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An Experimental Study on the Effectiveness of Anti-icing Operations for Snow and Ice 1

Control of Parking Lots and Sidewalks 2

3

4

S M Kamal Hossain 5

(Corresponding Author) 6

Ph.D. Student and Research Assistant 7

Department of Civil & Environmental Engineering, 8

University of Waterloo 9

Waterloo, ON, N2L 3G1 10

Email: [email protected] 11

12

Dr. Liping Fu, Professor 13

Department of Civil & Environmental Engineering, University of Waterloo 14

Waterloo, ON, N2L 3G1, Canada 15

School of Transportation and Logistics, Southwest Jiaotong University, Chengdu, P. R. China 16

Phone: (519) 888-4567 ext 33984, Email: [email protected] 17

18

Avalon J. Olesen 19

Field Research Assistant 20

Department of Civil & Environmental Engineering, University of Waterloo 21

Waterloo, ON, N2L 3G1 22

Email: [email protected] 23

24

25

26

27

Paper accepted for presentation at the 93rd Annual Meeting of the Transportation Research 28

Board 29 January 2014 30

Word count = 4300 (text) + 12*250 (figures and tables) ~ 7300 31

32

33

34

TRB 2014 Annual Meeting Paper revised from original submittal.

H o s s a i n , F u , O l e s e n 2

ABSTRACT 35

This paper describes an empirical study aimed at investigating the performance of the 36

anti-icing strategy for snow and ice control of parking lots and sidewalks. The research is 37

motivated by the need to address several key questions concerning various operational decisions 38

related to the anti-icing strategy, including its relative effectiveness under different weather and 39

site conditions, treatment options, and optimal application rates. Extensive field tests were 40

conducted under a wide variety of weather events using regular solid road salt, brine, and two 41

other liquid alternatives. Data collected from these tests was used to analyze the performance of 42

anti-icing operations such as friction level, bare pavement regain time, and the effects of various 43

external factors such as pavement temperature and application rate. The research has concluded 44

with findings that are directly applicable in real world winter maintenance practices. 45



1. INTRODUCTION 46

The cost of winter road maintenance is substantial in Canada. Over $1 billion is spent 47

annually for winter operations (TAC, 2003). This large cost includes the use of large amounts of 48

road salts for de-icing and anti-icing operations to remove snow and ice from transportation 49

facilities. However, salt is detrimental to the environment and has corrosive effects to the 50

infrastructure and vehicles damages (Mussato et al., 2004, NCHRP-577, 2007; Shi et al., 2009; 51

Jain et al., 2012). To reduce maintenance costs and the adverse effects of salts, a significant 52

amount of efforts have been made to improve the efficiency and effectiveness of winter 53

maintenance methods. One of the effective strategies is anti-icing, which involves applying salt 54

or other freezing point depressants prior to a snow event in order to prevent the formation of 55

snow or ice bond with the pavement surface (Ketcham et al., 1996; NCHRP-526, 2004). 56

Anti-icing has been recognized to have several significant benefits. First, it helps prevent 57

the snow from bonding with the pavement, thus achieving a higher level of friction over a snow 58

event. Second, for the same reason, anti-icing can substantially minimize the plowing efforts, 59

resulting in clearer pavement or minimal leftover snow. Third, in the case of a light snow event, 60

the pre-applied salt can melt all the snow, providing the level of service expected over a shorter 61

period. Lastly, anti-icing treatments can be made over a wider time window, enabling contractors 62

to be able to better manage their resources. 63

However, these benefits have mostly been shown or discussed in the context of roadway 64

maintenance with very few studies focusing on the effectiveness of this strategy and determine 65

its best practice when it is applied for snow and ice control of parking lots and sidewalks. The 66

operating conditions of parking lots and sidewalks are significantly different from roadways, 67

which means materials and rates that are ideal for roadway anti-icing treatments may not be 68

suitable for parking lots and sidewalks. For example, only liquid salt is effective for roadway 69

maintenance as solid would be easily dispersed by vehicular traffic; however, the vehicular 70

