The effect of hydrated lime addition in improving the moisture resistance of hot mix asphalt (HMA) (original) (raw)
Related papers
2012
Aggregate stripping is a failure which mostly occurs in asphalt pavements in conditions with high degree of moisture accompanied by hydrophilic aggregates. The use of lime is a recognized way to mitigate this problem and in this research, we aimed to investigate the lime effect by performing laboratory tests on various aggregates and different percent of Hydrated Lime additive to figure out the changes in some principal HMA design factors. Test results have been use in one of the major road construction projects in Iran, with aggregates susceptible to premature stripping. ASTM D3625 is used as a primary evaluation of aggregate tendency to striping and AASHTO T283 for examining the indirect tensile strength of asphalt mixtures. Evaluation of asphalt mixture durability against moisture is done by TSR ratio, MRR and fatigue index. Results in our tests in a real project show the capabilities of Hydrated Lime additives against the stripping phenomena.
Effect of Hydrated Lime on Asphalt Cement and Asphalt Mixtures Properties
2019
In 2014, it was noticed that, asphalt cement obtained from some Egyptian refineries did not meet the specification limits of asphalt cement 60/70 used in Egypt. Using this defective asphalt will produce low stability and high flow asphalt mixtures which leads to the formation of rutting and cracks in the pavement. This study has two objectives. The first objective is to investigate the effect of using hydrated lime on defective asphalt and also on its asphalt mixtures properties. While the second objective is to evaluate the performance of asphalt mix containing hydrated lime. To achieve these study objectives, an experimental program was designed. Selecting and performing qualification tests on aggregates and two specimens of asphalt. Asphalt specimens were defective asphalt and non-defective asphalt. Adding different percentages of hydrated lime to defective asphalt cement and performing some tests to determine the properties of modified asphalt. Then performing Marshall, loss of ...
Investigation of Hydrated Lime Effect in Asphalt Pavements
2015
Hydrated lime (HL) has been added to hot mix asphalt pavements over the years to improve the asphalt concrete mixtures in many ways. Although it has been repeatedly shown that the use of hydrated lime in asphalt concrete mixtures is beneficial, confusion still exists about the appropriate methods of adding hydrated lime to the mixtures to achieve the optimum modification of hydrated lime. The reasons why hydrated lime is so effective in asphalt mixtures lie in the strong interactions between the major components such as aggregate and bitumen. In this study, effects of hydrated lime in the asphalt pavements are investigated by performing Marshall Stability test, indirect tensile strength test, moisture susceptibility test and resilient modulus test. It can be concluded that, the addition of hydrated lime generally improved the fatigue properties of the asphalt mixture regardless the method of application to the mixtures. Asphalt mixtures modified with hydrated lime using wet method s...
Using Hydrated Lime in Hot Mix Asphalt Mixtures in Road Construction
Abstract: An increase in predicted pavement fatigue life for lower air void contents and higher asphalt content has been suggested by various investigations on asphalt concrete pavement mixtures. The strength and load carrying capacity of hot mix asphalt results from the aggregate framework created through particle-particle contact and interlock. Fines or mineral filler have a role since their presence directly influences the composition and performance of asphalt mixtures. The coarse aggregate framework is filled by the sand-sized material and finally by the mineral filler. At some point, the smallest particles lose contact becoming suspended in the binder not having the particle-particle contact that is created by the larger particles. In most road project asphalt mixtures, stone dust, cement and lime are used as fillers. The overall effect of mineral filler in hot mix asphalt specimens has been investigated through a series of laboratory tests. It seems that a behavior influenced by the adherence of fines to asphalt film has been developed. The optimum bitumen content requirement in case of stone filler is almost the same as for lime. The Marshall-flow increased with the use of lime filler, suggesting that the resistance of bituminous mixes to permanent deformation is improved.
Evaluations of Nano-Sized Hydrated Lime on the Moisture Susceptibility of Hot Mix Asphalt Mixtures
2012
The objective of this study was to evaluate the effect of nano-sized hydrated lime on the moisture susceptibility of the hot mix asphalt (HMA) mixtures in terms of three methodologies to introduce into the mixtures. The experimental design for this study included the utilizations of one binder source (PG 64-22), three aggregate sources and three different methods introducing the lime. A total of 12 types of HMA mixtures and 72 specimens were fabricated and tested in this study. The performed properties include indirect tensile strength (ITS), tensile strength ratio (TSR), flow, and toughness. The results indicated that the nano-sized lime exhibits better moisture resistance. Introducing process of the nano-sized lime will produce difference in moisture susceptibility.
