Investigation of Aging in Hydrated Lime and Portland Cement Modified Asphalt Concrete at Multiple Length Scales

Mineral filler is the finest fraction of aggregate (smaller than 75 gm) used in the production of asphalt paving mixed. It is essential for producing a mixture that is dense, cohesive, durable, and resistant to water penetration. In spite of the fact that filler is very small proportion of the total aggregates in the mix, due to its rather high affinity for asphalt, the changes in the type of the filler can cause the paving mixture to perform satisfactorily during the design life or deteriorate rapidly under the effect of traffic and environmental impact. The objective of this study is to investigate the effect of mineral filler types (three types, limestone dust, Portland cement and hydrated lime) in the durability of asphalt concrete mixture. To achieve the objective of this study, Marshall mix design method was utilized to produce asphalt concrete mixes at their optimum asphalt content. The mixes were, then, tested to investigate their durability properties including moisture damage and fatigue characteristics. The results indicated that the mixes prepared with hydrated lime have superior resistance to moisture damage in comparison with Portland cement and lime stone dust. On the other hand, the mixes prepared with Portland cement type of filler showed better resistance to the fatigue failure of asphalt concrete pavement.

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Testing and Modeling of Fine Aggregate Matrix and Its Relationship to Asphalt Concrete Mix

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/2507-13 ◽

2015 ◽

Vol 2507 (1) ◽

pp. 120-127 ◽

Cited By ~ 15

Author(s):

Padmini Gudipudi ◽

B. Shane Underwood

Keyword(s):

Asphalt Concrete ◽

Mechanical Response ◽

Strong Relationship ◽

Axial Direction ◽

Unique Element ◽

Fine Aggregate ◽

Length Scales ◽

Multiple Length Scales ◽

Fine Aggregate Matrix ◽

Term Performance

The study of the fundamental properties of asphalt concrete (AC) can be used to improve and maximize the performance potential of these materials. In this paper, the fundamental approach is examined by coupling its essential hypothesis to an investigation of AC across multiple length scales. Asphalt and aggregate materials from the state of Arizona were used to prepare fine aggregate matrix (FAM) and AC samples. Laboratory tests on these materials were conducted to investigate the modulus and damage characteristics for two binder types. A comparison of mechanical response across length scales is not new, and the unique element of this study is testing both materials in the axial direction (tension–compression) for both modulus and fatigue. A strong relationship between these two materials was observed; this relationship suggests that tests on FAM samples can provide much needed insight in understanding the behavior of AC for various conditions. The study also investigated upscaling of the FAM properties to those of the AC mixture through a homogenized continua approach. Multiple upscale models were evaluated in this upscaling process, but the chosen method produced the best overall match to experimental data. The findings from this modeling effort were also used to upscale the behaviors of FAM to identify the fatigue characteristics of AC mixtures and evaluate the long-term performance of the material.

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Assessing the Moisture and Aging Susceptibility of Cold Mix Asphalt Concrete

Journal of Engineering ◽

10.31026/j.eng.2021.02.05 ◽

2021 ◽

Vol 27 (2) ◽

pp. 59-72

Author(s):

Zahraa Ahmed Samor ◽

Saad Issa Sarsam

Keyword(s):