traffic within parking lots is substantially lower than on roadways. 71

The objective of this research is to address several critical questions related to anti-icing 72

operations for transportation facilities mainly concerned with pedestrian traffic such as parking 73

lots, sidewalks, and platforms. In particular, the research is to answer the questions as follows: 74

a) how effective is anti-icing treatment in preventing the bonding of snow and ice to pavement? 75



b) what is the relative effectiveness of anti-icing operation as compared to de-icing? c) what is 76

the optimal anti-icing application rate for specific weather and site conditions? and, d) what is 77

the comparative performance of different anti-icing materials? 78

This paper provides a detailed discussion of the results of a series of field tests conducted 79

to determine the conditions under which the anti-icing method can be more effective for a wide 80

range of pavement and environmental conditions in parking lots. The results of this study 81

provide a solid foundation for determining the optimum anti-icing methods, materials and 82

application rates for snow and ice control of parking lots and sidewalks under various winter 83

conditions. 84

85

2. LITERATURE REVIEW 86

Numerous past studies have attempted to determine the effectiveness of anti-icing on 87

road systems. Related guidelines and manuals have also been developed for highway anti-icing 88

treatments (Ketcham et al., 1996; NCHRP-526, 2004; Minnesota DOT-TRS-0902, 2009). 89

Blackburn et al. (1994) conducted a two year study to investigate the effectiveness of anti-icing. 90

They found that anti-icing can be effective at a temperature above -9°C with solid salt 91

application rate of 100lb/lane-mile (1.57 lbs/1000sqft), using saturate brine for pre-wet at a rate 92

of 0.021 to 0.025 Liter/kg (5 to 6gallons/ton). They also found that anti-icing is not effective 93

during prolonged snow fall or freezing rain. The study found that, compared to brine, magnesium 94

chloride was more successful for preventing bonding at a temperature of -5°C. Also, based on a 95

few case studies, they found that an anti-icing operation saves costs for both maintenance 96

organizations and road-users. For maintenance organizations, the cost saving is lower application 97

rates, and for road-user, the cost saving is fewer accidents due to the improvement in the 98

pavement condition. Several other studies also reported the end benefits of anti-icing as 99

compared to the conventional method of de-icing (Amsler D., 2006; O’Keefe and Shi, 2005). 100

Based on a series of workshops with the maintenance personnel, Amsler D. (2006) 101

reported that anti-icing operations can be effective with solid salts if they are properly applied 102

and can stay on the pavement after application. However, for the road sectors, solid salt with 103

water or another liquid chemical is recommended in order to minimize the bounce and scatter 104

tendencies of salts from the wind-blow caused by vehicular traffic. The NCHRP-526 report 105



(2004) also states that dry solid salt can be effective under pre-application (anti-icing) when 106

applied at traffic speed under 45km/h, and traffic volume under 100 vehicles per hour. The report 107

also indicates that parking areas present a unique potential for anti-icing operations with solid 108

salt for the reason of less expected dispersion effects. 109

Regarding anti-icing materials, past studies have evaluated the relative performance of 110

regular dry salt, pre-wet salt and regular brine. Fonnesbech J. (2007) conducted a study to 111

evaluate anti-icing performance of pre-wetted salt and brine. They compared pre-wetted salt (salt 112

and brine ratio of 70:30 by weight) at application rate 10gm/m2 (2.05lbs/1000sqft) to 20 % brine 113

applied at 20ml/m2(6.10L/1000sqft or 80gallons/lane-mile). The study showed anti-icing with 114

brine is more effective than pre-wetted salt due to the more evenly distribution and longer 115

retention of brine. Fu et al. (2012) conducted another study for the effectiveness of anti-icing 116

using different liquids and pre-wetted solid salt. The study evaluated the performance of regular 117

brine compared to a mixture of beet juice and brine (30:70 mixture). The effectiveness was 118

measured comparing the friction data from the test sections treated by the above mentioned anti-119

icing materials. They employed both materials as pre-wetting liquids, and direct applications. 120

