scholarly journals Evaluation of Using Natural Fillers to Improve Moisture Damage Resistance and the Use of Pull-Off Tensile Test in Determining Moisture Damage Resistance in Asphalt Mixture

2020 ◽  
Vol 10 (12) ◽  
pp. 4318 ◽  
Author(s):  
Kroekphon Rachabut ◽  
Preeda Chaturabong

Moisture is one of the critical failures affecting asphalt pavement. It has been recently found that moisture created by rainwater and undrained water deteriorate the bonding interface between asphalt mastic and aggregate. Using different mineral fillers can lead to different moisture resistance in the same mix design. Nowadays, waste natural materials allow agriculturists to receive more income by recycling in many industries. In this study, the researchers adopted bagasse and coconut peat grinding into very fine particle passing through the sieve number 200 (0.075 mm) to replace the mineral fillers. Although the indirect tensile strength (ITS) test is commonly used for evaluating the moisture damage resistance of hot-mix asphalt (HMA) in a laboratory, there are some shortcomings in using this test, such as costly, heavy and indirect equipment. Another potential test that is likely to be more advantageous than the ITS test for evaluating the moisture damage resistance is the pull-off tensile strength (POTS) test. However, it is typically measured on a concrete surface, and no results using an asphalt mixture have been reported. The objectives in this study were to investigate the effects of waste natural fillers in asphalt mixture on adhesive bonding caused by moisture, and to determine whether the POTS test is a potential method in measuring moisture damage resistance in a laboratory. Results showed that the tensile strength ratios (TSR) of asphalt mixture with bagasse and coconut peat fillers are approximately equivalent to those with mineral fillers. Results also showed that asphalt mixtures with bagasse and coconut peat fillers can effectively prevent the moisture damage resistance. In addition, with the preliminary result, it was found that the POTS test showed a very good R square (R2) for a relation of TSR with the ITS test. As a result, the POTS can be a valid tool of quantifying moisture damage resistance with better simulating to field behavior, lower cost of equipment, and light weight.

Author(s):  
Rabeea W. Bazuhair ◽  
Carl V. Pittman ◽  
Isaac L. Howard ◽  
Walter S. Jordan ◽  
James Michael Hemsley ◽  
...  

Asphalt mixes often have many ingredients that can interact with each other. When put into service, where there are multiple environmental effects, there are many interactions that need mixture testing. This paper’s objective was to evaluate laboratory conditioning protocols coupled with subsequent property measurements for their ability to detect damage of asphalt mixtures in the southeastern U.S. climate (or similar climates). The investigation’s focus is the property measurements themselves, and in particular how a given test can simultaneously assess multiple types of damage (i.e. oxidation, moisture damage, and freeze-thaw damage). While in service, mixtures can be damaged in multiple manners so laboratory conditioning protocols that expose specimens to multiple types of damage are needed as are test(s) that can detect these damages in a manner that can help assess performance during service. Four plant produced mixtures with all virgin ingredients were evaluated at intermediate temperatures with mixture and binder tests. The mixtures were well suited for such a comparison because they consisted of all virgin binder. Indirect tensile (IDT) strength did not relate to Cantabro Mass Loss (CML) or binder test results, which was concerning. Even more concerning was IDT’s inability to respond to laboratory conditioning protocols that considered multiple environmental effects (i.e., oxidation, moisture, and freeze-thaw). CML results related to binder properties and were able to reasonably detect multiple types of environmental effects. As such, Cantabro testing is recommended over tensile strength for intermediate temperature mixture property assessments related to non-load associated environmental effects.


CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 370-384
Author(s):  
Hossein Noorvand ◽  
Kamil Kaloush ◽  
Jose Medina ◽  
Shane Underwood

Asphalt aging is one of the main factors causing asphalt pavements deterioration. Previous studies reported on some aging benefits of asphalt rubber mixtures through laboratory evaluation. A field observation of various pavement sections of crumb rubber modified asphalt friction courses (ARFC) in the Phoenix, Arizona area indicated an interesting pattern of transverse/reflective cracking. These ARFC courses were placed several years ago on existing jointed plain concrete pavements for highway noise mitigation. Over the years, the shoulders had very noticeable and extensive cracking over the joints; however, the driving lanes of the pavement showed less cracking formation in severity and extent. The issue with this phenomenon is that widely adopted theories that stem from continuum mechanics of materials and layered mechanics of pavement systems cannot directly explain this phenomenon. One hypothesis could be that traffic loads continually manipulate the pavement over time, which causes some maltenes (oils and resins) compounds absorbed in the crumb rubber particles to migrate out leading to rejuvenation of the mastic in the asphalt mixture. To investigate the validity of such a hypothesis, an experimental laboratory testing was undertaken to condition samples with and without dynamic loads at high temperatures. This was followed by creep compliance and indirect tensile strength testing. The results showed the higher creep for samples aged with dynamic loading compared to those aged without loading. Higher creep compliance was attributed to higher flexibility of samples due to the rejuvenation of the maltenes. This was also supported by the higher fracture energy results obtained for samples conditioned with dynamic loading from indirect tensile strength testing.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7060
Author(s):  
Mohammad Alharthai ◽  
Qing Lu ◽  
Ahmed Elnihum ◽  
Asad Elmagarhe

