scholarly journals Prediction Model for Connected Voids Ratio of the Porous Asphalt Mixture

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Xiang Li ◽  
Zhaoyi He
Keyword(s):  
Prediction Model ◽  
Water Permeability ◽  
Equivalent Width ◽  
Asphalt Mixture ◽  
Material Design ◽  
Raw Material ◽  
Porous Asphalt ◽  
Viscosity Parameter ◽  
Passing Rate ◽  
The Difference

The practice showed that the difficulty to precisely predict the water permeability of the asphalt mixture by porosity creates the problem of the discrepancy between the material design and its function. And in the porous asphalt mixture, it is the connected voids ratio that truly bears the function of water permeability. However, there are many factors influencing the connected voids, and their influence laws remain to be known. Having analyzed the effects of different technical parameter on connected voids, 135°C rotation viscosity parameter was chosen in this paper to study the influences of properties of the asphalt mixture on connected voids. The equivalent width among framework gaps was quantified. The relation between the equivalent width, passing ratio of key sieve, and connected voids was discussed, and hence the prediction model for connected voids was established. The research showed that asphalt mixture with high 135°C rotation viscosity of asphalt had smaller connected voids, but the viscosity had less influence on connected voids ratio of asphalt mixture with larger equivalent width among framework gaps. The larger the equivalent width among framework gaps, the bigger the connected voids ratio. The passing rate of 2.36 mm sieve increased; both voids ratio and connected voids ratio became smaller and the difference value between them increased. Since the limitations of the composite specimens limited the prediction range, when the passing rate of 2.36 mm gradation was too small, there was a huge difference between the prediction value and the actual value. This model can predict the connected voids ratio under the stage of gradation design, thus saving the experiment time, shortening the design period, and providing some guidance to the adjustment of the raw material choosing and gradation.

scholarly journals Study on Compatibility and Rheological Properties of High-Viscosity Modified Asphalt Prepared from Low-Grade Asphalt

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3776 ◽  
Author(s):  
Mingliang Li ◽  
Feng Zeng ◽  
Ruigang Xu ◽  
Dongwei Cao ◽  
Jun Li
Keyword(s):  
High Temperature ◽  
Asphalt Mixture ◽  
Material Design ◽  
High Viscosity ◽  
Low Grade ◽  
Local Climate ◽  
Porous Asphalt ◽  
Modified Asphalt ◽  
Before And After ◽  
High Temperature Condition

High-viscosity modified asphalt is mainly used as a binder for porous asphalt in China and Japan. In order to meet the demand for using porous asphalt under high temperature condition in Africa, high-viscosity asphalt made from low-grade matrix asphalt, which is commonly used in Africa is investigated. Based on simulation of local climate in Africa, the suitable range of high viscosity additive content for different matrix asphalt was obtained by analyzing dynamic viscosity of the asphalt. Through PG high temperature grading, multi-stress repeated creep, accelerated fatigue, temperature sweep and other tests, changes of high temperature, anti-fatigue and anti-shear indicators before and after modification were compared and analyzed and effects of different matrix asphalt were also studied. Finally, considering engineering requirements, mixing and compaction temperatures of various high-viscosity modified asphalt were determined through study of viscosity-temperature characteristics. This research provides a support for preparation of high-viscosity modified asphalt and porous asphalt mixture by using low grade asphalt. The research achievements can help to guide the material design and application of porous asphalt in Africa and other high temperature areas.

scholarly journals Application of Biochar on the runoff purification performance of porous asphalt pavement

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Jiawen Liu ◽  
Hui Li ◽  
John Harvey ◽  
Hengji Zhang ◽  
Yu Tian
Keyword(s):  
Removal Rate ◽  
Low Impact Development ◽  
Asphalt Mixture ◽  
Raw Material ◽  
Nitrogen And Phosphorus ◽  
Porous Asphalt ◽  
Material Sources ◽  
Water Cleaning ◽  
Wide Range ◽  
Infiltration Test

Abstract Biochar is currently applied in many low-impact development measures, such as biofilters and filter strips. However, its application in permeable pavement is limited. Due to the wide range of raw material sources, biochar may also contain nutrients and heavy metals. Whether its leachate will cause contamination during application remains unknown. Based on the static leachate contamination test, this study first evaluated the leachate contamination risks of three types of biochar and porous asphalt mixture (PA) with three biochar fillers. Through the pavement infiltration test, the purification performance of PA with biochar fillers and filter layers was further analysed. The results show that biochar contains nitrogen and phosphorus, and the leaching contamination of coconut shell is the most obvious; when the biochar is applied as a filler in PA, the leaching contamination decreases, while the pollutant purification performance is not obvious; when 3−5 mm rice straw biochar is used as a filter layer, the removal rate of total suspended solids can be 100%, but it is accompanied by more serious nitrogen and phosphorus leaching, and the greater the thickness, the more serious the degree of leaching. Deionized water cleaning can remove the phosphates contained in biochar, but have little effect on nitrogen. Therefore, before the application of biochar, cleaning measures should be taken to minimize its leaching contamination.