Their study revealed that both brine and the mixture performed similarly by achieving the same 121

range of coefficients of friction when they were used as a pre-wetting chemicals, while the 122

mixture outperformed brine when they were applied alone as direct application on the roadways. 123

In summary, a number of studies have been conducted in the past to evaluate the 124

effectiveness of anti-icing, and to develop guidelines for anti-icing materials and application 125

rates; however, these studies have exclusively focused on highways. The results from these 126

studies cannot be transferred to the low volume transportation facilities, such as parking lots, 127

sidewalks, and transit platforms, due to the significant differences in service requirements and 128

operating conditions. The objective of this study is to develop a quantitative understanding of the 129

effectiveness of anti-icing for specific weather conditions, thus providing guidelines for selecting 130

the right anti-icing methods, materials, and application rates for snow and ice control in parking 131

lots and sidewalks. 132

133

134



3. DESCRIPTION OF FIELD TEST 135

In order to investigate the effectiveness of ant-icing, a series of field tests were conducted 136

during the winter season of 2012-2013. The tests were conducted under a wide range of weather 137

conditions covering 50 events (Figure 1). The following section details the test site, testing 138

method and results. 139

140

141

Figure 1: Winter Events 2012-2013 142

143

3.1 Test Site 144

The test site location was Parking Lot C, which is at the south-east end of the University 145

of Waterloo’s South Campus (Figure 2). The parking lot is made of asphalt concrete and is in 146

good condition, with a slight sloping throughout. There are 900 parking stalls and 8 driveways. 147

The tests took place in multiple locations within the parking lot. These locations were recorded 148

on a map to avoid repetition and contamination of the data. 149

150

-15

-10

-5

0

5

10

15

20

25

Days

Total Snow Depth (cm) Avg Pave. Temp (°C) Avg Air Temp (°C)



151

Figure 2: Test Site: University of Waterloo, City of Waterloo, Ontario, Canada 152

153

3.2 Test Method 154

Anti-icing treatments were performed 2 to 12 hours in advance of snow events while de-155

icing operations were done at the end of the snow events. Solid road salt was tested over all the 156

anti-icing events under both plowed and unplowed conditions while liquid salts were only tested 157

for the relatively long storms and under plowed pavement conditions. 158

The test sections were cordoned off to prevent traffic contamination of the tests. Hence, 159

the results from these tests can be directly applicable for foot traffic ways (platforms, side-walks) 160

and parking lots with low volume vehicular traffic. The results can also be equally used for the 161

worst possible case scenarios for any parking lots. Note that separate tests have been conducted 162

on driveways to account for traffic effects and the results will be reported in a separate 163

publication. 164

The solid material used in this study was solid regular road salt. The liquid salts used 165

were regular Brine, Caliber M1000, and Snow Melter 2. Table 1 shows the chemical 166

compositions of each type of material used in the tests. 167

168

169

170

171

172



Table 1: Materials Used in the Tests 173

Salt Name Constituents Composition Percentage

Regular Road Salt NaCl 100%

Brine NaCl

Water

23.3%

76.7%

Caliber M1000 Magnesium Chloride

Carbohydrate

Water

27%

6%

67%

Snow Melter 2 Glycerine

Polyether Polymer

Sodium Lactate

Sorbitol

Sodium Formate

Sodium Acetate

1, 2- Butanediol

Water

15%-20%

10%-20%

4%-10%

2%-4%

1%-4%

1%-4%

1%-2%

Balance

174

There are many similarities of how the anti-icing and de-icing experiments were 175

conducted. The salt types and application process were identical. The solid salts were measured 176

out using an electronic scale and were applied manually, and the liquid salts were applied with 177

the liquid sprayer called SnowEx SL-80. 178

The solid salt application rates varied from 5 to 50lbs/1000sqft, where 5 to 179

25lbs/1000sqft were commonly used, and liquid salts tested at rates of 3 to 10L/1000sqft. First, 180

trials were set on recommendations from manufacturers and then adjusted considering snow 181

conditions, pavement temperatures, and other variables as tests proceeded over the period. For 182

each liquid tested, the ejecting rate from the spray nozzle was calibrated first. Then the spraying 183

times for tested sections (a typical parking stall 8ft x20ft) for various application rates for each 184

liquid were calculated (this is due to the difference in their viscosity). The spraying times for 185

