Providing Sufficient Void Space for Asphalt Cement: Relationship of Mineral Aggregate Voids and Aggregate Gradation

2009 ◽  
pp. 225-225-27 ◽  
Author(s):  
GA Huber ◽  
TS Shuler
Keyword(s):  
Void Space ◽  
Aggregate Gradation ◽  
Mineral Aggregate ◽  
Asphalt Cement ◽  
Relationship Of

scholarly journals Strength and Micro-Mechanism Analysis of Cement-Emulsified Asphalt Cold Recycled Mixture

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 128 ◽  
Author(s):  
Yuhui Pi ◽  
Yan Li ◽  
Yingxing Pi ◽  
Zhe Huang ◽  
Zhe Li
Keyword(s):  
Raw Materials ◽  
Asphalt Binder ◽  
Microscopic Analysis ◽  
Hydration Product ◽  
Mechanism Analysis ◽  
Recycled Asphalt ◽  
Aggregate Gradation ◽  
Asphalt Cement ◽  
Emulsified Asphalt ◽  
Cementing Material

The strength of EACRM (emulsified asphalt cold recycled mixture) is closely related to the properties and proportion of raw materials. In this paper, the strength formation mechanism of EACRM was first studied through microscopic analysis, and the influence regular of aggregate gradation, emulsified asphalt, water consumption, cement consumption, and other factors on its strength was analyzed through a series of laboratory tests. The analysis results show that the asphalt binder plays the role of cementing material in cement emulsified asphalt mortar. The combination of cement and emulsified asphalt is a physical combination. The hydration product not only increases the viscosity of asphalt cement, but also makes the surface of asphalt cement become uneven, which increases the adhesion area with the aggregate. Therefore, the microstructure of the interface between mortar and aggregate is improved. The bonding force of the interface and the mechanical properties of concrete are improved. Due to the influence of recycled asphalt pavement (RAP) materials, the excessive amount of emulsified asphalt and cement are not conducive to improve the strength of cold recycled mixture. Through experiments, the optimal amount of emulsified asphalt and cement is determined as 2.9% and 1.5%, respectively, for the RAP materials. At the same time, improving the performance of emulsified asphalt and adding quicklime and organic activator are also helpful to improve the strength of a cold recycled mixture.

Composite Dielectric Model of Asphalt Mixtures Considering Mineral Aggregate Gradation

2019 ◽  
Vol 31 (6) ◽  
pp. 04019091 ◽  
Author(s):  
Yingying Zhai ◽  
Bei Zhang ◽  
Fuming Wang ◽  
Yanhui Zhong ◽  
Xiaolong Li
Keyword(s):  
Asphalt Mixtures ◽  
Aggregate Gradation ◽  
Mineral Aggregate ◽  
Dielectric Model

Minimum Voids in Mineral Aggregate in Hot-Mix Asphalt Based on Gradation and Volumetric Properties

1996 ◽  
Vol 1545 (1) ◽  
pp. 75-79 ◽  
Author(s):  
John A. Hinrichsen ◽  
John Heggen
Keyword(s):  
Hot Mix Asphalt ◽  
Heavy Traffic ◽  
Field Application ◽  
Mix Design ◽  
Volumetric Properties ◽  
Aggregate Gradation ◽  
Mineral Aggregate ◽  
Traffic Loads ◽  
Recent Developments ◽  
Asphalt Mix

The use of voids in mineral aggregate (VMA) criteria for proper mix design of hot-mix asphalt is a time-honored and fairly successful tool. Recent developments in the field of asphalt mix design have encouraged the use of mixtures with a coarse aggregate structure to resist the effect of heavy traffic loads. By using the equations presented, which account for both aggregate gradation and the volumetric properties of the materials, the mix designer is able to judge the proper VMA requirement for each unique blend of materials. By applying the new equations, the most economical mix may be selected without great risk of reduced durability. Supporting data from field application are presented to illustrate the use of the equations.

Prediction of Asphalt Cement Content of Compacted Hot-Mix Asphalt Specimens Using Nuclear Gauges

1996 ◽  
Vol 1545 (1) ◽  
pp. 169-177
Author(s):  
Iyad A. Alattar ◽  
Imad L. Al-Qadi
Keyword(s):  
Moisture Content ◽  
Hot Mix Asphalt ◽  
Extraction Methods ◽  
Void Content ◽  
Study Program ◽  
Aggregate Gradation ◽  
Air Voids ◽  
Asphalt Cement ◽  
Specimen Weight ◽  
A New Technique

Determining asphalt cement (AC) content of hot-mix asphalt (HMA) for quality control/quality assurance using extraction methods is a lengthy, time-consuming, and hazardous process. A demand for a faster and safer method led to the development of different nuclear gauges capable of predicting the AC content of HMA samples. Measuring the AC content of compacted specimens by nuclear gauges is a new technique whose feasibility was evaluated. A total of 216 Marshall compacted specimens were cast and tested in an attempt to develop correction models. The study program investigated the effect of various HMA parameters on the measured AC content, including aggregate gradation and type, air void content, moisture content, AC content, and specimen weight. Specimens were prepared at two different mix design formulas using AC-30 and compacted at two different compaction efforts to investigate the effect of air voids. Specimens (1200 g each) used for calibration were prepared at 3 to 7 percent AC content, whereas specimens prepared for measurements were prepared at 4 to 6 percent. Quartzite and diabase aggregate were used as open and dense graded in prepared mixes. Three levels of moisture content in HMA were evaluated. Different calibration models were developed for different asphaltic mixtures. The evaluated nuclear gauge for measuring AC content for compacted HMA specimens produced satisfactory results when the parameters of tested and calibration parameters were the same. The study found that specimen weight is the most significant factor. Other parameters have different degrees of influence on the measured AC content. Statistical models were developed to correct for the evaluated parameters.

