scholarly journals A Laboratory Investigation into the Effects of Coarse Aggregate Angularity on Performance of WMA

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Jie Ji ◽  
Peng Zhai ◽  
Wenhua Zheng ◽  
Zhi Suo ◽  
Ying Xu
Keyword(s):  
Los Angeles ◽  
Coarse Aggregate ◽  
Asphalt Binder ◽  
Design Procedure ◽  
Thermal Cracking ◽  
Moisture Susceptibility ◽  
Los Angeles Abrasion ◽  
Modified Asphalt Binder ◽  
Air Void ◽  
Sharp Corners

This study evaluated the effects of coarse aggregate angularity (CAA) on the performances of warm mix asphalt (WMA) because previous studies have predominantly focused on the effects of CAA on the hot mix asphalt (HMA) performances. Five different CAAs were fabricated using Los Angeles abrasion test, and the digital image processing method was used to identify the CAA. Five mixes with different combinations of CAA and Sasobit-modified asphalt binder were prepared according to the Marshall mix design procedure. The performances such as the resistance to rutting and thermal cracking, moisture susceptibility, and volumetric characteristics of WMA were evaluated. The test results indicated that the CAA value was linearly declined with the abrasive wearing passes increased. Higher CAA value improved the potential to resistance to rutting of WMA but was not suitable to enhance the resistance to thermal cracking of WMA due to sharp corners that caused higher stress concentration. In addition, WMA was more prone to develop numerous macrocracking, which resulted in lower moisture susceptibility due to higher CAA value inducing higher air void, VMA, and VCA of WMA.

scholarly journals Assessing the moisture susceptibility of aggregates with Los Angeles abrasion test

2017 ◽  
Author(s):  
Adelia Dwidarma Nataadmadja ◽  
Oki Setyandito ◽  
Eduardi Prahara ◽  
Ida Riyanti
Keyword(s):  
Los Angeles ◽  
Moisture Susceptibility ◽  
Abrasion Test ◽  
Los Angeles Abrasion

scholarly journals The effect of coarse aggregate hardness on the fracture toughness and compressive strength of concrete

2019 ◽  
Vol 258 ◽  
pp. 04011
Author(s):  
Atur P. N. Siregar ◽  
Emma L. Pasaribu ◽  
I Wayan Suarnita
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
Los Angeles ◽  
Coarse Aggregate ◽  
Concrete Aggregate ◽  
Beam Size ◽  
Intensity Factors ◽  
Coarse Aggregates ◽  
Los Angeles Abrasion ◽  
Compressive Strength Of Concrete

Coarse aggregate is the dominant constituent in concrete. Aggregate hardness is a variable needed to investigate in determining its effect on the critical stress intensity factors (KIC), dissipated fracture energy (Gf) and compressive strength (fc’) of the concrete. The hardness of coarse aggregate based on Los Angeles abrasion values of 16.7%., 22.6%, and 23.1% was used incorporated with Portland Composite Cement (PCC), and superplasticizer to create specimens. Cubes of 150x150x150 mm were employed to determine the fc’, and four beam sizes: 50x100x350 mm, 50x150x500 mm, 50x300x950 mm and 50x450x1250 mm were engaged to determine KIC and Gf. The fc’ and Gf of specimens manufactured by three different hardness of coarse aggregates were 45, 43, 40 MPa and 89.4, 54.0, 56.3 N/m respectively. KIC of specimens was 138.9, 119.4 and 114.1 MPa.mm1/2 for beam size of 50x100x350 mm; 148.2, 115.8 and 108.8 MPa.mm1/2 for beam size of 50x150x500 mm; 230.9, 183.1 and 157.9 MPa.mm1/2 for beam size of 50x300x950 mm; and 293.2, 248.1 and 244.3 MPa.mm1/2 for beam size of 50x450x1250 mm. Experimental results showed that decreasing hardness of coarse aggregate was found to have significant effect on the fracture toughness rather than on the compressive strength of concrete.

Use of Screenings to Produce Hot-Mix Asphalt Mixtures

2003 ◽  
Vol 1832 (1) ◽  
pp. 59-66 ◽  
Author(s):  
L. Allen Cooley ◽  
Jingna Zhang ◽  
Michael H. Huner ◽  
E. Ray Brown
Keyword(s):  
Hot Mix Asphalt ◽  
Asphalt Binder ◽  
Cellulose Fiber ◽  
Fine Aggregate ◽  
Structural Improvement ◽  
Maintenance And Rehabilitation ◽  
Modified Asphalt Binder ◽  
Maximum Particle ◽  
Air Void ◽  
Different Sources