Brine, Caliber M1000, and Snow Melter 2 have been tabulated in Table 2 as an example. Several 186

iterations and calibrations of the spraying times were conducted, ensuring a uniform spray of 187

each material on the test sections. 188



Table 2: Liquids Spraying Rates and Times 189

Material

3L/1000sqft

(40 gallons/lane-

mile)

5L/1000sqft

(65 gallons/lane-mile)

7L/1000sqft

(90gallons/lane-mile)

10L/1000sqft

(130 gallons/lane-mile)

Brine 23s 39s 54s 78s

Caliber M1000 21s 35s 50s 70s

Snow Melter 2 37s 62s 86s 124s

190

When applying the liquid salt, the desired amount of solution was poured into the 191

sprayer. A timer was set while someone walked uniformly back and forth inside the parking stall. 192

Spraying was continuous until the desired rate was achieved. After each material was used, the 193

container was emptied and cleaned before the next chemical was applied. A flow chart showing 194

the two test procedures is given in Figure 3. 195

196

a) Anti-icing Test b) De-icing Test 197

Figure 3: Anti-icing and De-icing Process 198



3.3 Data Collection 199

At the start of the test, a master event and maintenance form was first filled out, including 200

the start and end of the event. Then, a data form was filled out at a uniform interval (usually on 201

an hourly basis), recording: 202

Weather data from Environment Canada website (Region of Waterloo station) 203

Time 204

Pavement surface and snow top temperature (by IR surface temperature reader) 205

Percent bare pavement 206

Friction levels (qualitative, quantitative by T2GO Friction Tester) 207

Snow-pavement bonding state 208

Residual salts level (qualitative, quantitative by SOBO20 Salinity Meter) 209

Contaminate type (snow, slush, wet pavement, ice) 210

Note that, for each test date, data collection continued until the desired level of service was 211

achieved. A bare pavement of 80%-100% was considered as level of service, LOS_A. 212

213

4. DATA ANALYSIS AND RESULTS 214

This section examines all the data collected and compares different anti-icing methods, 215

materials, and application rates. Note that, there were a total of approximately 100 anti-icing 216

tests conducted with solid road salt, on average 20 tests were performed with three liquid salts. 217

Two key performance measures are used, namely, bare pavement regain time (BPRT) and 218

friction level. Bare pavement regain time (BPRT) is defined as the elapsed time from the end of 219

a snow event to the time when the pavement reaches at least 80% bare. The friction level of a 220

pavement is represented by the coefficient of friction and a descriptive measure of slipperiness. 221

The former is collected using the T2GO friction tester described previously while the latter is 222

checked manually by the observer. This section summarizes the results according to the three 223

questions raised in introduction. 224

225

4.1 Effectiveness of Anti-icing for Preventing Snow and Ice Bonding 226

As discussed previously, anti-icing treatments are motivated by their potential in 227

preventing the bonding of snow and ice to a pavement surface by lowering the freezing point of 228



water through the use of salt. To evaluate the effectiveness of anti-icing operations in achieving 229

this potential, the states of bonding and friction levels at the treated sections (i.e., anti-icing was 230

done) are compared to those of the control sections (do-nothing sections). For both cases, the 231

accumulated snow was first removed by the plow truck or using a shovel before observations and 232

friction were taken. 233

Figure 4(a) shows the measurements of the coefficient of friction for sections treated with 234

anti-icing as compared to those without anti-icing operations. As expected, anti-icing operations 235

were highly effective in preventing the bonding of snow and ice. Except two cases, the 236

improvement in friction level was over 50%. For the two events that anti-icing was not effective, 237

the main reasons were the relatively low temperature and high amount of precipitation of the 238

events, and long event duration. For instance, the event which occurred on January 22, 2013 had 239

an average pavement temperature -11.5°C, which is below the effective temperature range of 240

regular salt. Three additional tests were also conducted using liquid as an anti-icing agent. 241

