Laboratory evaluation of the effect of bentonite on performance of bitumen and hot mix asphalt mixtures

2016 ◽  
Vol 34 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Alireza Ameli ◽  
Rezvan Babagoli ◽  
Seyed Erfan Tabatabaei Razi
Author(s):  
M. Shane Buchanan ◽  
L. Allen Cooley

Tender hot-mix asphalt mixtures have been observed and experienced by paving contractors for many years. However, during the field compaction of coarse-graded Superpave® mixes, a "tender zone," not a true tender mix, is sometimes experienced. The tender zone is a range of mix compaction temperatures during which the mixture exhibits instability during roller action. Many possible causes of the tender zone have been presented, including differences in laboratory and production absorption, mix moisture, a low dust-to-asphalt ratio, increased asphalt binder film thickness, and a temperature differential with the lift. A study was conducted to document and evaluate field mixtures exhibiting the tender zone to determine the possible cause(s) of its occurrence. Documentation included mix-, production-, and construction-related items. Laboratory evaluation consisted of mixture gradation and volumetric testing along with Superpave asphalt binder testing with the project asphalt binder before and after steam distillation. Project results failed to clearly identify one particular reason for the occurrence of the tender zone. However, it is believed that the tender zone was a result of field absorption being less than the design absorption and increased asphalt binder film thickness acting in conjunction with an inherent temperature differential within the lift.


2012 ◽  
Vol 174-177 ◽  
pp. 82-90 ◽  
Author(s):  
Ju Nan Shen ◽  
Zhao Xing Xie ◽  
Fei Peng Xiao ◽  
Wen Zhong Fan

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.


2013 ◽  
Vol 65 (2) ◽  
Author(s):  
Mohd Rosli Hainin ◽  
Gatot Rusbintardjo ◽  
Mohd Azizi Abdul Aziz ◽  
Asmah Hamim ◽  
Nur Izzi Md. Yusoff

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.


2011 ◽  
Vol 2207 (1) ◽  
pp. 107-116 ◽  
Author(s):  
Nathan Morian ◽  
Elie Y. Hajj ◽  
Charles J. Glover ◽  
Peter E. Sebaaly

2018 ◽  
Vol 10 (8) ◽  
pp. 2590 ◽  
Author(s):  
Debora Acosta Alvarez ◽  
Anadelys Alonso Aenlle ◽  
Antonio Tenza-Abril

Recycled Aggregates (RA) from construction and demolition waste (CDW) are a technically viable alternative to manufacture of asphalt concrete (AC). The main objective of this work is to evaluate the properties of hot asphalt mixtures that have been manufactured with different sources of CDW (material from concrete test specimens, material from the demolition of sidewalks and waste from prefabrication plants) from Cuba. Dense asphalt mixtures were manufactured with a maximum aggregate size of 19 mm, partially replacing (40%) the natural aggregate fraction measured between 5 mm and 10 mm with three types of RA from Cuba. Marshall specimens were manufactured to determine the main properties of the AC in terms of density, voids, stability and deformation. Additionally, the stiffness modulus of the AC was evaluated at 7 °C, 25 °C and 50 °C. The results corroborate the potential for using these sources of CDW from Cuba as a RA in asphalt concrete, thereby contributing an important environmental and economic benefit.


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