scholarly journals Restriction of RAP% in HMA Based on Aggregate Gradation and Binder Properties

CivilEng ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 811-822
Author(s):  
Bharath Gottumukkala ◽  
Sudhakar Reddy Kusam ◽  
Vivek Tandon ◽  
Amaranatha Reddy Muppireddy ◽  
Ramya Sri Mullapudi
Keyword(s):  
Hot Mix Asphalt ◽  
Asphalt Pavement ◽  
Asphalt Binders ◽  
Recycled Asphalt ◽  
Aggregate Gradation ◽  
Naturally Occurring ◽  
Milling Method ◽  
Pavement Construction ◽  
Point G

The use of recycled asphalt pavement (RAP) in pavement construction reduces the project cost and helps in conserving the naturally occurring aggregates. To incorporate RAP in hot mix asphalt, it is vital to know the amount and quality of the reclaimed binder. Three new asphalt binders were selected for this investigation. RAP material from one source was blended in different proportions with VG-10 and VG-30. Penetration, softening point, G */sin δ, G * sin δ and binder fatigue life Nf (from Linear Amplitude Sweep test) values of different blends were compared. The milled RAP aggregate gradation varied from source to source due to factors such as the gradation of the mix used in the existing layer, milling method and processing of RAP material. This variability controls the use of higher proportions of RAP in new mixes. To investigate the effect of RAP gradation on the proportion of RAP that can be used in the new mix, RAP sources with different gradation (three dense and two gap gradations) were selected. The proportion of RAP that can be used for preparing mixes with these gradations varied significantly with the source of RAP, and the target gradation. In most cases, it was found that allowable RAP percentages are smaller for the gap gradations compared to those permitted for dense gradations. The proportion of RAP in a mix can be increased by selecting an appropriate gradation for a RAP source or by using a suitable RAP source for a given gradation.

scholarly journals Performance Evaluation of Hot Mix Asphalt with Different Proportions of RAP Content

2018 ◽  
Vol 34 ◽  
pp. 01026
Author(s):  
Ahmad Kamil Arshad ◽  
Haryati Awang ◽  
Ekarizan Shaffie ◽  
Wardati Hashim ◽  
Zanariah Abd Rahman
Keyword(s):  
Hot Mix Asphalt ◽  
Resilient Modulus ◽  
Design Method ◽  
Asphalt Pavement ◽  
Cost Savings ◽  
Volumetric Analysis ◽  
Public Works ◽  
Asphalt Binders ◽  
Moisture Susceptibility ◽  
Asphalt Mixes

Reclaimed Asphalt Pavement (RAP) is old asphalt pavement that has been removed from a road by milling or full depth removal. The use of RAP in hot mix asphalt (HMA) eliminates the need to dispose old asphalt pavements and conserves asphalt binders and aggregates, resulting in significant cost savings and benefits to society. This paper presents a study on HMA with different RAP proportions carried out to evaluate the volumetric properties and performance of asphalt mixes containing different proportions of RAP. Marshall Mix Design Method was used to produce control mix (0% RAP) and asphalt mixes containing 15% RAP, 25% RAP and 35% RAP in accordance with Specifications for Road Works of Public Works Department, Malaysia for AC14 dense graded asphalt gradation. Volumetric analysis was performed to ensure that the result is compliance with specification requirements. The resilient modulus test was performed to measure the stiffness of the mixes while the Modified Lottman test was conducted to evaluate the moisture susceptibility of these mixes. The Hamburg wheel tracking test was used to evaluate the rutting performance of these mixes. The results obtained showed that there were no substantial difference in Marshall Properties, moisture susceptibility, resilient modulus and rutting resistance between asphalt mixes with RAP and the control mix. The test results indicated that recycled mixes performed as good as the performance of conventional HMA in terms of moisture susceptibility and resilient modulus. It is recommended that further research be carried out for asphalt mixes containing more than 35% RAP material.

Evaluation of Local Asphalt Binders under Superpave Specification

2012 ◽  
Vol 178-181 ◽  
pp. 1509-1512 ◽  
Author(s):  
Hussain Arshad ◽  
Yan Jun Qiu
Keyword(s):  
High Temperatures ◽  
Flexible Pavements ◽  
Asphalt Binder ◽  
Flexible Pavement ◽  
Asphalt Binders ◽  
Grading System ◽  
Empirical Tests ◽  
Heavy Loads ◽  
Pavement Construction

Premature rutting due to high temperatures and heavy loads has been a major distress on flexible pavements in Pakistan. One of the main causes of this early rutting is the available asphalt binders, which are still graded by using penetration grading system. The penetration grading system is based on empirical tests and does not link with performance. To improve the quality of the flexible pavement and to avoid the premature rutting the performance based testings were conducting in laboratory. This study evaluated performance graded (PG) binders for use in pavement construction in the country. Five different penetration graded asphalt binder, typically available in the country were graded according to PG system. The performance grades (PG) for all binders were determined based on DSR and BBR results. The two same penetration grades ARL60/70 and NRL 60/70 have different PG grades. The two different penetration grades ARL60/70 and NRL 80/100 have same PG grade. The results show that the local binders are very soft due to which they performed poorly at high temperatures and prone to severe rutting.

scholarly journals Mechanical performance assessment of half warm recycled asphalt mixes containing up to 100 % RAP

2017 ◽  
Vol 7 (080) ◽  
pp. 129 ◽  
Author(s):  
J. M. Lizárraga ◽  
A. Jiménez del Barco-Carrión ◽  
A. Ramírez ◽  
P. Díaz ◽  
F. Moreno-Navarro ◽  
...  
Keyword(s):  
Hot Mix Asphalt ◽  
Mechanical Performance ◽  
Asphalt Pavement ◽  
Reclaimed Asphalt Pavement ◽  
Recycled Asphalt ◽  
Stiffness Modulus ◽  
Asphalt Mixes ◽  
Reclaimed Asphalt ◽  
Second Stage ◽  
Asphalt Content

The use of Half Warm Mixes with high Reclaimed Asphalt content (HWMRA) has the potential to generate significant environmental advantages such as the reduction in consumption of natural resources and the emission of gases into the atmosphere. This paper therefore focuses on demonstrating the viability of using these types of mixes in wearing courses. For this purpose, an HWMRA with 70 % and 100 % Reclaimed Asphalt Pavement (RAP) and emulsion were designed in the laboratory. The performance of the mixes was then assessed and compared with that of conventional Hot Mix Asphalt. In a second stage, the mixes were manufactured in-plant, and laid and compacted in an Accelerated Pavement Test track. The cores were then extracted and tested for stiffness modulus and resistance to fatigue. The results from the tests conducted with both the laboratory specimens and the cores showed that the performance of HWMRA is comparable to that of HMA. These findings encourage greater confidence in promoting the use of these types of sustainable asphalt mixes.

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