This study investigates the substitution of conventional aggregate with a Florida washed shell in open-graded asphalt mixtures and evaluates the optimal substitution percentage in aggregate gradations of various nominal maximum aggregate sizes (NMASs) (i.e., 4.75, 9.5, and 12.5 mm). Laboratory experiments were performed on open-graded asphalt mixture specimens with the coarse aggregate of sizes between 2.36 and 12.5 mm being replaced by the Florida washed shell at various percentages (0, 15, 30, 45, and 100%). Specimen properties relevant to the performance of open-graded asphalt mixtures in the field were tested, evaluated, and compared. Specifically, a Marshall stability test, Cantabro test, indirect tensile strength test, air void content test, and permeability test were conducted to evaluate the strength, resistance to raveling, cracking resistance, void content, and permeability of open-graded asphalt mixtures. The results show that there is no significant difference in the Marshall stability and indirect tensile strength when the coarse aggregates are replaced with Florida washed shell. This study also found that the optimum percentages of Florida washed shell in open-graded asphalt mixture were 15, 30, and 45% for 12.5, 9.5, and 4.75 mm NMAS gradations, respectively.


2012 ◽  
Vol 509 ◽  
pp. 149-154
Author(s):  
Jun Xie ◽  
Jun Cai ◽  
Shao Peng Wu ◽  
Ling Pang

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.


2010 ◽  
Vol 168-170 ◽  
pp. 2654-2657
Author(s):  
Xiao Jun Li ◽  
Li Hua Jiang ◽  
Yun Xian Wang

In this paper, a new Indirect tensile tester (IDT) which can be cooperated with Industrial Computered Tomography (IDT) is developed. The new tester uses a set of sliders to transfer the vertical stress to hoop stress which applied to a hollow cylindrical sample. The micro-crack will be appeared and propagated in the weakest direction of hollow cylindrical sample with the increase of vertical stress and tensile strength can calculated with the maximum vertical stress. Due to the existence of central slider, the stress state of hollow cylindrical sample will be kept even after unloading and the mixture sample would not have recovery when it is moved for scanning with ICT. The test results show that the combination of the developed ICT with IDT will help obtain more useful information on understanding the nature of asphalt concrete with different tensile damage stages.


2011 ◽  
Vol 255-260 ◽  
pp. 3432-3436
Author(s):  
Xian Yuan Tang ◽  
Jie Xiao

This paper systematically elaborates the impact upon performance of emulsion asphalt cold reclaimed asphalt mixture by different RAP contents, through a series of testing on six cold reclaimed asphalt mixtures with various RAP contents, such as single axle compression test, 15°C indirect tensile strength (ITS) test, 40°C rutting test and -10°C low-temperature bending beam test. Testing results indicate that 15°C ITS decreases from around 0.75 MPa to 0.58 MPa with the RAP content of mixture increasing from 0% to 100%. 40°C dynamic stabilities reduce considerably from around 19,000 time/mm of 0% RAP mixture to 3,600 time/mm of 100% RAP mixture. -10°C failure strains only change from 1500με to 2000με.


1997 ◽  
Vol 1590 (1) ◽  
pp. 108-117 ◽  
Author(s):  
Richard P. Izzo ◽  
Joe W. Button ◽  
Maghsoud Tahmoressi

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.


2016 ◽  
Vol 700 ◽  
pp. 227-237 ◽  
Author(s):  
Siti Nur Amiera Jeffry ◽  
Ramadhansyah Putra Jaya ◽  
Norhafizah Manap ◽  
Nurfatin Aqeela Miron ◽  
Norhidayah Abdul Hassan

Significant quantities of coconut shell (CS), a by-product of agriculture, can be used as an artificial source of coarse aggregates. In this study, four CSs were used as coarse aggregates replacement in asphalt concrete with 0%, 10%, 20%, 30%, and 40% weight volumes. The particle sizes of the CSs used as main coarse aggregates range from 5 mm to 20 mm. The Marshall Stability test shows that the optimum bitumen content for asphalt mixtures is 5.1%. The engineering properties investigated include the volumetric, dynamic creep, indirect tensile strength, and resilient modulus. Test results show that stability decreases with increasing CS content because of high water absorption. Considering that CSs absorb bitumen, a further detailed investigation is needed to assess the performance of modified bitumen on mixture. Furthermore, the use of CSs as coarse aggregates in asphalt concrete help increase the resilient modulus, stiffness, and indirect tensile strength up to 30%. Generally, a 10% replacement of coarse aggregates with CSs is the optimal limit.


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