Figure 4(b) shows the friction of coefficients observed across the two scenarios: do-nothing and 242

anti-icing using brine. Again, the effect of preventing pavement bonding was clearly shown for 243

both solid and liquid. This quantitative evidence was further confirmed by the visual observation 244

of slipperiness levels between treated sections and untreated sections. 245

246

a) Anti-icing Using Solid Road Salt 247

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Coef

fici

ent

of

Fri

ctio

n

Date

With Anti-icing Without Anti-icing (Do-nothing Sections)



248

249

b) Anti-icing Using Brine 250

Figure 4: Effectiveness of Anti-icing Using Solid Road Salt and Brine 251

4.2 Comparative Performance of Anti-icing and De-icing Treatments 252

While the main motive of the anti-icing strategy (e.g., applying salt in advance) is to 253

prevent snow and ice from bonding to the pavement surface so that they can be removed easily 254

by plowing operations, it could also be implemented as pre-application of salt for the purpose of 255

melting snow and ice, similar to the conventional de-icing strategy (applying salt after the start, 256

mostly at the end, of an event). Intuitively, if little dispersion and dilution occur after salt is 257

applied, pre-application and after-application of the same amount of salt should perform 258

similarly in terms of snow melting capacity (total amount of snow and ice that can be melted). 259

However, the former should be expected to achieve better performance in terms of bare 260

pavement regain time because it does not need to break the newly formed bonds. If this is true, it 261

would mean that it is always preferable to apply salt in advance of an event (i.e., anti-icing) than 262

after the event for the snow storms when less dilution is expected for some form of precipitation 263

(e.g., freezing rain, wet snow). Furthermore, applying salt in advance has the advantage of an 264

easier workload management as it has a wider time window for operations. To avoid any 265

0

0.1

0.2

0.3

0.4

0.5

0.6

Feb. 18, 2013 Feb. 27, 2013 Mar. 6, 2013

Do Nothing Brine



confusion in terminologies, the following discussion still uses anti-icing and de-icing for pre-266

application and after-application, respectively. 267

Tests were conducted for a comparative analysis of these two types of operations, which 268

included applying the same amount of salt before and after an event, at different sections, with 269

multiple application rates. Figure 5 shows how the coefficient of friction changed over time for 270

anti-icing and de-icing sections treated with regular salt with application rate 5lbs/1000sqft for 271

two similar events. Note that snow was not plowed in both cases. It can be observed that, in both 272

cases, anti-icing performed significantly better than de-icing operations in terms of the overall 273

friction level over the events and bare pavement regaining period. 274

275

Figure 5: Comparison of Performance between Anti-icing and De-icing Operations 276

(Legend shows test date, treatment type, application rate in lbs/1000sqft, pavement temperature, 277

snow amount and snow type) 278

279

The differences between anti-icing and de-icing operations are also compared using the 280

performance measure of bare pavement regain time (BPRT). Two scenarios are considered, 281

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Before Event After Event 3 Hrs After 6 Hrs After

Coef

fici

ent of

Fri

ctio

n

Jan 16-17 2013, Anti-

icing, Rate 5, -3.5°C,

1.5cm, Very Loose

Jan 16-17 2013,

Deicing, Rate 5, -

3.5°C, 1.5 cm, Very

Loose

Feb 22- 23 2013,

Deicing, Rate 5, -

4.7°C, 1.3cm, Loose

Feb 22-23 2013, Anti-

icing, Rate 5, -4.7°C,

1.5cm, Loose



namely, unplowed and plowed. For the unplowed conditions, the tests included nine snow events 282

with snowfall ranging from 0.3cm to 7.8cm and temperatures from ~0°C to ~-4°C. Salts were applied 283

before the event for anti-icing sections. For de-icing operations, salts were applied after precipitation 284

stopped using the same rates as the anti-icing sections. 285

Figure 6 shows the relationship between average level of service (LOS) improvement, as 286

represented as the reduction of BPRT, between anti-icing and de-icing operations, and salt 287

application rate. Several observations can be made from the test results. Firstly, anti-icing 288