The Design and Case Study of Pervious Concrete Materials

2011 ◽  
Vol 287-290 ◽  
pp. 781-784
Author(s):  
Chao Lung Hwang ◽  
Chun Tsun Chen ◽  
Hsiu Lung Huang ◽  
Sheng Szu Peng ◽  
Le Anh Tuan Bui ◽  
...  
Keyword(s):  
Void Ratio ◽  
Aggregate Size ◽  
Data Bank ◽  
Pervious Concrete ◽  
Fine Aggregate ◽  
Aggregate Gradation ◽  
Local Code ◽  
Relationship Of ◽  
The Relationship

This study is mainly focused on the design and application of pervious concrete material to pavement and growing plant. The test results show: 1. Addition of fine aggregate obtains better binder quality. 2. Both small aggregate size and good aggregate gradation improve strength, but reduce void ratio and permeability. 3. A data bank of the relationship of the strength, the void ratio and the permeability of pervious concrete was built. 4. A practice case study of pavement demonstrates excellent permeability comparing to the local code and good quality as well as grass growing normally.

Discrete Element Simulation and Analysis for Max Density Curve Theory of Mineral Aggregate Mixtures

2014 ◽  
Vol 668-669 ◽  
pp. 12-16 ◽  
Author(s):  
Jia Xi Deng ◽  
Xiao Dong Zhou ◽  
Ya Ting Huang ◽  
Yu Liu ◽  
Wei Min Fan
Keyword(s):  
Model Parameters ◽  
Aggregate Gradation ◽  
Mineral Aggregate ◽  
Density Curve ◽  
Element Simulation ◽  
Pavement Engineering ◽  
Mineral Mixture ◽  
Maximum Particle ◽  
Curve Theory ◽  
Mineral Mixtures

In highway pavement engineering, mineral aggregate gradation is a key consideration in mixture design. The max density curve theory is one of the most popularly-used methods to design mineral mixture gradation. The main objective of this research is to present a numerical method for investigating impacts of mineral aggregate properties on model parameters of the max density curve theory. Through this study it was found that the maximum particle size gave an important impact on the model parameters, even though the model parameter n is around 0.45 for popularly-used mineral mixtures.

A New Formula of Voids in the Mineral Aggregate (VMA) of Hot Mix Asphalt (HMA) and its Application

2010 ◽  
Vol 150-151 ◽  
pp. 1158-1162
Author(s):  
Shu Tang Liu ◽  
Chang Shun Shao ◽  
Wei Dong Cao ◽  
Xiao Liu
Keyword(s):  
Design Process ◽  
Empirical Equation ◽  
Hot Mix Asphalt ◽  
Selection Index ◽  
Volume Index ◽  
Aggregate Gradation ◽  
Mineral Aggregate ◽  
Air Voids ◽  
Asphalt Content ◽  
New Formula

Voids in the mineral aggregate (VMA) is an important volume index for hot mix asphalt (HMA). In the popular HMA design methods such as Superpave system and Marshall Method an accurately calculated VMA is a crucial selection index for the aggregate gradation design. In this article a new formula for calculating VMA is established from the mathematic deduction based on the air voids and traditional VMA formulas. The new built VMA formula can be used to examine the result of the existing empirical equation in the aggregate gradation design process of Superpave. In fact, when the estimated asphalt content is determined according to the initial asphalt content the new formula can completely replace the empirical one for estimating VMA, offering conveniences to calculating.

scholarly journals Effect of Gradation Variability on Volume Parameter and Key Performances of HMA

2021 ◽  
Vol 7 ◽  
Author(s):  
Shutang Liu ◽  
Lin Zhu ◽  
Huiqin Zhang ◽  
Tao Liu ◽  
Ping Ji ◽  
...  
Keyword(s):  
Design Theory ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Fine Aggregate ◽  
Aggregate Gradation ◽  
Mineral Aggregate ◽  
Air Voids ◽  
Pavement Engineering ◽  
Asphalt Content ◽  
Main Component

The graded mineral aggregate composed of coarse aggregate, fine aggregate, and mineral powder is the main component of hot asphalt mixture (HMA), and it occupies a mass ratio of more than 95% in HMA. The gradation variability of mineral aggregate is frequently an unavoidable problem in the construction of asphalt pavement engineering. In order to investigate the effect of gradation variability on the volume parameters and key performances of HMA, the asphalt concrete with a nominal maximum particle size of 20 mm (AC20) was selected as the research carrier. Firstly, a benchmark mineral aggregate gradation (BMAG) was designed based on the theory of dense skeleton gradation presented in the paper. Secondly, six types of HMA (that is, AC20) with variable gradations were also determined and all the specimens were prepared by rotary compaction process with the same optimum asphalt content (gradation varies but asphalt content remains the same), and finally based on asphalt pavement analyzer, the performances of all the specimens of each gradation were tested. The results show that, compared with the BMAG-HMA, the volume parameters such as air voids, voids in mineral aggregate, and voids filled with asphalt of the variable-graded HMA change in different directions, but the water stability and high-temperature performance both degrade greatly. The experimental results also show the feasibility and effectiveness of the dense skeleton gradation design theory adopted in this study.

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