ArticlePDF Available

Effect of aircraft deicer on deicer-scaling resistance and frost resistance of airport pavement concrete

Authors:

Abstract and Figures

This paper studies the effect of aircraft deicer on deicer-scaling resistance and frost resistance of airport pavement concrete. The mass loss and surface profile of non-air-entrained and air-entrained concrete eroded by water and aircraft deicer are analysed. The surface profile, mass loss rate and relative dynamic elasticity modulus of air-entrained concrete eroded by water and 5% aircraft deicer are discussed during freeze-thaw cycles. It is shown that the low and medium concentration deicer has a negative effect on the deicer-scaling resistance of concrete, and 5% aircraft deicer has the greatest influence. Adding air-entraining agent can improve the deicer-scaling resistance of concrete. Compared with water, 5% aircraft deicer has a negative effect on the frost resistance of air-entrained concrete. The deicer-scaling resistance and frost resistance of air-entrained concrete meet requirements for airport pavement in the most severely cold regions in China.
Content may be subject to copyright.
Journal of Physics: Conference Series
PAPER • OPEN ACCESS
Effect of aircraft deicer on deicer-scaling resistance and frost resistance
of airport pavement concrete
To cite this article: Y Lai et al 2020 J. Phys.: Conf. Ser. 1605 012178
View the article online for updates and enhancements.
This content was downloaded from IP address 45.40.125.242 on 19/08/2020 at 15:19
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution
of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Published under licence by IOP Publishing Ltd
IoTAIMA 2020
Journal of Physics: Conference Series 1605 (2020) 012178
IOP Publishing
doi:10.1088/1742-6596/1605/1/012178
1
Effect of aircraft deicer on deicer-scaling resistance and frost
resistance of airport pavement concrete
Y Lai1, 2, 4, Y Liu1, 2, P Wang2, D X Ma2, B Guo3, K Sun3 and S Hou2
1 China Airport Construction Group Co., Ltd, Beijing, 100101, China
2 Beijing Super-Creative Technology Co., Ltd, Beijing, 100621, China
3 Beijing Daxing International Airport, Beijing, 102602, China
4cacclaiyong@126.com
Abstract. This paper studies the effect of aircraft deicer on deicer-scaling resistance and frost
resistance of airport pavement concrete. The mass loss and surface profile of non-air-entrained
and air-entrained concrete eroded by water and aircraft deicer are analysed. The surface profile,
mass loss rate and relative dynamic elasticity modulus of air-entrained concrete eroded by water
and 5% aircraft deicer are discussed during freeze-thaw cycles. It is shown that the low and
medium concentration deicer has a negative effect on the deicer-scaling resistance of concrete,
and 5% aircraft deicer has the greatest influence. Adding air-entraining agent can improve the
deicer-scaling resistance of concrete. Compared with water, 5% aircraft deicer has a negative
effect on the frost resistance of air-entrained concrete. The deicer-scaling resistance and frost
resistance of air-entrained concrete meet requirements for airport pavement in the most severely
cold regions in China.
1. Introduction
According to the safety operation requirements of civil aviation in China, the ice and snow on the aircraft
must be removed in order to ensure the safety before aircraft taking off and landing in winter. At present,
aircraft deicer is often used to remove ice and snow on aircraft. Finally, the diluted aircraft deicer flows
to the airport cement concrete pavement. It causes serious frost damage and deicer-scaling damage to
concrete, which affect the durability of concrete in cold regions [1]. In the past few decades, many
researches have been conducted to solve these problems. These researches mainly focus on the influence
of air-entraining agent [4], coarse aggregate [5, 6], binder [7], fiber [8] and nanosilica [9] on the frost
resistance and salt frost resistance of concrete. There are few studies on the influence of aircraft deicer
on deicer-scaling resistance and frost resistance of airport pavement concrete, and the raw materials and
mix proportion of these studies are not consistent with the actual application of civil airports in China.
Therefore, it is necessary to study the effect of deicer on deicer-scaling resistance and frost resistance
of concrete
2. Experiment
2.1. Raw materials
The cement is Ordinary Portland Cement 42.5. The fine aggregate is river sand with a fineness modulus
of 2.88. The sand ratio is 0.32. The coarse aggregate is limestone gravel with two grades of gravel
particle sizes. The sizes of coarse aggregate are 4.75–16 mm and 16–31.5 mm. The mixed water is tap
water. The ratio of water to cement is 0.40. The air-entraining agent is sodium dodecyl benzene sulfonate.
