De-icing Chemicals Research Articles

Multi-scale measurement of constitutive viscoelastic properties of bituminous composites considering moisture and deicing conditions

The use of salt and chemical deicers can cause significant damage to road infrastructures. This study investigates the impact of different deicers on the viscoelastic properties of mastic and asphalt mixtures, with a focus on characterizing their behavior at varying temperatures and loading frequencies. The samples were subjected to conditioning in solutions of distilled water, salt, Calcium Magnesium Acetate (CMA), and Potassium Acetate (KAc) at 60 °C for 96 h, followed by frequency sweep and dynamic modulus tests at different temperatures and loading frequencies. The results indicate that moisture conditioning with distilled water softens asphalt mixtures and mastic at low loading frequencies, while brine softens the former at low temperatures. Salt's high interaction with mixture aggregates cannot be ignored. CMA's effect on the fatigue behavior of mastic samples is highly dependent on loading frequency, while KAc increases stiffness at intermediate and high temperatures. All the deicers reduce resistance to rutting damage, with CMA having the most negative effect. Both the 2S2P1D and the generalized Maxwell model can well (R2 ≥ 0.90, Se/Sy ≤ 0.35) predict the viscoelastic properties of dry asphalt mixture. However, in the presence of distilled water and the deicers, asphalt mixture viscoelastic properties cannot be predicted according to asphalt mastic characteristics by implementing the homothety method which indicates different effects of distilled water and the deicers on various scales of bituminous composites.

Evaluation of the Effect of De-icing Chemicals on Performance of Airport Concrete Pavement under Freeze-Thaw Cycles

Weather conditions such as rainfall and freeze-thaw cycles affect the pavement performance of airports; therefore, methods such as using de-icing chemicals are considered in order to maintain the normal condition of the airport runway. In addition to the above factors, de-icing chemicals play an important role in pavement performance and the damage caused to it due to their chemical nature. Therefore, investigating the effect of de-icing chemicals and determining the appropriate material to maintain the airport's pavement is a priority for engineers. In this study, the effect of three de-icing chemicals, sodium chloride, potassium acetate, and ethylene glycol (at concentrations of 23.3%, 49%, and 69.07%, respectively) on skid resistance (The British Pendulum Test (BPT) and The Road Test Machine (RTM)) and the mechanical properties (Compressive Strength Test) of the concrete under Freezing and Thawing Cycle were investigated. The BPT test results showed that sodium chloride resulted in better skid resistance than other chemicals when the number of cycles is more than 100 cycles. This result was also obtained for all cycles in the RTM test. Also, ethylene glycol was not suitable for improving skid resistance based on BPT and RTM tests. Furthermore, the results of the compressive strength of concrete mixtures showed that the de-icing chemicals reduced the compressive strength of concrete mixtures. Based on all the results, sodium chloride had better results than other chemicals.

Impact of Airport De-Icing Chemicals and Freeze-Thaw on Rutting Resistance of Asphalt Mixture in Canada

Acetate-based ice control chemicals have been shown to have less environmental impact compared with traditional de-icing salts. However, their impact on the asphalt pavement’s performance has been underestimated and has drawn the attention of pavement engineers. This study was undertaken to evaluate the effect of de-icing chemicals (potassium acetate) and the freeze-thaw cycle on the rutting resistance of asphalt mixtures. Two types of airport pavement mixtures (AS and AB) and three roadway mixtures (HL3, HL3 HS, and HL1) were tested through the Hamburg wheel tracking test (HWTT) under three different treatments for the testing specimens: treated with potassium acetate solution, with one freeze-thaw cycle; and treated with potassium solution and one freeze-thaw cycle, respectively. The results show that potassium acetate solution and the freeze-thaw cycle can significantly affect the rutting resistance of all tested mixtures, and potassium acetate might have the potential to induce stripping damage on asphalt mixtures. A combination of de-icing treatment and the freeze-thaw cycle can potentially mitigate the stiffness compromise caused by their sole impact. Asphalt binder type, asphalt content, and different treatment methods have a statistical effect on the rutting resistance of asphalt mixture applied both on airside and roadway pavements.