SELISIH BIAYA PRODUKSI SEBAGAI ALAT PENGENDALIAN MANAJEMEN PT INDO PUSAKA BERAU

2019 ◽  
Vol 3 (02) ◽  
pp. 397
Author(s):  
SAFITRI NURHIDAYATI ◽  
RIZKI AMELYA SYAM
Keyword(s):  
Raw Materials ◽  
Field Research ◽  
Analytical Tool ◽  
Production Costs ◽  
Raw Material ◽  
Labor Costs ◽  
Material Costs ◽  
Library Research ◽  
The Difference ◽  
The Cost

This study aims to analyze whether the difference that occurs in the cost of raw materials, direct labor, and factory overhead costs between the standard costs and the actual costs in PLTU LATI is a difference that is favorable or unfavorable. Data collection techniques with field research and library research. The analytical tool used is the analysis of the difference in raw material costs, the difference in direct labor costs and the difference in factory overhead costs. The hypothesis in this study is that the difference allegedly occurs in the cost of raw materials, direct labor costs, and factory overhead costs at PT Indo Pusaka Berau Tanjung Redeb is a favorable difference. The results showed that the difference in the cost of producing MWh electricity at PT Indo Pusaka Berau Tanjung Redeb in 2018, namely the difference in the price of raw material costs Rp. 548,029.80, - is favorable, the difference in quantity of raw materials is Rp. 957,216,602, - is (favorable) , the difference in direct labor costs Rp 2,602,642,084, - is (unfavorable), and the difference in factory overhead costs Rp 8,807,051,422, - is (favorable) This shows that the difference in the overall production cost budget is favorable or profitable. This beneficial difference shows that the company is really able to reduce production costs optimally in 2018.  

scholarly journals Laboratory Investigation of Compaction Characteristics of Plant Recycled Hot-Mix Asphalt Mixture

2021 ◽  
Vol 13 (6) ◽  
pp. 3005
Author(s):  
Jiangang Yang ◽  
Chen Sun ◽  
Wenjie Tao ◽  
Jie Gao ◽  
Bocheng Huang ◽  
...  
Keyword(s):  
Regression Model ◽  
Hot Mix Asphalt ◽  
Orthogonal Experiment ◽  
Asphalt Mixture ◽  
Material Design ◽  
Void Content ◽  
Range Analysis ◽  
Aggregate Gradation ◽  
Compaction Characteristics ◽  
Compaction Energy

In this study, the compaction characteristics of recycled hot-mix asphalt (RHMA) were evaluated using the void content (VV), compaction energy index (CEI), slope of accumulated compaction energy (K), and lock point (LP). Then, the effects of the compaction parameters, including the gradation of the RHMA, reclaimed asphalt pavement (RAP) content, temperature of gyrations, and number of gyrations, on the compaction characteristics of RHMA were investigated. An orthogonal experiment was designed and the data collected were analyzed via range analysis; then, a regression model was generated relying on a quadratic polynomial. Furthermore, the regression model was used for the comparison and prediction of the mixture’s compactability during the material design. Finally, the compaction mechanism of RHMA was discussed from the perspective of the void content of RAP particles. The results showed that a finer aggregate gradation, a higher gyration temperature, a greater number of gyrations, and a higher RAP content were effective for increasing the compactability of RHMA. The range analysis results suggest that the gradation of RHMA has the greatest influence on compactability, followed by the RAP content. The RAP aggregate cannot diffuse to a new mixture completely, so the remained RAP particle reduces the void content of RHMA. Therefore, a higher RAP content up to 50% can help RHMA to achieve the designed void content with higher efficiency.

scholarly journals Experimental Study of Low Temperature Performance of Porous Asphalt Mixture

2021 ◽  
Vol 11 (9) ◽  
pp. 4029
Author(s):  
Jian Wang ◽  
Pui-Lam Ng ◽  
Yuhua Gong ◽  
Han Su ◽  
Jinsheng Du
Keyword(s):  
Low Temperature ◽  
Test Temperature ◽  
Asphalt Mixture ◽  
Aging Condition ◽  
Porous Asphalt ◽  
Bending Strain ◽  
Temperature Performance ◽  
Temperature Environment ◽  
Modifier Content ◽  
Low Temperature Performance

Porous asphalt mixture can be used as a road surface paving material with the remarkable advantage to prevent water accumulation and ponding. However, the performance of porous asphalt mixture in low temperature environment has not been thoroughly investigated, and this forms the subject of research in the present study. The mineral aggregate gradation of porous asphalt mixture was designed based on Bailey method, and the low temperature performance of porous asphalt mixture was studied by means of the low temperature bending test. The factors affecting the low temperature performance of porous asphalt mixture were analyzed through the orthogonal experimental design method, and the effects of porosity, modifier content, aging condition, and test temperature on the low temperature performance of porous asphalt mixture were evaluated. The results showed that the modifier content was the most important factor affecting the low temperature performance of porous asphalt mixture, followed by the test temperature, while the porosity and the aging condition were the least. Among the three performance evaluation indicators, namely the flexural tensile strength, maximum bending strain, and bending stiffness modulus, the maximum bending strain had the highest sensitivity to the porosity. It can be seen from the single factor influence test of porosity that there existed an approximately linear relationship between the maximum bending strain and the porosity of porous asphalt mixture, and the maximum bending strain decreased with increasing porosity. Furthermore, in order to ensure the good working performance of porous asphalt mixture in low temperature environment, the porosity should also satisfy the required limits of the maximum bending strain.

Sign in / Sign up

Export Citation Format

Share Document