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.

scholarly journals Characteristics of Warm Mix Asphalt Incorporating Coarse Steel Slag Aggregates

2021 ◽  
Vol 11 (8) ◽  
pp. 3708
Author(s):  
Adham Mohammed Alnadish ◽  
Mohamad Yusri Aman ◽  
Herda Yati Binti Katman ◽  
Mohd Rasdan Ibrahim
Keyword(s):  
Environmental Sustainability ◽  
Prediction Models ◽  
Hot Mix Asphalt ◽  
Steel Slag ◽  
Warm Mix Asphalt ◽  
Asphalt Mixes ◽  
Toxic Emissions ◽  
Comparable Performance ◽  
Different Temperatures ◽  
Production Temperature

The major goal of sustainable practices is to preserve raw resources through the utilization of waste materials as an alternative to natural resources. Decreasing the temperature required to produce asphalt mixes contributes to environmental sustainability by reducing energy consumption and toxic emissions. In this study, warm mix asphalt incorporating coarse steel slag aggregates was investigated. Warm mix asphalt was produced at different temperatures lower than the control asphalt mixes (hot mix asphalt) by 10, 20, and 30 °C. The performances of the control and warm mix asphalt were assessed through laboratory tests examining stiffness modulus, dynamic creep, and moisture sensitivity. Furthermore, a response surface methodology (RSM) was conducted by means of DESIGN EXPERT 11 to develop prediction models for the performance of warm mix asphalt. The findings of this study illustrate that producing warm mix asphalt at a temperature 10 °C lower than that of hot mix asphalt exhibited the best results, compared to the other mixes. Additionally, the warm mix asphalt produced at 30 °C lower than the hot mix asphalt exhibited comparable performance to the hot mix asphalt. However, as the production temperature increases, the performance of the warm mix asphalt improves.

Field-aged asphalt binder performance evaluation for Evotherm warm mix asphalt: Comparisons with hot mix asphalt

2017 ◽  
Vol 156 ◽  
pp. 574-583 ◽  
Author(s):  
Shenghua Wu ◽  
Weiguang Zhang ◽  
Shihui Shen ◽  
Xiaojun Li ◽  
Balasingam Muhunthan ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Hot Mix Asphalt ◽  
Asphalt Binder ◽  
Warm Mix Asphalt ◽  
Aged Asphalt

scholarly journals EFFECT OF RH-WMA ADDITIVE ON ENGINEERING PROPERTIES OF BITUMEN PG-76/KESAN BAHAN TAMBAH RH-WMA KE ATAS SIFAT- SIFAT KEJURUTERAAN BITUMEN PG-76

2019 ◽  
Vol 81 (4) ◽  
Author(s):  
Gatot Rusbintardjo ◽  
Sitti Salmah Abdul Wahab ◽  
Faridah Hanim Khairuddin ◽  
Ahmad Nazrul Hakimi Ibrahim ◽  
Nur Izzi Md Yusoff ◽  
...  
Keyword(s):  
Contact Angle ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Warm Mix Asphalt ◽  
Molecular Structures ◽  
Engineering Properties ◽  
Morphological Properties ◽  
Modified Binders ◽  
Modified Binder

Pavement failure phenomena is normally caused by low quality of mixture materials, especially bitumen. The modification of bitumen is one of the alternatives to improve the performance of the material. Therefore, this study was conducted to investigate the performance of a polymer-modified binder (PG-76) with the addition of different percentages of Reduce Heat-Warm Mix Asphalt (RH-WMA) at 1, 2, 3, 4 and 5 % (by-weight of binder). Several testings such as penetration, softening point and ductility tests were conducted to determine the physical properties of PG-76 and RH-WMA modified binders. The molecular structures of the materials were analysed using Fourier transform infrared spectroscopy (FTIR) test while the contact angle test was conducted to investigate the type of binder’s surface. In addition, an optical microscopy test was carried out to determine the morphological properties of the modified binders. Results show that the PG-76’s hardness decreases with the increasing of RH-WMA percentage, but the ductility values are still within the specification. The FTIR test shows an increase of RH-WMA percentage does not provide a significant reaction of the binder and the original properties of the materials remain. The morphology test shows that all percentage of RH-WMA selected are well dispersed in bitumen PG-76. Based on the contact angle results, all the PG-76 and RH-WMA modified binders fall into hydrophobic category.

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.

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