operations outperformed de-icing in almost all cases with average BPRT being from ~0.5 to 3.5 289

hours shorter. Secondly, the advantage of anti-icing operations appeared to be higher in light 290

events as compared to heavier events. Thirdly, an interesting and important observation is the 291

trend between the salt application rates and the bare pavement regain time. It shows that the 292

snow melting performance of salts is marginally sensitive to the application rate in general. It 293

can also be seen that anti-icing was less effective when event duration was relatively longer, or the snow 294

was wet. This result makes intuitive sense, as the salt applied in advance could be lost due to the high 295

dilution, which is also supported by literature (Blackburn et al. 1994; Ketcham et al.1996; Fu et al. 2013). 296

297

298

Figure 6: Benefit of Pre-application (Anti-icing) - LOS Improvements (BPRT Reduction) 299

as Compared to After-application (De-icing) 300 301

302

0

0.5

1

1.5

2

2.5

3

3.5

4

5 10 15 20 25

LO

S I

mpro

vem

ent

(hrs

)

Salting Rates (lbs/1000sqft)

Dec 29 2012, -1.45°C, 2cm, Packed Feb 22 2013, , -3.32°C, 1.3cm, Loose

Jan 16 2013, -3°C, 2.25cm, Very Loose Jan 19 2013, -0.7°C, 0.5cm, Packed

Feb 19 2013,-2.3, 3.5cm, Packed Mar 6 2013, -0.7°C, 7.8cm, Wet



4.3 Optimal Anti-icing Application Rates Using Solid Road Salt 303

When anti-icing is implemented for the sole purpose of preventing bonding of snow to 304

pavement, the amount of salt being used may not need to be large. To find out the minimum 305

application rates for achieving this anti-icing objective, a series of tests were conducted using 306

different anti-icing application rates. Figure 7 shows the coefficient of friction of a pavement 307

surface as a function of the anti-icing application rate for the plowed anti-icing sections. An 308

application rate of zero means that the section was not treated with anti-icing. As it can be 309

observed, an application rate as low as 5 lbs/1000sqft could achieve the main purpose of 310

preventing the bonding and improving the friction level. This is also true with respect to bare 311

pavement regain time, as shown in Figure 8. 312

It can be clearly seen that only a small amount of salt (5lbs/1000sqft or less) was needed to 313

achieve bare pavement immediately after plowing. 314

315

316

317 Figure 7: Friction Performance of Anti-icing Treatments 318

(Notes: Friction measurements were taken after plowing. Legend shows different test days with 319 pavement temperature, snow amount and snow type) 320

321 322 323 324

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0 5 10 15 20 25 30

Coef

fici

ent

of

Fri

ctio

n

Salt Application Rate (lbs/1000sqft)

-1.7, 2cm, Packed

-2.3, 3.5cm, Packed

-3.32, 1.3cm, Loose

-5.6, 1.3cm, Very wet



325 326

Figure 8: BPRT Performance of Anti-icing Treatments 327 (Notes: Bare pavements regain time from plowing. Legend shows different test days with 328

pavement temperature, snow amount and snow type) 329

330

4.4 Comparison of Different Materials for Anti-Icing 331

Tests were also conducted to investigate the differences in anti-icing performance between 332

three liquid products, including regular brine, Caliber M1000, and Snow Melter 2. As shown in 333

Figure 9, all sections treated with liquid anti-icing had higher friction levels than those which 334

were not treated. The differences between the three liquids were relatively small, which were 335

also true in terms of bare pavement regain time (BPRT), as shown in Figure 10. It can be 336

observed that the three liquids had similar performances under all application rates, similar to the 337

results for rock salt. The anti-icing treatment sections generally reached 100% bare pavement at 338

similar times, regardless of application rates. This suggests a low application rate 339

(e.g. 3 L/1000sqft) is needed to reach the desired level of service immediately after plowing. 340

Note that, snow started again, after the plowing operation, during the tests conducted on 341

February 27, 2013, resulting in relatively longer bare pavement regain time. 342

In addition to the testing results shown in Figure 10, the three liquids were also tested for 343

a big event amounting in 21cm snow, which was plowed at the end of the event. Three pavement 344

