Quantitative Assessments of Crack Sealing Benefits by 3D Laser Technology

Author(s):  
Zhongyu Yang ◽  
Xinyi Zhang ◽  
Yichang (James) Tsai ◽  
Zhaohua Wang

Crack sealing is one of the most commonly used methods to preserve asphalt pavements. However, quantification of crack sealing benefits (or the long-term delaying effects of crack sealing on crack propagation) remains unavailable because field crack lengths could not be measured accurately and efficiently. In this study, 3D laser technology is proposed to measure and compare the growth of crack lengths between sealed and non-sealed pavement sections and, for the first time, to accurately and efficiently quantify the crack sealing benefits. To validate the proposed method and find adequate treatment timing (or conditions), nine field sites in Georgia, U.S., with different pavement pre-treatment conditions and roadway environmental factors were monitored over 3 years from December 2016 to September 2019. The study results showed that crack sealing can retard crack growth by 40%–128%, and such delaying effects are more significant under better pavement pre-treatment conditions. The findings suggest that transportation agencies can prolong the service life of pavements by applying crack sealing before the pavement condition becomes poor. In addition, this work has been proved to be very valuable for transportation agencies to determine the best timing and treatment criteria for crack sealing.

2007 ◽  
Vol 34 (4) ◽  
pp. 505-512 ◽  
Author(s):  
Yetkin Yildirim

One of the most important components of pavement maintenance has been the sealing of cracks. The most commonly used materials for crack sealing are hot-pour sealants, such as hot rubber asphalt. However, this material can be hazardous at high operating temperatures and is more likely to be picked up by vehicle tires if the sealant is not sufficiently adhered to the pavement. Thus, cold-pour sealants have been considered as an alternative for crack sealing purposes. This study aims to compare the performance of hot-pour rubber asphalt crack sealant and cold-pour asphalt emulsion crack sealant in five different Texas districts that experience different weather conditions. The comparison includes seven different crack sealants: three cold pour and four hot pour. Five different roads in five districts were selected for comparison of the sealants. The field study results indicate that hot-pour sealants performed better than cold-pour sealants.Key words: sealants, emulsified crack sealants, crack sealing, asphalt pavements.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vahideh Yari ◽  
Zeynab Roein ◽  
Atefeh Sabouri

AbstractThe Anemone genus is a tuberous geophyte which undergoes a dormancy period during unfavorable environmental conditions for growth. Five species of the Anemone genus naturally grow in several regions of Iran. The diverse uses of Anemone in gardens for landscaping, cut flowers, and potted plants indicate its high ornamental potential. Its dormancy and flowering are influenced by various factors. The present paper was conducted to explore the flowering behavior of Anemone accessions in response to different pre-treatments. For this purpose, tubers of 18 Anemone accessions (A. coronaria and A. biflora) were collected from natural regions of six provinces in Iran. These tubers were subjected to different conditions of non-chilling (20 °C, 90 days), chilling (4 °C, 90 days), GA3 (150 mgL-1; 24 h), and 5-azaCitidine (5-azaC; 40 µM; 24 h) prior to the cultivation. Most of the accessions were able to enter the flowering stage without chilling. The shortest period for the sprouting of tubers (16.89 ± 7.83 days) belonged to 5-azaC pre-treatment. In addition, this treatment accelerated the flowering time (about 30 days earlier) and diameter of the stem, bud, and flower. Morphological characteristics, such as stem height, number of leaves, bud, and petal and the longevity of flowers on the plant were significantly affected by GA3 pre-treatment. Our results indicated a positive correlation between flower length, stem height, and stem diameter with flower longevity under different pre-treatment conditions. The present study demonstrated that accessions Anm3, Anm12, and Anm18 had ornamental values higher than the population mean across four conditions.


2012 ◽  
Vol 65 (9) ◽  
pp. 1684-1691 ◽  
Author(s):  
G. Farabegoli ◽  
A. Chiavola ◽  
E. Rolle

The olive-oil extraction industry is an economically important activity for many countries of the Mediterranean Sea area, with Spain, Greece and Italy being the major producers. This activity, however, may represent a serious environmental problem due to the discharge of highly polluted effluents, usually referred to as ‘olive mill wastewaters’ (OMWs). They are characterized by high values of chemical oxygen demand (COD) (80–300 g/L), lipids, total polyphenols (TPP), tannins and other substances difficult to degrade. An adequate treatment before discharging is therefore required to reduce the pollutant load. The aim of the present paper was to evaluate performances of a biological process in a sequencing batch reactor (SBR) fed with pre-treated OMWs. Pre-treatment consisted of a combined acid cracking (AC) and granular activated carbon (GAC) adsorption process. The efficiency of the system was compared with that of an identical SBR fed with the raw wastewater only diluted. Combined AC and GAC adsorption was chosen to be used prior to the following biological process due to its capability of providing high removal efficiencies of COD and TPP and also appreciable improvement of biodegradability. Comparing results obtained with different influents showed that best performances of the SBR were obtained by feeding it with raw diluted OMWs (dOMWs) and at the lowest dilution ratio (1:25): in this case, the removal efficiencies were 90 and 76%, as average, for COD and TPP, respectively. Feeding the SBR with either the pre-treated or the raw dOMWs at 1:50 gave very similar values of COD reduction (74%); however, an improvement of the TPP removal was observed in the former case.