Tensile Strength ◽

Portland Cement ◽

Asphalt Concrete ◽

Ordinary Portland Cement ◽

Asphalt Binder ◽

Asphalt Mixture ◽

Hydrated Lime ◽

Technical Requirements ◽

Concrete Mixtures ◽

Age Related

Laboratory experience in Iraq with cold asphalt concrete mixtures is very limited. The design and use of cold mixed asphalt concrete had no technical requirements. In this study, two asphalt concrete mixtures used for the base course were prepared in the laboratory using conventional cold-mixing techniques to test cold asphalt mixture (CAM) against aging and moisture susceptibility. Cold asphalt mixtures specimens have been prepared in the lab with cutback and emulsion binders, different fillers, and curing times. Based on the Marshal test result, the cutback proportion was selected with the filler, also based on the Marshal test emulsion. The first mixture was medium setting cationic emulsion (MSCE) as a binder, hydrated lime, and ordinary portland cement as a filler (7.95% MSCE + 2%HL + 3% OPC). The second mixture used was medium curing cutback (MC-250) as a binder and ordinary portland cement as a filler (5.18% MC 250 + 5% OPC). The indirect tensile strength (ITS) of the samples was measured at 25 ° C. It was found that the cold mix with the MSCE binder had a high ITS value relative to the cold mix with the cutback asphalt binder (MC-250). The dry mixture of MSCE ITS was approximately 3.77 times the dry mixture of MC-250. The MSCE wet mix was about 4.2 times the wet MC-250 mix. Tensile strength ratio result (TSR %) for the MSCE binder mix and the cutback MC-250 binder mix showed that the MSCE mix has a reasonable moisture resistance (77% ) compared to the MC-250 mix (69.2 %). The aging test and aging ratio result showed that asphalt binder oxidation has a significant effect on age-related pavement degradation as it changes the time-temperature relationship depending on the viscoelastic properties of the asphalt binder. The result clearly showed that the MSCE binder mix had a high resistance to aging (440 Kpa) compared to the cutback (MC-250) binder mix (110 Kpa). In contrast, the MSCE aging ratio (90 %) was higher than the MC-250 ratio (85 %).

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Performance Evaluation of Plant Produced Warm Mix Asphalt

Journal of Engineering ◽

10.31026/j.eng.2018.05.10 ◽

2018 ◽

Vol 24 (5) ◽

pp. 145 ◽

Cited By ~ 2

Author(s):

Amjad H. Albayati

Keyword(s):

Portland Cement ◽

Asphalt Concrete ◽

New Technology ◽

Permanent Deformation ◽

Performance Testing ◽

Hydrated Lime ◽

Warm Mix Asphalt ◽

Load Test ◽

Concrete Mixtures ◽

Limestone Dust

Warm mix asphalt (WMA) is relatively a new technology which enables the production and compaction of asphalt concrete mixtures at temperatures 15-40 °C lower than that of traditional hot mix asphalt HMA. In the present work, six asphalt concrete mixtures were produced in the mix plant (1 ton each) in six different batches. Half of these mixes were WMA and the other half were HMA. Three types of fillers (limestone dust, Portland cement and hydrated lime) were used for each type of mix. Samples were then taken from these patches and transferred to lab for performance testing which includes: Marshall characteristics, moisture susceptibility (indirect tension test), resilient modulus, permanent deformation (axial repeated load test) and fatigue characteristics (third point flexural beam test). The obtained results indicated that the performance of WMA is enhanced when using the hydrated lime as filler in comparison with the limestone dust and Portland cement fillers. Better fatigue life was obtained for WMA using hydrated lime filler in comparison with HMA. Regardless the filler type, the Marshall properties of WMA satisfy the requirement of local specification, other properties of WMA were relatively lower than the HMA.

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Evaluation of Cold Mix Asphalt Concrete Properties

10.47890/jceid/2020/sisarsam/12045784 ◽

2020 ◽

Vol 1 (1) ◽

Author(s):

Saad Issa Sarsam ◽

Zahraa Ahmed Samor

Keyword(s):

Fly Ash ◽

Portland Cement ◽

Asphalt Concrete ◽

Coal Fly Ash ◽

Hydrated Lime ◽

Concrete Properties ◽

Base Course ◽

Limestone Dust

Cold mix asphalt concrete is considered as a sustainable and green pavement, the aggregates and the binder can be mixed, laid, and compacted without consumption of energy. In this investigation, an attempt has been made to prepare cold mix asphalt concrete for base course construction. Two types of liquid binder, named Cationic emulsion Medium Setting CMS and Medium Curing cutback MC-250 have been implemented in preparation of Marshall specimens. Four types of additives, named Portland cement, coal fly ash, limestone dust and hydrated lime have been tried. Mixtures were subjected to aeration, then compacted. However, Specimens were subjected to curing before testing. It was concluded that mixtures with (optimum cutback content + 5% cement and 4 hours aeration and 24 hours curing at 60°C) and (optimum emulsion content +2% hydrated lime +3% cement or fly ash and 4 hours aeration at 25°C and 24 hours curing at 60°C) satisfies the volumetric and Marshall properties requirements for base course. It was recommended that increasing the aeration and curing periods is beneficial for the cold mix asphalt concrete in satisfying the specification requirements for base course. Keywords:Cold Mix; Asphalt Concrete; Cement; Lime; Fly ash; Marshall; Aeration; Curing;

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