Thin-lift hot-mix asphalt (HMA) layers are utilized in almost every maintenance and rehabilitation application. These mix types require smaller maximum particle sizes than do most conventional HMA surface layers. Although the primary functions of thin-lift HMA are to level the pavement surface, smooth the surface, or slow the deterioration of the existing pavement, or all three, these mixes may also provide some structural improvement, depending on the layer thickness placed. The use of manufactured aggregate screenings (fine aggregate stockpiles) as the sole aggregate portion of an HMA mixture was evaluated in this study. Mixes of this nature have the potential for use as thin-lift HMA layers. Two different sources of aggregate screenings, granite and limestone, were utilized to design mixtures at varying design air void contents and then tested for rut susceptibility. The use of a neat versus a modified asphalt binder was also evaluated, as well as the potential advantages of cellulose fiber additives. These mixtures using 100% manufactured screenings proved to be acceptable with regard to rutting resistance. No work was performed in this study to examine thermal cracking or durability.

Experimental Study on Pavement Performance of SEBS Modified Asphalt Mixture

2010 ◽  
Vol 168-170 ◽  
pp. 906-911
Author(s):  
Chuan Feng Zheng ◽  
Lei Wang ◽  
Da Jun Zhao
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Pavement Performance ◽  
Moisture Susceptibility ◽  
Modified Asphalt ◽  
Modified Asphalt Binder ◽  
Beam Bending ◽  
And Performance ◽  
Wheel Tracking ◽  
Sbs Modified Asphalt

pavement performance of SEBS modified asphalt mixture are analyzed. Dynamic shear rhometer(DSR) experiments were performed to evaluate the rheology properties of SEBS modified asphalt binder and performance of SEBS modified asphalt mixture was evaluated based on laboratory experiments, experiments included: wheel tracking, moisture susceptibility, low-temperature beam bending and fatigue. The results shows that the rheology properties of SEBS modified asphalt binder are more ideal than SBS modified asphalt binder on anti-fatigue effect. Tensile stress ratio(TSR) of SEBS modified asphalt mixture increases 5.0%, tensile strength increases 6.1% and tensile strain increases 19.8%, though the dynamic stability(DS) decreases 3.1%, the fatigue life-span increases significantly compared with SBS modified asphalt mixture. It means that pavement performance of SEBS modified asphalt mixture is better than SBS modified asphalt mixture, and it is more applicable to be utilized in highway engineerings and some special engineerings such as bridge deck pavement that need anti-fatigue performance.

MECHANICAL PROPERTIES OF POROUS ASPHALT WITH NANOSILICA MODIFIED BINDER

2016 ◽  
Vol 78 (7-2) ◽  
Author(s):  
Khairil Azman Masri ◽  
Ahmad Kamil Arshad ◽  
Mohamad Saifullah Samsudin
Keyword(s):  
Mechanical Properties ◽  
Los Angeles ◽  
Resilient Modulus ◽  
Design Method ◽  
Asphalt Binder ◽  
Total Sample ◽  
Porous Asphalt ◽  
Abrasion Loss ◽  
Los Angeles Abrasion ◽  
Modified Binder

This paper evaluates the mechanical properties of porous asphalt (PA) with nanosilica (NS) modified binder in terms of its Abrasion Loss, Binder Draindown, Resilient Modulus and Moisture Susceptibility. These tests are essential to evaluate the performance of NS-PA towards the resistance of moisture induced damage, external loads, abrasion and interlocking structure of PA. Due to porous nature of PA, it is expose to moisture damage and binder draindown. Besides that, raveling is another major problem that closely related to PA. Thus, nanotechnology was promoted in this study in order to enhance the performance of PA. Six different percentages of nanosilica were mixed with PEN 60-70 type of binder in this study. Then, all these blended modified binder were used to prepare PA samples using Marshall Mix Design Method. Nanoparticle used in this study was Nanosilica with the average size of 10 to 15 nanometer. Binder Draindown Test was done using a metal basket with 3mm perforation. Then, abrasion loss value was evaluated using Los Angeles Abrasion Machine without steel ball. In accordance to Public Work Department of Malaysia Specification (JKR/SPJ/2008), it is stated that binder draindown for PA should not be more than 0.3% of total weight of sample, while abrasion loss should not be more than 15% also by weight of total sample. The results for Cantabro Loss Test and Binder Draindown Test indicated that 4% NS was the effective amount of NS to reduce the abrasion loss and binder drained of NS-PA. The maximum resilient modulus value for NS-PA was 4362 MPa while TSR value 91% (2% NS). Meanwhile, for conventional PA (0% NS), resilient modulus value was only 3036 MPa and TSR value 74%. From both tests were also concluded that the optimum amount of NS required for PA to archieved both value was 2%. It can be concluded that with proper concentration, the existence of NS is capable to enhance the physical and rheological properties of asphalt binder and at the same time it dispersed well in asphalt binder. Thus, the performance of PA with NS modified binder is also enhanced.

