Synthesis and Property of a Green Melting-Snow Additive for Asphalt Pavement

2014 ◽  
Vol 694 ◽  
pp. 85-89
Author(s):  
Chao Peng ◽  
Jian Ying Yu ◽  
Jing Dai ◽  
Zhi Jie Zhao ◽  
Jing Yi Fu ◽  
...  

Mg-Al Cl-layered double hydroxide (LDH) was prepared from Mg-Al CO32-LDH by the calcination recovery method. Energy dispersive spectroscopy (EDS) spectra proved that Cl-anions replaced CO32-anions in the LDH structure. Scanning electron microscopy (SEM) images showed that the platelet thickness of Mg-Al Cl-LDH were larger than those of Mg-Al CO32-LDH. This increase in the structural dimensions occurred because of that a larger quantity of monovalent Cl-anions had substituted divalent CO32-anions. The result of freezing temperature tests indicated that Mg-Al Cl-LDH is more effective than Mg-Al CO32-LDH in melting snow. Conductivities of immersion liquids testified that Cl-anions are restricted in asphalt mixtures by Mg-Al Cl-LDH without negatively affecting the surrounding environment and pavement. Snow melting rates for Mg-Al Cl-LDH before and after immersion did not change, indicating that rain did not weaken the effect of Mg-Al Cl-LDH on melting snow and thus did not pollute the environment.

2010 ◽  
Vol 24 (15n16) ◽  
pp. 3226-3229 ◽  
Author(s):  
AKIHIRO SHIMAMURA ◽  
MASASHI KURASHINA ◽  
EIJI KANEZAKI

The thermal behavior of Mg and Al layered double hydroxide with interlayer hydrogen phosphate (abb. as Mg / Al - HPO 4- LDH ) is investigated below 1273 K by means of XRD, TG-DTA, SEM and FT-IR. The basal spacing of Mg / Al - HPO 4- LDH decreases with increasing heating temperature stepwise in two stages; from 1.07 nm at 293 K to 0.85 nm at 333 K in the first stage and to 0.73 nm between 373 K and 443 K in the second one. The LDH becomes amorphous above 443 K until Mg 3 ( PO 4)2, MgO and MgAl 2 O 4 (spinel) appear at 1273 K. SEM images of the LDH show plate-like crystallites both before and after heating at 473 K.


2021 ◽  
Vol 21 (4) ◽  
pp. 169-177
Author(s):  
Kwanho Lee ◽  
Seongkyum Kim

Generally, the main causes of asphalt pavement damage are repeated loads and increased temperatures. The surrounding environment and material factors influence the degree of damage. In this study, the heat transfer characteristics with a change in the asphalt pavement thickness were analyzed. The sample types were the conventional dense asphalt mixture (WC-2), dense asphalt mixture containing 30% recycled aggregate (ReWC-2), and drainage asphalt mixture (PA-13). The mixtures were compacted using a rotary compactor. Thermal accumulation tests on samples with thicknesses of 3, 5, and 10 cm were performed. The values for the 10-cm-thick samples were 1.27 for WC-2, 1.28 for ReWC-2, and 0.91 for PA-13. The thermal conductivity tended to decrease as the pavement thickness increased. An experimental study on the heat transfer characteristics with varying thicknesses of asphalt pavement suitable for energy harvesting was conducted.


2021 ◽  
Vol 13 (13) ◽  
pp. 2613
Author(s):  
Nectaria Diamanti ◽  
A. Peter Annan ◽  
Steven R. Jackson ◽  
Dylan Klazinga

Density is one of the most important parameters in the construction of asphalt mixtures and pavement engineering. When a mixture is properly designed and compacted, it will contain enough air voids to prevent plastic deformation but will have low enough air void content to prevent water ingress and moisture damage. By mapping asphalt pavement density, areas with air void content outside of the acceptable range can be identified to predict its future life and performance. We describe a new instrument, the pavement density profiler (PDP) that has evolved from many years of making measurements of asphalt pavement properties. This instrument measures the electromagnetic (EM) wave impedance to infer the asphalt pavement density (or air void content) locally and over profiles.