2018 ◽  
Vol 10 (3) ◽  
pp. 223-232
Author(s):  
G.J. Fadimu ◽  
L.O. Sanni ◽  
A.A. Adebowale ◽  
S.O. Kareem ◽  
O.P. Sobukola ◽  
...  

2001 ◽  
Vol 1 (4) ◽  
pp. 169-176
Author(s):  
K.H. Carlson ◽  
W.H. Bellamy

Recycling treatment, plant waste streams has become an important issue and the EPA is currently developing a rule for controlling and potentially limiting these streams. The impact to the overall treatment process and the relative risk of various recycle streams can be evaluated with a materials balance model of a treatment plant. A steady-state materials balance model was developed and applied to the recycle of backwash waste water, clarifier sludge supernatant and sludge dewatering supernatant. Recycling backwash water reduced the plant treatment effectiveness from 3.0 log to 2.95 log removal when the recycle stream was treated (0.5 log removal) and 2.84 log removal when not treated. Recycling clarifier sludge supernatant resulted in a reduction of performance from 3.0 log to 2.78 log removal with adequate treatment (0.5 log removal) and 1.95 log removal with inadequate treatment (10% removal). The model was used to identify vulnerable treatment conditions. Conventional treatment with a poorly operated or upset clarifier was identified as a significant risk with the overall treatment effectiveness decreasing from 3.0 to 2.3 log removal.


2020 ◽  
Vol 71 (1) ◽  
pp. 19-27
Author(s):  
Günay Özbay ◽  
Caglar Cekic ◽  
Muhammad Syarhabil Ahmad ◽  
Erkan Sami Kokten

In the present study, bio-oil produced from vacuum pyrolysis of woody biomass has been investigated as a source of chemical feedstock. Bio-based resins were produced using the bio- oil with phenol substitutions ranging from 10 to 30 wt%. The conventional GC/MS analysis was carried out for the evaluation of the chemical composition of bio-oil. TGA, DSC and FT-IR analyses were used in order to characterize the bio-oil-phenol-formaldehyde (BPF) resins. The bonding quality of wood samples bonded with the BPF resins was investigated under different pre-treatment conditions. The highest shear strength was observed for the control samples bonded with the laboratory PF resin. As the amount of bio-oil was increased up to 30 wt%, the shear strength of the samples decreased from 12.08 to 11.76 N/mm2. The bonding performance was not negatively affected by the combination of bio-oil under dry conditions. According to TS EN 12765 standard, the relevant performance requirements for bonded samples under dry conditions must be at least 10 N/mm2. Relating to the standard, all samples bonded with BPF resins obtained the requirements for durability class C1. Under wet conditions, the bonding performance was negatively affected by the addition of bio-oil. However, the BPF resins fulfilled the durability requirements for C1, C2, and C3 specified in EN 12765 (2002).


2019 ◽  
Vol 13 (1) ◽  
pp. 271-285 ◽  
Author(s):  
Emily T. Kostas ◽  
Daniel A. White ◽  
David J. Cook

Abstract This study describes the method development for bioethanol production from three species of seaweed. Laminaria digitata, Ulva lactuca and for the first time Dilsea carnosa were used as representatives of brown, green and red species of seaweed, respectively. Acid thermo-chemical and entirely aqueous (water) based pre-treatments were evaluated, using a range of sulphuric acid concentrations (0.125–2.5 M) and solids loading contents (5–25 % [w/v]; biomass: reactant) and different reaction times (5–30 min), with the aim of maximising the release of glucose following enzyme hydrolysis. A pre-treatment step for each of the three seaweeds was required and pre-treatment conditions were found to be specific to each seaweed species. Dilsea carnosa and U. lactuca were more suited with an aqueous (water-based) pre-treatment (yielding 125.0 and 360.0 mg of glucose/g of pre-treated seaweed, respectively), yet interestingly non pre-treated D. carnosa yielded 106.4 g g−1 glucose. Laminaria digitata required a dilute acid thermo-chemical pre-treatment in order to liberate maximal glucose yields (218.9 mg glucose/g pre-treated seaweed). Fermentations with S. cerevisiae NCYC2592 of the generated hydrolysates gave ethanol yields of 5.4 g L−1, 7.8 g L−1 and 3.2 g L−1 from D. carnosa, U. lactuca and L. digitata, respectively. This study highlighted that entirely aqueous based pre-treatments are effective for seaweed biomass, yet bioethanol production alone may not make such bio-processes economically viable at large scale.


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