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

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.

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7151
Author(s):  
Xinyu Hu ◽  
Xiaowei Wang ◽  
Nanxiang Zheng ◽  
Qiang Li ◽  
Jinyue Shi

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.


2012 ◽  
Vol 486 ◽  
pp. 378-383 ◽  
Author(s):  
Che Wan Che Norazman ◽  
Ramadhansyah Putra Jaya ◽  
Meor Othman Hamzah

Oven ageing is a set of procedure to simulate the accelerated effects of ageing on pavements structures. In this study, the effect of long-term oven ageing on porous asphalt mixture made with SBS modified binder was investigated. The resilient modulus, water permeability and air voids test results were the performance indicators used to evaluate the effects of ageing. The test results showed that, the resilient modulus of long term aged specimens was higher than those of unaged specimens. From the permeability test results, unaged SBS mixes exhibit lower coefficient permeability compared to the corresponding long-term oven age specimens. Most likely, ageing caused binder hardening, making the mix more difficult to compact and hence exhibited more continuous voids which in turn lead to higher permeability. In addition, the coefficient of permeability decreases as the binder content increased.


2012 ◽  
Vol 204-208 ◽  
pp. 3934-3937 ◽  
Author(s):  
Bao Yang Yu ◽  
Yu Wang ◽  
Min Jiang Zhang

The objectives of this paper are to characterize the mechanical properties of porous asphalt pavement mixtures containing RAP and a WMA additive using Super pave gyratory compactor and dynamic modulus testing. Four types of asphalt mixtures were evaluated in this study. This study evaluated compaction energy index, permeability, indirect tensile strength, and dynamic modulus for all types of porous asphalt mixtures. All of the asphalt mixtures meet the typical minimum coefficient of permeability in this study. In addition, only a slight decrease in was found when WMA additive was added to the porous asphalt mixture containing RAP. For indirect tensile strength testing, WMA containing RAP was found to have the highest tensile strength among all of the mixtures tested.


Author(s):  
Iraj Bargegol ◽  
Farhad Sakanlou ◽  
Mohsen Sohrabi ◽  
Gholam Hossein Hamedi

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.


2009 ◽  
Vol 620-622 ◽  
pp. 347-250 ◽  
Author(s):  
Ting Wei Cao ◽  
Shao Peng Wu ◽  
Ming Yu Chen ◽  
Jun Tao Lin

Porous asphalt is one of the most functional structures for the surface layer of asphalt pavement, which has already shown excellent noise reduction property for its 20% air voids in the structure. However, mechanical degradation is also monitored because of the high air voids, for example, permanent deformation in high service temperature and cracking in low service temperature. The Tafpack Super (TPS) additive was used in this study and expected to improve the resistance to permanent deformation and low-temperature cracking of porous asphalt mixture. Unconfined static uniaxial creep test and three-point bending test were conducted to study the effects of TPS additive on the permanent deformation and anti-cracking property of porous asphalt mixture, respectively. Experimental results showed that the TPS additive decreased the creep deformation and increased the creep stiffness modulus in uniaxial creep test. TPS additive had little effect on the brittleness temperature porous asphalt mixtures as shown in three-point bending testing. However, the flexural strength-strain response curve indicated that with the increase of TPS additive, porous asphalt mixtures exhibited better resistance to cracking. Porous asphalt mixtures with TPS additive indicate excellent temperature susceptibility and can be applied to a wider field of road engineering.


Author(s):  
Mohsen Sohrabi ◽  
Hamid Shirmohammadi ◽  
Gholam Hossein Hamedi

The adhesion between aggregate and asphalt binder in dry conditions, and the amount of its reduction in wet conditions are amongst fundamental indicators that moisture sensitivity amount of asphalt mixtures is dependent to. Among different methods to increase adhesion, modification of aggregates surface with anti-stripping materials is known as an effective method. Therefore, the effect of covering aggregates surface with micronized calcium carbonate as a proper and inexpensive anti-stripping material was investigated. Accordingly, in order to evaluate mixes, first, mechanical methods were used, and then thermodynamic methods were employed to determine the mechanism of the effect of calcium carbonate on increasing asphalt mix resistance to moisture damage. In order to conduct this research, three types of aggregates including limestone, granite, and quartzite, for their different degrees of hydrophilic, and two types of asphalt binder 60–70 and 85–100 were used to produce mixtures. Results obtained by mechanical methods show that modification of aggregates surface causes an increase in the tensile strength ratio (TSR) in the samples made by both two types of asphalt binder. In addition, results of surface free energy method indicate the increase of adhesion energy (except in granite samples) and reduction of debonding energy in all modified samples. Generally, evaluations conducted by the use of both methods show that covering aggregates by micronized calcium carbonate has a positive effect on reducing moisture sensitivity of asphalt mixes.


