› › The Effect Of Moisture On Laboratory Prepared Asphalt Mixtures

The Effect of Moisture on Laboratory-Prepared Asphalt Mixtures

Author : W. Akili

Publisher :

Page : 11 pages

File Size : 34,75 MB

Release : 1993

Category : Aggregate proportions

ISBN :

Get eBook

Book Description

This paper presents the results of a laboratory study conducted to examine the water-induced damage of compacted and loose asphalt-aggregate mixtures from Riyadh, Saudi Arabia.One asphalt cement and two typical aggregate sources (A and B) were used to prepare asphalt mixtures.Test methods used included the Marshall stability ratio, the wet-dry indirect tensile test (Lottman) and coating and stripping tests of uncompacted mixtures (ASTM D 1664, Test Method for Coating and Stripping of Bitumen-Aggregate Mixtures, and ASTM D 3625.Test Method for Effect of Water on Bituminous-Coated Aggregate-Quick Field Test).





Effect of Testing Conditions on Laboratory Moisture Test for Asphalt Mixtures

Author : Junyan Yi

Publisher :

Page : 12 pages

File Size : 43,98 MB

Release : 2016

Category : Aging

ISBN :

Get eBook

Book Description

Moisture damage is one of the major causes of premature failure in asphalt pavements, and it also accelerates the severity of other distresses. To date, no moisture test has been widely accepted that is reliable and practical in predicting the field moisture performance of the asphalt mix during the design stage. One reason is because the sample conditioning methods cannot represent the field conditions, resulting in inconsistent results with the field performance of some mixtures. Taken into account this concern, this paper investigates how different testing conditions, including sample preparation, moisture saturation, and loading methods, can affect the results of laboratory moisture tests. In conclusion, it is found that the degree of vacuum pressure for achieving moisture saturation and air voids distribution has a significant impact on the moisture testing results. Multiple freeze-thaw cycles have a limited effect on the variation of mechanical performance (i.e., compressive dynamic modulus). If one or several freeze-thaw cycles are to be used in a moisture test, the effect of aging should be considered. It is recommended that a sample without coring and cutting should be used for a moisture test as the coring and cutting process is found to change the air voids distribution, i.e., the percent of connected air voids, thus making the sample not representative to the field condition. Finally, the moisture test results are more sensitive under tension mode than under compression mode.



The Effect of Moisture on the Performance of Asphalt Mixtures

Author : CA. Bell

Publisher :

Page : 22 pages

File Size : 43,68 MB

Release : 1985

Category : Compacting

ISBN :

Get eBook

Book Description

This paper presents the results of a laboratory study to investigate the effects of mixing moisture on mechanical properties of asphalt mixtures. The potential benefits of lime and Pavebond Special were also evaluated. The repeated load diametral test device was used to measure the mixture performance in terms of the resilient modulus, fatigue, and permanent deformation characteristics of laboratory specimens prepared with and without moisture (0, 1, and 3%) and with and without lime (1%) and Pavebond (0.5%). Mixtures were prepared that were representative of two projects for which considerable field data were available. One project utilized low quality and high absorptive aggregate and the other good quality aggregate. To evaluate the long-term durability of mixtures, they were tested before and after conditioning using the Lottman approach.



Laboratory Evaluation of Anti-strip Additives in Hot Mix Asphalt

Author : Bradley J. Putnam

Publisher :

Page : 178 pages

File Size : 22,39 MB

Release : 2006

Category : Asphalt

ISBN :

Get eBook

Book Description

The use of hydrated lime or other liquid anti stripping agents (ASA) is the most common method to improve the moisture susceptibility of asphalt mixes. However, most laboratory test conditions used to evaluate the moisture susceptibility of the mixes are only for a short duration of time. This might not be a good representation of the field conditions (i.e., several months or years of service). Thus, a study to evaluate the effects of conditioning the mixes for longer durations was initiated. Also, another problem with the use of the liquid anti stripping agents is their heat storage stability. This report addresses these two issues, by preparing and testing mixtures made with fresh binder for indirect tensile strength after conditioning the samples for 1, 7, 28, 90 and 180 days, and samples prepared from binder stored for three days at 160° C after conditioning them for 1, 28 and 90 days. The results of this study indicated that hydrated lime and the liquid anti stripping agents were equally effective for the mixes used in this research when conditioned beyond one day. In the case of samples prepared from stored binder, there was no significant difference in the effectiveness of hydrated lime and the liquid anti stripping agents even after conditioning for one day. Though it was observed that none of the ASA treatments performed better than others in the case of samples prepared with stored binder, it was also observed that almost all mixes gave significantly similar wet ITS and TSR values as samples prepared from fresh binder.