0

1

2

3

4

5

6

7

8

9

0 5 10 15 20 25 30

BP

RT

(h

rs)

Salt Application Rates (lbs/1000sqft)

-1.7, 2cm, Packed

-2.3, 3.5cm, Packed

-3.32, 1.3cm, Loose

-5.6, 1.3cm, Very wet



conditions were clearly noticed. First, the snow was bonded to the pavement, degrading the 345

performance of the plowing operation. Second, the pavement condition remained the same across 346

the test sections, regardless of salt type and application rate. Third, the sections treated with 347

Snow Melter 2 had marginally higher coefficient of friction than other sections, but the 348

differences were relatively small. 349

350

351

Figure 9: Coefficient of Friction for Do-nothing Sections and Liquid Salts Applications 352

(Note: Snow Melter2 was not tested on Mar. 6, 2013) 353

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

2013-02-18 2013-02-27 2013-03-06

Co

effi

cien

t of

Fri

ctio

n

Do-nothing Sections Regular Brine CaliberM1000 Snow Melter2



354

Figure 10: Anti-icing Events Comparing Liquid Salts Performances 355

(Notes: Legend shows test days with different chemical, pavement temperature, snow amount 356

and snow type) 357

358

5. CONCLUSIONS 359

360

This paper has presented the results from a series of field tests aiming at determining the 361

performance of anti-icing treatments for snow and ice control of parking lots and sidewalks. The 362

research is mainly concerned with the issues of the effectiveness and relative performance of 363

anti-icing operations using different materials and application rates under different weather 364

events. The main findings from this study include: 365

366

Anti-icing was found highly effective in preventing the bonding of snow, improving 367

friction levels, and improving bare pavement regain times; 368

Anti-icing operations, when used as pre-application, were found to perform much 369

better than after-application (de-icing) for light snow events; 370

0

1

2

3

4

5

6

0 1 2 3 4 5 6 7 8 9 10 11

BP

RT

aft

er P

low

(h

rs)

Application Rate (L/1000sqft)

Feb 19, 2013, Brine, -

0.3°C, 3.5cm, Wet

Feb 19, 2013, Snow

Melter2, -0.3°C, 3.5cm,

WetFeb 19, 2013, Caliber

M1000, -0.3°C, 3.5cm,

WetFeb 27, 2013, Brine, -

3.32°C, 1.3 cm, Packed

Feb 27, 2013, Caliber

M1000, -3.32°C, 1.3 cm,

PackedFeb 27, 2013, Snow

Melter2, -3.32°C, 1.3 cm,

PackedMar 6, 2013, Caliber

M1000, -1.67°C, 7.8cm,

Very Loose



Compared to solid salt, brine was found to be more effective under the condition that 371

the same amount of salt (NaCl) was used; 372

The two other alternative liquid products were found to perform similar to regular 373

brine for anti-icing treatments; 374

The performance of anti-icing operations also depends on the nature of the snow 375

event. For long and intense events, anti-icing operations were found to be ineffective 376

in preventing the snow bonding with the pavement. 377

378

It should be noted that additional field tests will be conducted in the coming winter 379

season to address some of the limitations and remaining issues of this research. More tests will 380

be conducted using alternative liquid products for both anti-icing and de-icing purposes. In 381

particular, there is a significant interest in applying non-chloride de-icers for minimizing the 382

environmental and corrosive effects of chloride salts used for maintenance operations. Future 383

research will also attempt to quantify the effects of other various factors, such as dilution 384

potential, traffic, and pavement type on the performance of anti-icing operations. 385

386

387

ACKNOWLEDGEMENTS 388

389

The authors wish to acknowledge nine other research assistants who helped during field data 390

collection. A complete list of the research assistants is available in our project website: 391

www.sicops.ca. This research was supported through a Collaborative Research Development 392

(CRD) project funded by NSERC (National Science and Engineering Research Council) and 393

Landscape Ontario. A number of other organizations supported this research, as acknowledged 394

on our project website. 395

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