Author(s):  
Ahmed Saidi ◽  
Ayman Ali ◽  
Wade Lein ◽  
Yusuf Mehta

The objective of this paper is to present a procedure for designing cold in-place recycling (CIR) mixtures through balancing rutting and cracking for these mixtures. Four CIR mixtures were prepared using two recycling agents (foamed and emulsified asphalts), and compacted at two gyration levels (30 and 70 gyrations). The CIR mixtures were prepared at a constant water content of 3% and a constant cement content of 1% while curing of the compacted samples was conducted by placing them in an oven for three days at 140°F (dry curing). The CoreLok device was used for measuring air voids in compacted samples. The rutting susceptibility of these mixtures was then evaluated using the asphalt pavement analyzer (APA) and dynamic complex modulus (|E*|) while resistance to cracking was assessed using the indirect tensile strength (ITS) test and fracture energy as determined using the semi-circular bend (SCB-FE) test. A demonstration of how these tests were utilized to select a performance balanced optimum binder content for each of the four CIR mixes was also presented. The developed balanced mix design approach was used successfully for designing four CIR mixtures and selecting the optimum binder content for each mix. The results also showed that using a higher compaction level leads to increasing both foamed and emulsified asphalt CIR mixtures’ ability to resist rutting. In terms of cracking, SCB-FE results showed that foamed asphalt mixtures were better at resisting cracking than emulsified asphalt CIR mixtures.


DYNA ◽  
2015 ◽  
Vol 82 (194) ◽  
pp. 52-56
Author(s):  
MARIA JOSE MARTINEZ-ECHEVARRIA ROMERO ◽  
Gema García-Travé ◽  
Mª Carmen Rubio-Gámez ◽  
Fernando Moreno-Navarro ◽  
Domingo Pérez-Mira

The reutilization of waste generated by industrial processes has become a majorenvironmental objective in scientific and technical research. In the construction sector, there is a broad range of techniques for the exploitation of different types of waste, which can then be used as a replacement for raw materials. This paper presents the results of a study of vinasse, a by-product of biomass ethanol, andanalyzes its viability as a bitumen modifier in asphalt mixes. For this purpose, four AC-16S asphalt mixes were evaluated for moisture sensitivity, plastic deformation, stiffness, and fatigue. The mix formulas were the following: (Mix 1) 50/70 bitumen; (Mix 2) 50/70 bitumen modified with 10% vinasse; (Mix 3) rubber bitumen; (Mix 4) rubber bitumen modified with 10% vinasse. The results of this study showed that bitumen modified with vinasse improved the mechanical performance of the AC-16S mix and also contributed to the valorization of vinasse waste.


2022 ◽  
Vol 961 (1) ◽  
pp. 012029
Author(s):  
Hasan H Joni ◽  
Ali H Abed

Abstract One of the most significant factors for a good transportation system is the quality of the road pavement. As a result, many steps have been made to address the concerns of moisture damage to roadways, including increasing pavement quality and structural design approaches. In the last few years, there has been an increase in the attention of respective engineers to enhance the asphalt performance and provides various types of modifiers and substituting the virgin of asphaltic materials with recyclable products, to attain sustainable while reducing the price of modified pavement mixture. This article discusses the performance of modified asphalt mixes and the most commonly used recycled product, crumbs rubber, which is used as a modifier in asphaltic mixes at various contents (0, 2.5, 5, 7.5, 10, and 15% by asphalt weight), and investigates the impact of the addition rubber particles on a critical characteristic of asphalt mixtures, particularly regarding their resistance to damage of moisture. The results showed that modification of asphalt binder with CR increased Marshall’s Stability, and the inclusion of 10% of CR recorded the highest increment, increasing by 30.25%. According to increased TSR and IRS, the addition of CR improved the asphalt mixture’s moisture resistance. The addition of 7.5 % of CR resulted in the largest values of TSR and IRS, increasing by 8.8% and 12.9% respectively. Additionally, this study aims at understanding the benefits and drawbacks of recycling rubber tires and to build a concept for effectively incorporating waste materials into road pavement.


2021 ◽  
Author(s):  
Iva Brkić ◽  
Aleksandra Deluka-Tibljaš ◽  
Marijana Cuculić ◽  
Ivana Pranjić

Porous asphalt is a bituminous material prepared in such a manner that it has a very high content of interconnected voids that allow passage of water and air in order to provide the compacted mixture with better drainage and noise reducing characteristic. The analysis of available regulations and scientific literature shows that the national standards of porous asphalt mixtures differ in type of granulometric envelopes, the type of bitumen and its content in the mixture and the limits of the air voids content in the mixture. In this paper, standards used for porous asphalt in Croatia are compared with the US, Australian and Dutch standards for this type of asphalt. In addition, samples prepared based on HRN EN 13108-7 and HRN EN 12697-17 requirements were tested and results were compared using Croatian and other available standards. This paper also investigates the effects of ambient temperature on abrasion loss of porous asphalt. The abrasion loss results are compared to the other standards.


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