Thermal and structural response of a pavement solar collector prototype

Thermal and structural response of a pavement solar collector prototype

Night icing prediction using vehicle-mounted pavement temperature sensor and atmospheric data

Faced with high accident rates on ice-covered roads at night, notifying road managers of the most dangerous locations would allow them the opportunity to treat the icy roads by applying de-icing chemicals. In addition, drivers can be better prepared for the impending danger. In this regard, this study developed a web-based night icing potential information system and a deep learning-based night icing forecasting model. Input data included pavement temperature, collected by patrol cars operating between 23:00 and 07:00 on a daily basis in the winter season, and atmospheric data provided by the Korea Meteorological Administration. For evaluating the forecasting model, baseline data were generated based on the physical principle that ice is formed when pavement temperature is negative and lower than the dew point temperature. The forecasting model was assessed using pavement temperature and atmospheric data obtained on a 40 km stretch of a rural highway, passing through a mountainous region in South Korea. As a result, the model showed favorable performances, with 94% and 90% accuracies for bridge and roadway segments, respectively. Considering the increasing emphasis on preventive maintenance, the developed forecasting model can be applied to a preventive anti-icing measure, in turn, increasing traffic safety on winter roads.

Effect of De-Icing Chemicals on Concrete Scaling: The Role of Storage Water.

This paper deals with the effect of the character of the water used for the water storage of concrete test specimens on the results of tests for resistance to de-icing chemicals. Two experiments were conducted to investigate the effect of the content of free CO2 in water and leaching of calcium hydroxide from concrete on the test results. In the first experiment, the resistance of mortars to water and de-icing chemicals was investigated. It was found that the character of the water storage, i.e., fresh water vs. previously used water, can significantly affect the test results. The second experiment focused on investigating the effect of the content of free CO2 in water on the test results. It was found that the content of free CO2 in the water can statistically significantly influence the test results. In conclusion, the paper shows that the character of the water used for water storage of concrete test specimens and the content of free CO2 in water are essential factors that can significantly affect the results of concrete resistance tests to de-icing chemicals. Further research is needed to understand these influences and their potential use to improve the resistance of concrete.

Modelling Plume Development with Annual Pulses of Contaminants Released from an Airport Runway to a Layered Aquifer, Evaluation of an In Situ Monitoring System

In cold climates, the use of de-icing chemicals in the winter can lead to groundwater contamination, especially when used in large quantities, such as at airports. Oslo Airport, Gardermoen, is situated on Norway’s largest rain-fed aquifer. Potassium formate is used to remove ice from runways and propylene glycol from airplanes; the organic parts are degradable. Most of the wells to monitor the spread of de-icing chemicals in the underlying aquifer have well screens near the groundwater level, while the runways and the source of de-icing chemicals are near the groundwater divides, where vertical flow is expected. The objective of this study is to demonstrate the importance of layers and time-varying recharge on the spreading of contaminant plumes in an aquifer near a groundwater divide. This is done with numerical modelling. The model results show increased vertical transport of the added tracer in the presence of horizontal layers, both continuous and discontinuous, in the aquifer. With certain distributions of hydraulic conductivity, Ks, we demonstrate that deeper monitoring wells are required. With the scenarios modelled here, time-varying recharge has a weaker effect on plume distribution. Measured concentrations of potassium and total organic carbon show the cyclic effect of seasonally varying recharge of contaminants, and an asymptotic accumulation of concentration over time, that is consistent with the model runs. In conclusion, groundwater monitoring systems near a groundwater divide should include multi-level samplers to ensure control of the vertical plume movement.

Geo-ecological aspects of the de-icing chemicals’ impact on the geological environment of urbanized areas

Geo-ecological aspects of the de-icing chemicals’ impact on the geological environment of urbanized areas

Insulated PEX-pipe loops for deicing on existing bridge deck using geothermal energy: Laboratory tests, modeling, and performance analyses

An external hydronic heating system utilizing geothermal energy is an innovative new method to de-ice in-service bridges that avoids detrimental environmental effects and damage to bridge deck structures stemming from chemical deicers and mechanical traction materials (e.g., sand). However, in these systems, the bottom surface of the bridge deck is usually fully covered by insulation materials and hence not accessible for visual bridge inspection. In this study, a new attached insulated, cross-linked polyethylene (PEX) pipe loop heating system is developed to heat existing bridges while maintaining a partly uncovered deck for visual inspection. The new loop consists of a PEX pipe, an aluminum plate, polyurethane foam insulation, and a high-density polyethylene jacket. Numerical simulations were first performed to determine the optimum shape and thickness of the insulation. Then the pre-made loop system was attached to the bottom surface of a concrete slab in a freezer box, where 62.3% of the slab bottom surface was covered by the system. A heated water bath was used to simulate the ground heat exchanger for heating the system. The heating tests were conducted at room temperatures of −2.78, −3.89, and −6.67 °C, with supplied water temperatures ranging from 24 to 45 °C. A 1-D steady-state thermal resistance model was then created to model the heat transfer processes and to estimate the slab surface temperatures. The results show that the deck surface heat flux fluctuated from 49.6 to 121.5 W/m2, depending on operating conditions and that an average of 16.3% of heat energy was transferred to the deck top surface. The results of misting tests indicate that the new system kept the bridge deck free from ice under mild winter conditions. These results demonstrate that the new insulated PEX pipe loop heating system is feasible for deicing existing bridges while minimizing the hindrance of bridge inspections.