IoTAIMA 2020
Journal of Physics: Conference Series 1605 (2020) 012178
IOP Publishing
doi:10.1088/1742-6596/1605/1/012178
2
The freeze-thaw solution is water and aircraft deicer, which contact with concrete as corrosive solution.
The chemical components of aircraft deicer are composed of 85% industrial first-class glycol, 14%
deionized water and 1% mixture assistant.
2.2. Mix proportions
The 28-day flexural strength of airport pavement concrete must be more than 5 MPa. We used two
different mix proportions in the test. The mix proportions of concrete are given in Table 1. Non-air-
entrained concrete consisted of cement, fine aggregate, coarse aggregate, water and water reducer. Air-
entrained concrete consisted of cement, fine aggregate, coarse aggregate, water, water reducer and air-
entraining agent, and the ratio of air-entraining agent to water reducer is 0.08%.
Ta bl e 1 . Mix proportions of concrete.
Type of concrete Cement
(kg m-3)
Fine
aggregate
(kg m-3)
Coarse aggregate
(kg m-3) Water
(kg m-3)
Water
reducer
(kg m-3)
Air
-entraining
agent
(g m-3)
4.75-16
mm
16-31.5
mm
Non-air-entrained 330 652.2 554.3 831.5 132 6.6 /
Air-entrained 330 652.2 554.3 831.5 132 6.6 5.28
2.3. Specimen preparation and test method
In the paper, we prepared specimens based on the Chinese standard “Standard for test methods of long-
term performance and durability of ordinary concrete” (GB/T 50082-2009) and “Specifications for
construction of aerodrome cement concrete pavement” (MH 5006-2015). The specimens for frost
resistance were prepared in the mold of 10 cm×10 cm×40 cm. The specimens for deicer-scaling
resistance were prepared in the mold of 15 cm×15 cm×10 cm, and the size of the forming surface was
15 cm×15 cm. The specimens were cured for 1 day at 20±2 and 60% relative humidity, and then
removed from the mold. The specimens were cured for 23 days at 20±2 and above 95% relative
humidity in the air. Finally, the concrete specimens were placed in the water for curing for 4 days. At
the age of 28 days, the specimens for frost resistance were tested according to GB/T 50082-2009; the
specimens for deicer-scaling resistance were tested according to MH 5006-2015. The 2%, 3%, 4%, 5%,
6%, 12%, 25%, 50% aircraft deicer and water were selected as the freeze-thaw solution and the forming
surface of specimen was contacted with the solution. The salt freeze-thaw cycle apparatus was used, and
the temperature range was set from -20 to 20 for every 12 hours. The mass loss is the accumulated
scaling mass divided by the area of specimen that contact with the aircraft deicer or water, which is
selected as the evaluation index to indicate the deicer-scaling resistance of concrete.
3. Results and discussion
In the test, the air content of non-air-entrained concrete is 1.6%. The air content of concrete increases
because of the addition of air-entraining agent. The air content of air-entrained concrete is 3.0%. The
slump of both non-air-entrained and air-entrained concrete is 1 cm. The deicer-scaling resistance and
frost resistance of concrete are analysed.
3.1 Deicer-scaling resistance of concrete
Table 2 shows the freeze-thaw cycle test results of non-air-entrained concrete. Figure 1 shows the effect
of aircraft deicer concentration on mass loss of non-air-entrained concrete after different freeze-thaw
cycles. It can be clearly seen that the mass loss of non-air-entrained concrete increases when the aircraft
deicer concentration is less than 5% at the same freeze-thaw cycles, and then quickly decreases after
that. The mass loss of non-air-entrained concrete at 30 freeze-thaw cycles in the presence of 5% aircraft
deicer is 0.676 kg/m2, which is higher than the standard limit of 0.6 kg/m2 and 16.5 times the mass loss
IoTAIMA 2020
Journal of Physics: Conference Series 1605 (2020) 012178
IOP Publishing
doi:10.1088/1742-6596/1605/1/012178
3
of non-air-entrained concrete under water exposure. Figure 2 shows the effect of freeze-thaw cycles on
mass loss of non-air-entrained concrete. It can be noticed that the mass loss of non-air-entrained concrete
tend to increase linearly with freeze-thaw cycles. Compared with water freezing and thawing, the mass
loss is greater when the non-air-entrained concrete is immersed in 2%~12% aircraft deicer, the mass
loss is smaller when the non-air-entrained concrete is immersed in aircraft deicer that its concentration
is more than 25%. For 2% and 3% aircraft deicer, the mass loss of non-air-entrained concrete is basically
the same.
