scholarly journals Rapid-setting flowable fill performance in cold weather for airfield damage repair

2018 ◽  
Author(s):  
Lulu Edwards ◽  
William Carruth ◽  
Jeb Tingle ◽  
Isaac Howard
Keyword(s):  
Cold Weather ◽  
Rapid Setting ◽  
Damage Repair ◽  
Flowable Fill

Evaluation of geocell-reinforced backfill for airfield pavement repair

2021 ◽  
Author(s):  
Lyan Garcia ◽  
James Rowland ◽  
Jeb Tingle
Keyword(s):  
Field Experiments ◽  
Crushed Stone ◽  
Flight Operations ◽  
Damage Repair ◽  
Flowable Fill ◽  
Backfill Materials ◽  
Specific Material ◽  
Temporary Airfield ◽  
Weak Subgrades ◽  
Aircraft Loads

After an airfield has been attacked, temporary airfield pavement repairs should be accomplished quickly to restore flight operations. Often, the repairs are made with inadequate materials and insufficient manpower due to limited available resources. Legacy airfield damage repair (ADR) methods for repairing bomb damage consist of using bomb damage debris to fill the crater, followed by placement of crushed stone or rapid-setting flowable fill backfill with a foreign object debris (FOD) cover. While these backfill methods have provided successful results, they are heavily dependent on specific material and equipment resources that are not always readily available. Under emergency conditions, it is desirable to reduce the logistical burden while providing a suitable repair, especially in areas with weak subgrades. Geocells are cellular confinement systems of interconnected cells that can be used to reinforce geotechnical materials. The primary benefit of geocells is that lower quality backfill materials can be used instead of crushed stone to provide a temporary repair. This report summarizes a series of laboratory and field experiments performed to evaluate different geocell materials and geometries in combinations with a variety of soils to verify their effectiveness at supporting heavy aircraft loads. Results provide specific recommendations for using geocell technology for backfill reinforcement for emergency airfield repairs.

scholarly journals Long-Term Durability of Cold Weather Concrete : Phase II

2021 ◽  
Author(s):  
Benjamin E. Watts ◽  
Danielle E. Kennedy ◽  
Ethan W. Thomas ◽  
Andrew P. Bernier ◽  
Jared I. Oren
Keyword(s):  
Room Temperature ◽  
Cold Weather ◽  
Chemical Admixtures ◽  
Rapid Setting ◽  
Petrographic Examination ◽  
Active Research ◽  
Freeze Protection ◽  
Very High ◽  
Recent Laboratory

Recent laboratory results confirm that it is possible to protect concrete from freezing solely using chemical admixtures and indicate that the amount of admixture required may be significantly less than previously recommended. Researchers have also verified that admixture-based freeze protection can produce concrete that is durable to winter exposure for a minimum of 20 years, through petrographic examination of core specimens obtained from past field demonstrations. Freeze protection for concrete using chemical admixtures alone has been an area of active research for 3 decades; however, the most recent methodology recommends very high addition rates of accelerating and corrosion inhibiting admixtures, which result in significant challenges, including slump loss, rapid setting, and potentially excessive temperature rise. As part of a laboratory study, researchers systematically varied the dosage of freeze protection admixtures used in concrete cured in a 23 °F environment. Preliminary findings indicate that a 50% reduction in admixture dose maintained adequate freeze protection and resulted in compressive strengths exceeding those of room-temperature controls at 7 and 28 days. The combination of improved handling, reduced cost, and verified durability associated with the use of admixtures for freeze protection makes a compelling case for broader adoption of this technique in winter operations

Development of Ultra-Rapid Setting Construction Materials for Extremely Cold Regions Using Magnesia-Phosphate Cement