Hydronic Road-Heating Systems: Environmental Performance and the Case of Ingolstadt Ramps

Abstract Snowfall and ice formation on road surface significantly impact the safety of driving conditions. To resolve this, every year salt and de-icing chemicals are sprinkled on roads. However, use of salts and snow ploughing have environmental as well as economical disadvantages. To resolve these problems, hydronic road heating systems are valid alternatives. Heat transfer fluid, i.e. mixture of ethanol and water, is pumped into a tubular circulation system under the asphalt. By this technology, the road and pavements shall stay ice-free even in times of snowfall and temperatures below the freezing point. The system can also be used to cool the asphalt in case of extreme heat, which – besides the heating effect – could also prevent road from damages in extreme summers. This study aims to compare the environmental impact of use of salts and road-heating system in terms of GHG emissions. To assess the environmental impact, an operational road heating system for a ramp in Ingolstadt, Germany, is considered. A cradle-to-grave analysis technique is used to determine the environmental effects based on a life-cycle assessment (LCA) framework. The analysis includes nine components solemnly responsible for hydronic heating of asphalt surface such as local heating pipe, insulation, pumps, and heat meters. Comparison is performed in terms of relative and total impact over 50-year lifetime of three heated ramps having 1989 m2 surface area in total. The results show that the asphalt and heating-circuit causes the major fraction (65 %) of overall GHG emissions, with total life-time emissions of 28.10 kg CO2 eq./m2 of heated surface. During an operational life of 50 years, road heating systems emit 18 % less CO2 eq./m2 as compared to the use of salts.

Impact of Airport De-Icing Chemicals and Freeze-Thaw on Rutting Resistance of Asphalt Mixture in Canada

Impact of Airport De-Icing Chemicals and Freeze-Thaw on Rutting Resistance of Asphalt Mixture in Canada

THEORETICAL APPROACHES TO RESEARCH THE ROLLING PROCESS OF THE DRIVEN WHEEL SIDE DRAWER ON A WINTER ROAD

The stability of the movement of motor vehicles in the cold season is ensured by the ability of car tires to create lateral reactions on winter roads. The lateral adhesion of the tire to the support surface is evaluated by its lateral withdrawal characteristics, which determine the coefficient of lateral adhesion and the critical angle of the tire withdrawal. With the use of chemical deicing materials, the coupling properties of tires have significantly deteriorated, especially in the lateral direction. The lack of knowledge about the processes of movement of a tire with lateral withdrawal on a winter road covered with chemical deicing materials determines the relevance of scientific research.
 The article discusses the non-stationary characteristics of the lateral withdrawal of Amtel NordMaster175/70R13 passenger friction tires, obtained from the results of their tests on a winter public road covered with rolled snow and sand-salt mixture. The graphs show that the use of sodium chloride reduces the lateral grip of friction tires and the stability of motor vehicles.
 Purpose – obtaining non-stationary characteristics of lateral withdrawal of passenger friction tires on a road covered with rolled snow and sand-salt mixture, and estimated parameters of lateral traction.
 Methodology: a road test method using the methodology and tire tester developed by the author to study the unsteady lateral withdrawal of automobile tires.
 Results: The unsteady characteristics of the lateral withdrawal of Amtel NordMaster 175/70R13 passenger friction tires were obtained, the coefficients of lateral adhesion and critical withdrawal angles were determined.
 Practical implications: the obtained results are necessary to correct the mathematical model that allows performing an analytical study of the processes of lateral withdrawal of automobile tires on roads with winter slipperiness.

