasing the stiffness of bitumen binder, contributing to improvement of moisture sensitivity of bitumen mixture. In this paper a new type of filler named 'Compound Fly Ash Modifier' (CFAM) was introduced in order to enhance the bond strength between acidic aggregate with bitumen. The primary object is to determine the effect of CFAM on the moisture sensitivity of bitumen mixtures prepared by gneiss and granite respectively, which are termed acidic aggregate. Modified Lottman test and fatigue test were conducted. The results show that CFAM improves the resistance of mixes to moisture damage in the increase in indirect tensile strength and the extension of fatigue life. Finally the mechanism of modified effects for CFAM is discussed.

Comparison of Coarse Matrix High Binder and Dense-Graded Hot-Mix Asphalt

1997 ◽  
Vol 1590 (1) ◽  
pp. 108-117 ◽  
Author(s):  
Richard P. Izzo ◽  
Joe W. Button ◽  
Maghsoud Tahmoressi
Keyword(s):  
Tensile Strength ◽  
Creep Test ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Moisture Damage ◽  
Static Creep ◽  
Indirect Tensile ◽  
Effects Of Aging ◽  
Static Creep Test

Coarse matrix high binder (CMHB) is a gap-graded hot mix consisting of a large proportion of coarse aggregate with an asphalt binder-filler mastic. CMHB and dense-graded mixtures were compared in terms of their resistance to rutting (permanent deformation), moisture damage, aging, and water permeability. A static creep test was performed to evaluate relative rutting susceptibility. Moisture damage was assessed with the tensile strength ratio (TSR) and a boiling-water test. The effects of aging were evaluated with indirect tensile strength and resilient modulus testing. Penetration and complex shear modulus ( G*) of the recovered, aged asphalt were measured. Permeability was determined with Darcy's Law for flow through saturated, porous media. The static creep test did not indicate that CMHB mixtures were consistently more resistant to rutting in comparison with dense-graded mixtures. CMHB mixtures were found to be more resistant to moisture damage, which was indicated by higher TSR values and less visible stripping than corresponding dense-graded mixtures. The dense-graded mixtures exhibited higher resilient moduli and indirect tensile strengths after short-term and long-term aging. Penetration of binder extracted from aged CMHB mixtures was greater than that from dense-graded mixtures. Binder extracted from aged dense-graded mixtures exhibited higher G* values. The permeability of CMHB mixtures was greater than that of the dense-graded mixtures with comparable air voids.

A Comparative Study of Anti-Stripping Additives in Porous Asphalt Mixtures

2014 ◽  
Vol 70 (7) ◽  
Author(s):  
Mohamad Yusri Aman ◽  
Zulkurnain Shahadan ◽  
Mohd Zaime Mat Noh
Keyword(s):  
Asphalt Mixtures ◽  
Cohesive Failure ◽  
Moisture Sensitivity ◽  
Asphalt Mixes ◽  
Air Voids ◽  
Porous Asphalt ◽  
Coefficient Of Permeability ◽  
Indirect Tensile ◽  
Aashto T283 ◽  
Quarry Dust

Presence of water in porous asphalt mixtures detrimentally affected the bonding between binder-aggregate interface and cohesive failure within the binder-filler mastic, making them prone to stripping which contribute to the performance and durability. This paper presents the effect of anti-stripping additives in porous asphalt mixes. In this study, the Marshall specimens were prepared using quarry dust, ordinary Portland Cement (OPC) and Pavement Modifier (PMD) as filler then mixed with 60/70 penetration grade bitumen. The specimens were measured for air voids content and coefficient of permeability and subsequently tested using indirect tensile and Cantabro tests. The moisture sensitivity of porous asphalt was determined based on the ratio of dry and conditioned specimens according to AASHTO T283. The specimens prepared with PMD showed lower air voids content, hence decrease the permeability to give a higher tensile strength and lower abrasion loss compared to specimens prepared with OPC and quarry dust. Based on the results, the PMD filler has a great potential to improve resistance to moisture damage compared to mixes with OPC and specimens prepared with quarry dust fillers.

scholarly journals Influence of Polymeric Coating the Aggregate Surface on Moisture Damage of Hot Mix Asphalt

2020 ◽  
Author(s):  
Mojtaba Khodadadi ◽  
Alireza Azarhoosh ◽  
Ali Khodaii
Keyword(s):  
Tensile Strength ◽  
Polyethylene Terephthalate ◽  
Hot Mix Asphalt ◽  
Resilient Modulus ◽  
Asphalt Binder ◽  
Moisture Damage ◽  
Indirect Tensile Strength ◽  
Polymeric Coating ◽  
Moisture Susceptibility ◽  
Indirect Tensile

Moisture damage is one of the common causes of asphalt pavement failure in moisture presence. One of the convenient approaches to decreasing moisture sensitivity in hot-mix asphalt is coating the aggregate surface with a suitable agent. In this study, the effects of polyethylene terephthalate on moisture damage of asphalt mixtures were evaluated by applying indirect tensile strength and resilient modulus tests. The asphalt specimens were prepared with two types of aggregates (granite and limestone) and neat asphalt binder of 60/70 penetration grade. The results showed that the ratio of wet/dry values of indirect tensile strength and resilient modulus for mixtures containing limestone was higher than those of the samples with granite aggregate. Furthermore, the results of the laboratory tests indicate that polyethylene terephthalate improves resistance to moisture susceptibility. Because polyethylene terephthalate increases the wettability of asphalt binder over the aggregate and the adhesion between the asphalt binder and aggregate, especially in the mixtures containing acidic (granite) aggregate prone to moisture damage.

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