2014 ◽  
Vol 584-586 ◽  
pp. 1081-1084
Author(s):  
Hyun Woo Cho ◽  
Hyun Seop Shin ◽  
Jang Hwa Lee
Keyword(s):  
Low Temperature ◽  
Exothermic Reaction ◽  
Construction Materials ◽  
Frost Damage ◽  
Experimental Results ◽  
Cold Weather ◽  
Cold Regions ◽  
Ordinary Concrete ◽  
Arctic Regions ◽  
Rapid Setting

Because ordinary concrete cannot be hardened well under sub-zero temperatures, anti-freeze agents are typically added to prevent the frost damage and to ensure the proper hardening of concrete. With the advantage of a rapid exothermic reaction property, jet set concrete may be used as a cold weather concrete because it can reach the required strength before being damaged by cold weather. Recent studies are reported that magnesia-phosphate cement can be hardened very quickly and hydrated even in low temperature, which can be used as an alternative of severe cold weather concrete in arctic regions. This study developed the magnesia-phosphate cement that can be used in severe cold regions and suggested an appropriate mixture design from the experimental results.

Cold Weather Integrity Dig on a Scenic River, Northern Michigan

2015 ◽  
Author(s):  
Jay B. Bergman ◽  
Robert J. Schoneberger ◽  
Matthew A. Fournier
Keyword(s):  
Cold Weather ◽  
Northern Michigan

99. Characterization of Cold Weather Plumes from Jet Engine Start-UPS

2000 ◽  
Author(s):  
A. Armendariz ◽  
D. Leith ◽  
M. Boundy ◽  
R. Goodman ◽  
L. Smith
Keyword(s):  
Cold Weather ◽  
Jet Engine ◽  
Start Ups ◽  
Engine Start

Technology for Anticorrosive Protection of Steel Structures by Coatings Based on Rapid-Setting Bitumen-Latex Emulsion

2016 ◽  
Vol 12 (1) ◽  
pp. 28-35
Author(s):  
H.M. Nykyforchyn ◽  
◽  
V.A. Chervatyuk ◽  
V.I. Marukha ◽  
Z.V. Slobodyan ◽  
...  
Keyword(s):  
Steel Structures ◽  
Rapid Setting

Vulnerability of sweet cherry cultivars to continuous periods of spring frosts in Plovdiv, Bulgaria

2020 ◽  
Vol 12 (4) ◽  
pp. 348-352
Author(s):  
S. Malchev ◽  
S. Savchovska
Keyword(s):  
Sweet Cherry ◽  
Weather Conditions ◽  
Frost Damage ◽  
Cold Weather ◽  
Bud Burst ◽  
Intermediate Group ◽  
Air Temperatures ◽  
Wide Range ◽  
Group Form ◽  
Sweet Cherry Cultivars

Abstract. The periods with continuous freezing air temperatures reported during the spring of 2020 (13 incidents) affected a wide range of local and introduced sweet cherry cultivars in the region of Plovdiv. They vary from -0.6°C on March 02 to -4.9°C on March 16-17. The duration of influence of the lowest temperatures is 6 and 12 hours between March 16 and 17. The inspection of fruit buds and flowers was conducted twice (on March 26 and April 08) at different phenological stages after continuous waves of cold weather conditions alternated with high temperatures. During the phenological phase ‘bud burst’ (tight cluster or BBCH 55) some of the flowers in the buds did not develop further making the damage hardly detectable. The most damaged are hybrid El.28-21 (95.00%), ‘Van’ (91.89%) and ‘Bing’ (89.41%) and from the next group ‘Lapins’ (85.98%) and ‘Rosita’ (83.33%). A larger intermediate group form ‘Kossara’ (81.67%), ‘Rozalina’ (76.00%), ‘Sunburst’ (75.00%), ‘Bigarreau Burlat’ (69.11%) and ‘Kuklenska belitza’ (66.67%). Candidate-cultivar El.17-90 ‘Asparuh’ has the lowest frost damage values of 55.00% and El.17-37 ‘Tzvetina’ with damage of 50.60%.

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