Microwave heating and deicing efficiency for asphalt concrete with SiC–Fe3O4 microwave enhanced functional layer

Traditional deicing methods such as manual deicing, infrared heating deicing, chemical deicing might bring serious environmental pollution and energy consumption. Microwave heating deicing technology with high microwave energy utilization efficiency and environmental protection has been widely studied. But the microwave heating deicing efficiency still cannot meet the practical application requirement at present. In order to improve the microwave deicing efficiency, the asphalt concrete with microwave enhanced functional layer (MEFL) and control specimens (asphalt concrete without MEFL) were designed. In the meanwhile, the effect of SiC–Fe3O4 content and thickness of MEFL on microwave heating efficiency (MHE) and ice-thawing time were studied. Moreover, the influence of initial temperature and ice layer thickness on ice-thawing time were also evaluated. Finally, the energy utilization efficiency of MEFL was calculated. Results show that the SiC–Fe3O4 content in MEFL had a positive effect on MHE and ice-thawing time. The MHE and ice-thawing time of 28.6% SiC–Fe3O4 were 2.42 times and 6.2 times shorter than that of control specimens, respectively. But the MEFL thickness had a negative effect on MHE and ice-thawing time. The ice-thawing time of MEFL with −15 °C initial temperature was 46s. it was increased about 1.7 times in contrast to −5 °C. In addition, the thicker ice layer thickness might increase the ice-thawing time. The ice-thawing time of 30 mm ice layer was 13s longer than that of the 10 mm ice layer. The microwave energy utilization efficiency of 10 mm MEFL could reach 79.21%. Overall, the MEFL can significantly improve the MHE and deicing efficiency of asphalt concrete.

Is the Use of Road Salt and Chemical Deicers Worth the Costs? A Call for Environmentally Sustainable Winter Road Operations

The use of road salt and chemical deicers to control the accumulation of snow and ice on paved transportation surfaces has increased significantly over the decades. Estimates indicate that, each year, 60 million metric tons of salt alone is used globally for deicing. Deicing roadways and parking areas does provide an important service. It helps keep roads and parking areas navigable during snow and ice storms, reduces accidents and injuries and mitigates potentially significant economic losses to local, state, and regional economies due to closed roadways. But benefits do not come without fiscal and environmental costs. Extensive reliance on salts and harmful chemicals calls for the development and wide-spread use of environmentally sustainable and economically feasible alternatives.

Experimental and theoretical characterization of electrodes on electrical and thermal performance of electrically conductive concrete

Transportation agencies regularly seek innovative, cost-effective, and environmentally-friendly approaches to help manage winter maintenance operations during snow and ice events. The use of an electrically-conductive concrete (ECON) heated pavement system (HPS) is a smart and promising alternative to conventional snow and ice removal methods using de-icing chemicals and snow-removal equipment. ECON is made electrically conductive by introducing conductive agents into the concrete mix and applying electrical current through electrodes embedded in the ECON layer. This study investigates the influence of electrode size and geometry on the resistive heating performance of ECON HPS and identifies the most electrically and thermally-efficient type of electrode through experimental testing and theoretical analysis. Electrode performance was investigated in water, prototype ECON slabs, and through development of a finite-element model, and good agreement was found between the results obtained from these three evaluation methods. A theoretical formulation between thermal performance and electrical and material properties in ECON HPS was first developed. Testing electrodes in water was then found to be a quick, non-destructive, and cost-effective alternative method for monitoring thermal performance of electrodes. Finally, electrode surface contact area was identified as the dominant electrode characteristic with respect to influencing temperature increase. Cost and energy analysis for each electrode type showed that smaller-diameter electrodes exhibited higher cost-effectiveness, and conversely, larger diameter electrodes were found to have higher energy-conversion efficiency. The results of this work will provide guidance for choosing the most cost-effective and optimized type of electrode for design and construction of a large-scale ECON HPS.

Rf-Sputtered Teflon®-Modified Superhydrophobic Nanostructured Titanium Dioxide Coating on Aluminum Alloy for Icephobic Applications

Icing on surfaces such as cables or high-voltage insulators may often lead to severe safety issues such as power outages in cold winter conditions. Conventional methods used to tackle such icing problems include mechanical deicing, where the ice is scraped or broken, and chemical deicing, where deicers such as ethylene glycol are used. However, the best approach to addressing these issues is to prevent ice formation in the first place. Research in the past few decades have shown hydrophobic and superhydrophobic surfaces to be effective in reducing ice adhesion. We used the concept of water repellency to turn an aluminum surface superhydrophobic to minimize ice adhesion on these surfaces. However, to render these surfaces also applicable to insulating surfaces, we also demonstrated the adaptability of the concept on a low dielectric oxide, TiO2, to an aluminum surface with icephobic properties. This work demonstrates the importance of the coexistence of rough nanostructures as well as low-surface-energy compositions on a surface to make it superhydrophobic and icephobic and is applicable on metals and insulating surfaces.

Can calorimetry be used to measure the melting rate of deicers?