Ta bl e 2 . Mass loss of non-air-entrained concrete.
Aircraft deicer
concentration
Mass loss (kg m-2)
5 cycles 10 cycles 15 cycles 20 cycles 25 cycles 30 cycles
0 0.005 0.010 0.017 0.023 0.033 0.041
2 0.021 0.069 0.145 0.207 0.263 0.298
3 0.031 0.076 0.148 0.209 0.265 0.309
4 0.052 0.154 0.265 0.362 0.448 0.516
5 0.071 0.222 0.380 0.494 0.595 0.676
6 0.014 0.031 0.060 0.088 0.127 0.162
12 0.013 0.025 0.041 0.052 0.066 0.078
25 0.007 0.010 0.011 0.013 0.017 0.022
50 0.004 0.007 0.008 0.009 0.012 0.015
Figure 3 shows the surface profile of non-air-entrained concrete under water and aircraft deicer
exposure at 30 freeze-thaw cycles. The mass loss of non-air-entrained concrete is different under water
and aircraft deicer exposure, which indicates that the different damage have taken place.
Figure 1. Effect of aircraft deicer concentration
on mass loss of non-ai
r
-entrained concrete.
Figure 2. Effect of freeze-thaw cycles on mass
loss of non-ai
r
-entrained concrete.
Figure 4 shows the surface profile of non-air-entrained concrete eroded by water after freeze-thaw
cycles. The forming surface of concrete is smooth and flat before test. Mortar is obviously peeled off
from the forming surface at 20 cycles. Figure 5 shows the surface profile of non-air-entrained concrete
eroded by 5% aircraft deicer after freeze-thaw cycles. Only at 10 cycles, a large amount of mortar is
peeled off from the forming surface. The microcracks appeared and air voids expanded, making the
aircraft deicer easier to enter the inner structure of non-air-entrained concrete. Figure 6 shows the surface
profile of air-entrained concrete eroded by 5% aircraft deicer after freeze-thaw cycles. Only the cement
paste is peeled off from the forming surface.
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 102030405
0
Mass losskg/m2)
Aircraft deicer concentration (%)
5 cycles 10 cycles
15 cycles 20 cycles
25 cycles 30 cycles
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 5 10 15 20 25 3
0
Mass losskg/m2)
Number of freeze-thaw cycles
0% 2%
3% 4%
5% 6%
12% 25%
50%
IoTAIMA 2020
Journal of Physics: Conference Series 1605 (2020) 012178
IOP Publishing
doi:10.1088/1742-6596/1605/1/012178
4
a 0%
2% c3% d 4%
e 5% f 6% g 12% h 50%
Figure 3. Surface profile under water and aircraft deicer exposure at 30 cycles.
a Before test
10 c
y
cles c20 c
y
cles d 30 c
y
cles
Figure 4. Surface profile of non-air-entrained concrete eroded by water.
a Before test
10 c
y
cles c20 c
y
cles d 30 c
y
cles
Figure 5. Surface profile of non-air-entrained concrete eroded by 5% aircraft deicer.
a Before test
10 cycles c 20 cycles d 30 cycles
Figure 6. Surface profile of air-entrained concrete eroded by 5% aircraft deicer.
IoTAIMA 2020
Journal of Physics: Conference Series 1605 (2020) 012178
IOP Publishing
doi:10.1088/1742-6596/1605/1/012178
5
Figure 7 shows the variation of mass loss with aircraft deicer concentration at 30 freeze-thaw cycles.
It can be clearly seen that the deicer-scaling resistance of concrete is significantly improved by the
addition of air-entraining agent, especially for concrete eroded by aircraft deicer with low and medium
concentration. The mass loss of air-entrained and non-air-entrained concrete eroded by 5% aircraft
deicer is the largest. The mass loss of non-air-entrained concrete is 16.9 times that of air-entrained
concrete at 30 cycles. Figure 8 shows the variation of mass loss with freeze-thaw cycles. The mass loss
of non-air-entrained concrete increases rapidly, while that of air-entrained concrete increases slowly.