Investigation of Moisture Susceptibility of Warm Mix Asphalt (WMA) Mixes Through Laboratory Mechanical Testing

Author : Wenyi Gong

Publisher :

Page : 148 pages

File Size : 32,94 MB

Release : 2011

Category :

ISBN :

Get eBook

Book Description

Abstract: The presence of moisture can lead to serious damage in Hot Mix Asphalt mixes and failures of HMA pavements. This is of an even greater concern for Warm Mix Asphalt (WMA) due to the use of much lower production temperatures which may not be high enough to completely dry the aggregates. In this Maine DOT study, the use of fracture energy parameters was evaluated to determine the influence of incomplete drying of mixes on their mechanical properties. Fracture energy based parameters (ER: energy ratio; RER: ratio of energy ratio) were determined from the following indirect tensile testing on mixes with fully and partially dried aggregates, some of which were subjected to moisture conditioning: Resilient modulus (Mr), creep compliance, and indirect tensile strength (ITS) strength at 5°C. The results indicate that: i. resilient modulus, creep compliance, and indirect tensile strength were all affected by the presence of moisture in mixes; ii. the trend and degree of influence by moisture for the different mechanical parameters are different; iii. The moisture conditioning process has caused larger decreases in resilient modulus and ITS values than incomplete drying of aggregates; however, the same moisture conditioning process has caused much larger decreases in modulus and ITS in asphalt mixes prepared with incompletely dried aggregates than the counterparts prepared with fully dried aggregates; and iv. fracture energy-based parameters (ER and RER) appear to be more distinctive moisture effect/damage indicators than the other parameters.





A Laboratory Study of the Effectiveness of Various Additives on Moisture Susceptibility of Asphalt Mixtures

Author : P. Hao

Publisher :

Page : 8 pages

File Size : 44,10 MB

Release : 2006

Category : Asphalt

ISBN :

Get eBook

Book Description

Antistripping additives are used routinely to improve water resistance of asphalt mixtures. Different additives have different improvement effectiveness in water resistance. In this study, the effects of various additives on the moisture susceptibility of asphalt mixture are studied with the retained Marshall stability test, Lottman test, and immersion wheel tracking test. Asphalt mixtures were modified with Portland cement, hydrated lime, lime slurry, and liquid antistripping agents. The results show that the lime-slurry-treated asphalt mixtures have better resistance to moisture susceptibility than mixtures treated with other materials, and have better long-term moisture stability than the liquid antistripping agents. The liquid-antistripping-agent-treated asphalt mixtures have better resistance to moisture stability before long-term aging. Portland-cement-treated asphalt mixtures show slightly improved water resistance. Asphalt mixtures become more resistant to moisture damage through short-term aging. It was confirmed that the Lottman and the immersion tracking methods are better methods to evaluate moisture susceptibility than the retained Marshall stability methods.





Rheometry of Pastes, Suspensions, and Granular Materials

Author : Philippe Coussot

Publisher : John Wiley & Sons

Page : 311 pages

File Size : 48,31 MB

Release : 2005-06-14

Category : Technology & Engineering

ISBN : 0471720569

Get eBook

Book Description

A comprehensive examination of rheometry theory and its practical applications This publication enables readers to understand and characterize the flow properties of complex fluids and, with this knowledge, develop a wide range of industrial and consumer products. The author fills a gap in the current literature by presenting a comprehensive description of the rheological behavior of pastes, suspensions, and granular materials and by offering readers the rheometrical techniques needed to effectively characterize these materials. With his extensive experience in both academic and industrial research, the author is able to take the field to a new level in: * General schematic classification of the behavior of pastes,suspensions, and granular materials * Systematic review, analysis, and quantification of experimental problems with complex fluids * Insight into the flow behavior of complex fluids gained through the most recent discoveries and research techniques * Comprehensive rheometrical analysis of data obtained from research across a broad range of industries In addition to gaining a thorough understanding of the theory underlining rheometry, readers discover its many practical applications. Throughout the publication, specific examples are provided that illustrate how theory is applied, including examples involving food, civil engineering, cosmetics, pharmaceuticals, paper coatings, paint and ink, ceramics, sewage sludges, granular materials, and natural materials. In summary, this publication provides a comprehensive review of the behavior of pastes, suspensions, and granular materials as well as detailed analysis of rheometrical techniques. Everything needed to determine the behavior and movement of complex fluids is provided. It is, therefore, a recommended resource for rheologists, engineers, and researchers, as well as students who deal with complex fluids in product formulation, quality and process control, and process plant design.