2021 ◽  
Vol 304 ◽  
pp. 124653
Author(s):  
Osvaldo Muñoz-Cáceres ◽  
Aitor C. Raposeiras ◽  
Diana Movilla-Quesada ◽  
Daniel Castro-Fresno ◽  
Manuel Lagos-Varas ◽  
...  

2021 ◽  
Vol 1023 ◽  
pp. 121-126
Author(s):  
Van Bach Le ◽  
Van Phuc Le

Although small amount of binder in asphalt concrete mixture may commonly range from 3.5 to 5.5% of total mixture as per many international specifications, it has a significant impact on the total cost of pavement construction. Therefore, this paper investigated the effects of five carbon nanotubes contents of 0.05%, 0.1%, 0.15%, 0.2%, 0.25% by asphalt weight as an additive material for binder on performance characteristics of asphalt mixtures. Performance properties of CNTs modified asphalt mixtures were investigated through the Marshall stability (MS) test, indirect tensile (IDT) test, static modulus (SM) test, wheel tracking (WT) test. The results indicated that asphalt mixtures with CNT modified binder can improve both the rutting performance, IDT strength and marshall stability of tested asphalt mixtures significantly at higher percentages of carbon nanotubes. However, the issue that should be considered is the construction cost of asphalt pavement. Based on the asphalt pavement structural analysis and construction cost, it can be concluded that an optimum CNT content of 0.1% by asphalt weight may be used as additive for asphalt binder in asphalt mixtures.


2011 ◽  
Vol 105-107 ◽  
pp. 810-817 ◽  
Author(s):  
Rong Hui Zhang ◽  
Jia Liu ◽  
Jian Chao Huang ◽  
Yi Fu

To solve the high-temperature rutting problem of asphalt pavement, the old rubber of the tire rubber and plastic of general polyethylene waste composite modified asphalt mixture is proposed. The plastic and rubber compound particle was made by the rubber through efficient desulfurization additives, pre-swelling, twin-screw extrusion equipment. The particles mixed with the asphalt mixtures specimen preparation and the dynamic stability experiments, composite beam fatigue experiments, flexural tensile strength and modulus experiments and anti-reflective pavement cracks and other mechanical experiments are performed. The comparative data obtained by the rubber and plastic composited modified asphalt mixtures and SBS asphalt mixtures prove that the rubber and plastic composited modified asphalt mixtures have excellent rutting resistance and fatigue resistance.


Author(s):  
Anupama Bhardwaj ◽  
Jagtar Singh ◽  
Sonia Chaman ◽  
Amit Joshi

Objective: The objective of this study is to make sure biotreatment process used for treatment of dairy wastewater (DWW) is safe for human and its surrounding environment; microbes were evaluated for their antibiotic resistance profile against commonly prescribed antibiotics. Methods: Microbes were isolated using spread plating and streaking method and used to treat DWW. Reduction in organic load in DWW was determined by comparing physicochemical parameters (PCP) of DWW before and after treatment process. After selection of efficient microbial isolates, they were evaluated for their antibiotic resistance profile using antibiotic disc diffusion method. Results: In this work, 53 microbes were isolated from DWW, and these microbial isolates were screened for DWW degradation capacity by analyzing PCP. Four microbial isolates E3, E5, E11 (bacterial isolates) and F5 (fungal isolate) showed highest reduction in chemical oxygen demand (COD), biological oxygen demand (BOD), and dissolved oxygen (DO) were selected for profound degradation of DWW under optimized conditions. Efficient four microbial isolates individually performed better under anaerobic conditions by showing maximum reduction 84%, 75%, and 77% in COD, BOD, and DO, respectively. After 72 hrs of antibiotic susceptibility testing, E3 strain had shown 100%, E5 90%, E11 70%, and F5 80% susceptibility to antibiotics. Conclusion: The present study concluded that four microbial isolates had the potential of reducing the organic load of DWW along with lessor or negligible adverse effect on human or its surrounding environment and they appear to be most promising strains for treatment of DWW. 


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