scholarly journals Effect of Nanoclays on Moisture Susceptibility of SBS-Modified Asphalt Binder

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Han Wang ◽  
Yinchuan Guo ◽  
Aiqin Shen ◽  
Xiaolong Yang ◽  
Peng Li
Keyword(s):  
Asphalt Binder ◽  
Moisture Susceptibility ◽  
Force Microscopy ◽  
Modified Asphalt ◽  
Atomic Force ◽  
Modified Binders ◽  
Modified Asphalt Binder ◽  
Water Damage ◽  
Styrene Butadiene ◽  
Sbs Modified Asphalt

Moisture susceptibility plays an important role in the damage of asphalt pavement. Failure occurs when asphalt is removed from the aggregate particles due to the decreased adhesion between the asphalt and aggregate in comparison with that between water and the aggregate. In recent years, efforts utilizing nanomaterials to improve the diverse properties of asphalt have proven to be effective. In this study, three types of nanoclays were used to modify styrene-butadiene-styrene- (SBS-) modified asphalt. The resistances to water damage of the modified binders were evaluated using the surface free energy (SFE) and atomic force microscopy (AFM). The results revealed that the total SFE decreased and the energy ratio (ER) increased when the asphalt binder was modified with the nanoclays, indicating that the addition of nanoclays can improve the moisture resistance of these aggregate-binder systems. After immersion, a decreased amount of bee structures was observed in both the SBS and nanoclay-modified asphalts due to the interactions between water and bitumen. However, the residual amount of bee structures was higher in the nanoclay-modified asphalts than in the SBS-modified asphalt, indicating that the addition of nanoclay makes the surface morphology of asphalt more resistant to water damage. Finally, freeze-thaw splitting tests were used to verify the results obtained through the SFE and AFM tests.

Utilization of Gneiss in Asphalt Concrete Mixtures

2009 ◽  
Vol 620-622 ◽  
pp. 1-4 ◽  
Author(s):  
Shao Peng Wu ◽  
De Ming Hu ◽  
Ling Pang ◽  
Hong Wang
Keyword(s):  
Los Angeles ◽  
Physical Properties ◽  
Hydrated Lime ◽  
Fine Aggregate ◽  
Moisture Susceptibility ◽  
Los Angeles Abrasion ◽  
Concrete Mixtures ◽  
Low Temperature Cracking ◽  
Flakiness Index ◽  
Marshall Stability

Construction of the pavement has consumed a huge amount of high grade aggregates, such as basalt, limestone etc. In some region, these aggregates are very scarce and have to be produced and transported from far aggregate quarries which would cause the waste of energy and resources as well as the increase of cost. Large quantities of gneiss exist in China, the use of gneiss as aggregates might help meet the highway constructing demands and save. In this paper, the feasibility is analyzed with respect to different aspects. Physical properties of gneiss aggregate were evaluated using Los Angeles abrasion, specific gravity and flakiness index. Mixture properties were characterized in terms of Marshall stability, moisture susceptibility, soak wheel track and low temperature cracking resistance property. Experiment results indicate that the physical properties of gneiss aggregates can satisfy the related specifications and these gneiss materials as aggregates can be used in asphalt pavement. Results also show that the optimal gradation component of the mixture consists of the gneiss as coarse aggregate and the limestone as fine aggregate. The use of hydrated lime can improve the moisture susceptibility of the mixtures containing gneiss aggregates.

Effects of Parameters Designed by Bailey Method on the Property of Porous Asphalt Mixture

2011 ◽  
Vol 374-377 ◽  
pp. 1414-1419
Author(s):  
Ming Ming Zhang ◽  
Pei Wen Hao
Keyword(s):  
Coarse Aggregate ◽  
Asphalt Mixture ◽  
Superior Performance ◽  
Unit Weight ◽  
Test Results ◽  
Moisture Susceptibility ◽  
Porous Asphalt ◽  
Coarse Aggregates ◽  
Air Void ◽  
The Relationship

Based on the Bailey method for aggregate grading design and evaluation, the parameter "reserved voidage" is used in porous asphalt method design. The paper studies the relationship between the three parameters (reserved voidage, blend by volume of the coarse aggregates totaling 100.0% and chosen unit weight of coarse aggregate) and the pavement performances, such as deformation, resistance at high temperature, low-temperature anti-cracking and moisture susceptibility of porous asphalt mixture. The test results indicate that the porous asphalt mixture designed by the modified Bailey Method is of the characteristics of air void easier to control and superior performance.

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