Chemical deicers are used in winter maintenance of roads and runways to melt ice and restore a bare pavement. The melting rate of these deicers is a fundamental performance factor, but good test methods to quantify the melting rate are still lacking. In this study, we present a method to measure the melting rate with calorimetry. The method provides a good control over heat fluxes and mixing which are crucial factors for the melting. In addition, it has an advantage of testing a deicer ‘as received’ without any sample handling prior to the test. The results showed that the melting rate of CaCl2 and MgCl2 can be clearly distinguished from NaCl. Solving the heat balance for solid deicers requires the deicer concentration in the meltwater to account for the enthalpy of dissolution. The freeze point and solubility concentrations set the physical limits on concentration and were used to assess the uncertainty due to unknown concentration. The extent of the uncertainty did not allow for a distinction between CaCl2 and MgCl2. This showed the need for an improved assumption scheme based on direct measurements. To represent a non-linear melting rate, different single-number metrics were investigated. The time it takes to reach 75% of the melting capacity gave the best characterization of the melting performance.

Experimental study of deicing chemical redistribution and moisture mass transfer in highway subsoils during the unidirectional freezing

Deicing chemicals, when applied to pavement surfaces, occasionally deposited on the ground beyond the road pavement, thus lead to their accumulation in roadside soils and producing secondary salinisation of the ground water. In order to explore moisture and chemical mass transfer in highway subsoils during the winter period, 9 non-saline soil samples of 1 m length were subject to simultaneously freeze–thaw cycles with freezing rate 2 °C/day. To monitor the dependence of mass transfer from the soil density, each further column was packed with increased dry density than the previous one and supplied with 22 g/L of NaCl solution from the base.The results show that soil columns with loose density were consolidated throughout the sample length with the maximum in its lower part. Whilst in the dense soil samples, only the top 10 cm was loosened and attracted a large amount of water to form ice lenses. Chemical mass transfer to the freezing front was observed along the entire length of the samples regardless of density and void ratio. The concentration of de-icing chemicals in the pore water exceeded the supplied solution by 2–2.5 times at the capillary raise zone. In this study, chemical mass transfer is considered in terms of the driving forces and the system equilibrium. The driving force was explained as a cryosuction force, effected to the hygroscopic water in a liquid state with dissolved de-icing chemical ions in it, which migrated towards the freezing front. The continuous secondary salinisation, lasting in the highway subsoils for years, requires an accurate protection as the use of plastic membrane or silicone gel insulation.

Resistance of Concrete with Surface Treatment against Chemical Deicing Agents

The paper presents the results of measurement of resistance of concrete with surface treatment against water with deicing chemicals. Surface treatment of the test specimens was performed by sandblasting using steel balls. The effect of sandblasting was measured on normal strength aerated concrete (NC) and high strength concrete (UUHPC). Aerated concrete gains its resistance to water with deicing chemicals mainly due to its pores structures, while UUHPC due to the low porosity and low water absorption of the cement matrix. The sandblasting of the specimens simulated the required surface finish or mechanical deterioration of the concrete.

Fatigue behavior of GFRP-reinforced ECC link slabs under variable stress levels and number of cycles

Glass Fibre Reinforced Polymer (GFRP) bars have been used in the Province of Ontario as top layer of bridge deck reinforcement near surfaces exposed to de-icing chemicals. The intent of replacing deck reinforcements with GFRP is to mitigate negative effects of conventional steel rebar corrosion. Furthermore, the development of Engineered Cementitious Composite (ECC) with inherent crack width control and strain-hardening tensile behaviour for link slab application provides design engineers with a new effective way to construct joint-free bridge decks with improved durability. This paper presents experimental investigation of ECC-link slabs reinforced with sand-coated GFRP bars. The link slab specimens were subjected to variable mean fatigue stress levels of up to 55% load capacity and fatigue cycles of up to 1 million, followed by post-fatigue monotonic loading to failure. Link slab load–deflection, stiffness degradation, end rotation, GFRP and ECC strains, crack development, failure modes, energy absorbing capacity, and ductility were determined. Results were then compared with companion steel-reinforced ECC link slabs in the literature to quantify benefits of using GFRP bars. Experimental results showed that GFRP-reinforced link slabs failure by concrete crushing due to high rupture strength of GFRP, whereas steel-reinforced link slabs failed by rebar yielding. Besides exhibiting improved overall strength, the GFRP reinforced ECC link slabs showed greater post-fatigue residual rotational capacity, lower rate of stiffness degradation, enhanced post-fatigue retention of energy absorbing capacity.