THE EFFECT OF AGGREGATES QUALITY ON MOISTURE SUSCEPTIBILITY OF HOT MIX ASPHALT
IAEME PUBLICATION, 2020
Aggregates make up the most of total volume of hot mix asphalt, and hence, it is necessary to ensure that the aggregates used were suitable for the asphaltic mixture. The objective of this study is to evaluate the effect of using different aggregates on asphaltic mixture with additional of two different anti-stripping agents, namely 2% hydrated lime and 0.5% Wetbond-SP, to assess the moisture susceptibility of the asphaltic mixture. There were three laboratory tests conducted, which are Marshall, Cantabro Loss, and Indirect Tensile Strength tests and there were three natural aggregates used in this study. From the research results, it was found that adding hydrated lime and Wetbond-SP could improve the stability of the specimens constructed with Aggregate B and Aggregate, but not with Aggregate A. Based on the Cantabro Loss and the ITS tests, it could be concluded that Wetbond-SP was more effective to improve the moisture susceptibility of the asphaltic mixture regardless of which aggregate was used, than the hydrated lime
Increasing the Durability of Asphalt Mixtures by Hydrated Lime Addition: What Mechanisms?
2012
Hydrated lime has been known as an additive for asphalt mixtures from their very beginning. It experienced a strong interest during the 1970s in the USA, when moisture damage and frost became some of the most pressing pavement failure modes of the time. Given its extensive use in the past 40 years, hydrated lime has been seen to be more than a moisture damage additive: It reduces chemical ageing of the bitumen and stiffens the mastic more than normal mineral filler above room temperature. All these properties impact durability and hydrated lime is now seen has an additive to increase asphalt mixture durability. This article is a literature review on the fundamentals of hydrated lime effect. The reasons why it is so effective lie in the strong interactions between aggregate and bitumen, and a combination of 4 effects, two on the aggregate and two on the bitumen. Hydrated lime modifies the surface properties of aggregate, allowing for the development of a surface composition and rough...
Moisture susceptibility assessment of hydrated lime modified asphalt mixture and surface energy
International Journal of Pavement Engineering, 2020
The influence of hydrated lime on moisture susceptibility of asphalt mixture was assessed using a combination of surface energy measurements and modified saturation ageing and tensile stiffness (SATS) test. Four aggregate types, which are commonly used for manufacturing asphalt mixtures in the UK have been selected with 40/60 penetration grade bitumen. These aggregates were from various rocks across the UK which includes felsic intrusive, calcite sedimentary, mafic extrusive and argillaceous sandstone rock sources. Two out of four aggregate sources including felsic intrusive, and argillaceous sandstone showed improvement with the hydrated lime replacement considering results from both surface free energy measurements and modified SATS test, but the performance of aggregates from calcite sedimentary, mafic extrusive rocks remained unaffected. Mineralogical testing of the aggregates, using MLA, showed considerable differences between four aggregate types used in this study. Minerals such as albite, epidote, quartz and chlorite were found predominate in aggregates from felsic intrusive, and argillaceous sandstone sources. Aggregates from calcite sedimentary rock were found abundant in calcite mineral while Argillaceous sandstone aggregates were found rich in chlorite and albite. The difference in the behaviour of four aggregate types to the HL replacement can be credited in part to mineralogical composition of different aggregates. The hydrated lime content of 1% was observed better than 2% in the aggregates who showed improved performance with the use of HL. The trends obtained in the surface energy measurements have been found similar to SATS technique. The results clearly illustrate a close agreement between both techniques used in this study for the evaluation of moisture susceptibility. A comparison between ITSM and ITS test after SATS conditioning was also undertaken as some researchers believe that ITS being destructive in nature gives more distinctive results. But the results of ITSM and ITS very found very similar to each other after SATS conditioning in terms of retained strength or retained stiffness.
The Effect of Hydrated Lime Mixing Forms and Ratios on Performance in Asphalt Pavements
Teknik Dergi
In this study; the water damage problem and indirect tensile strengths (ITS) were investigated for different hydrated lime (HL) additive ratios and adding methods. In this regard, identical briquettes modified with hydrated lime have been produced. HL was used both in the bituminous binder (wet method) and as part of the filler aggregate. The hydrated lime was added in two different ways to form the defined equivalent ratios. By producing nine identical briquettes in each option, the values of water damage and ITS in both unconditioned and modified mixtures were compared, and the level of significance differences between the identical briquettes and mixtures was questioned. Increasing the HL content increases the standard deviation between identical samples in terms of ITS. The workability of the mixture is adversely affected by the increase in the hydrated lime ratio. When HL is mixed into the asphalt cement (AC), the standard deviations of ITS values among identical samples remain lower due to the increase in mixing rates. Increasing the ratio of adding HL to the asphalt cement reduces the ITS ratios compared to the option of adding filler to aggregate. If HL is added to the mixture in low HL content, the water damage ratios show, on average, higher water damage resistance (15% higher) than the HL being added to the AC. However, if the HL content is increased to medium and high levels, mixing HL to AC creates higher water damage resistance than adding it as filler.