Figure 7. Variation of mass loss with aircraft
deicer concentration at 30 freeze-thaw cycles.
Figure 8. Variation of mass loss with freeze-
thaw cycles.
3.2 Frost Resistance
Figure 9 and Figure 10 show the variation of mass loss rate and relative dynamic elasticity modulus with
freeze-thaw cycles. At 300 freeze-thaw cycles, the mass loss rate of air-entrained concrete eroded by
water and 5% aircraft deicer is 0.1% and 0.4%, respectively; the relative dynamic elasticity modulus of
air-entrained concrete eroded by water and 5% aircraft deicer is 66.8% and 62.7%, respectively. The
frost resistance of air-entrained concrete eroded by 5% aircraft deicer is worse than that of water.
Figure 9. Variation of mass loss rate with freeze-
thaw cycles.
Figure 10. Variation of relative dynamic elasticity
modulus with freeze-thaw cycles.
(a) Concrete eroded by wate
r
(b) Concrete eroded by 5% aircraft deice
r
Figure 11. Surface profile of air-entrained concrete at 300 freeze-thaw cycles.
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 1020304050
Mass losskg/m2)
Aircraft deicer concentration (%)
Non-air-entrained concrete
Air-entrained concrete
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 5 10 15 20 25 30
Mass losskg/m2)
Number of freeze-thaw cycles
Non-air-entrained concrete
Air-entrained concrete
-0.1
0.0
0.1
0.2
0.3
0.4
0 50 100 150 200 250 300
Mass loss rate (%)
Number of freeze-thaw cycles
Water
Aircraft deicer
60.0
70.0
80.0
90.0
100.0
0 50 100 150 200 250 300
Relative dynamic elasticity
modulus (%)
Number of freeze-thaw cycles
Water
Aircraft deicer
IoTAIMA 2020
Journal of Physics: Conference Series 1605 (2020) 012178
IOP Publishing
doi:10.1088/1742-6596/1605/1/012178
6
Figure 11 shows the surface profile of air-entrained concrete eroded by water and 5% aircraft deicer
at 300 freeze-thaw cycles. It can be clearly seen that only cement paste is peeled off from air-entrained
concrete eroded by water; while mortar is peeled off from air-entrained concrete eroded by 5% aircraft
deicer, and a crack appears on the concrete surface. They meet the frost resistance requirements for
airport pavement concrete in the most severely cold regions in China.
4. Summary
The mass loss of non-air-entrained concrete increases when the aircraft deicer concentration is less than
5% at the same freeze-thaw cycles, and decreases quickly when the aircraft deicer concentration is
5%~25%, and then tends to be stable after that. The mass loss of non-air-entrained concrete tends to
increase linearly with freeze-thaw cycles for water and aircraft deicer with different concentrations. The
mass loss of non-air-entrained and air-entrained concrete eroded by 5% aircraft deicer is the maximum,
which is 0.676 kg/m2 and 0.040 kg/m2, respectively. Compared with water freezing and thawing, the
deicer-scaling resistance of non-air-entrained concrete eroded by aircraft deicer with low and medium
concentration is reduced, while that of high concentration is slightly improved. The deicer-scaling
resistance of air-entrained concrete is significantly improved by the addition of air-entraining agent.
Compared with water freezing and thawing, the 5% aircraft deicer has a great effect on the mass loss
rate and relative dynamic elastic modulus of air-entrained concrete. Therefore, the 5% aircraft deicer
has a negative effect on the frost resistance, but air-entrained concrete can meet the frost resistance of
300 freeze-thaw cycles and the deicer-scaling resistance of 0.6 kg/m2 for airport pavement in the most
severely cold regions in China.
Acknowledgments
This work was financially supported by Science and Technology Project of CAAC (20150225) and
Security Capacity Building Project of CAAC (20180275).
References
[1] S. Jacobsen, G.W. Scherer, E.M. Schulson. Concrete-ice abrasion mechanics. Cem. Concr. Res.
73 (2015) 79-95.
[2] G. Duan, C. Fang. Research progress and new thinking of destruction of due to freeze-thaw cycles.
Concrete 05 (2013) 16-20.
[3] Q. Yang. One of mechanisms on the deicer-frost scaling of concrete (II): degree of saturation and
ice-formation pressure during freezing-thawing cycle. J. Build. Mater. 15 (2012) 742-746.
[4] J. Yuan, Y. Wu, J.K. Zhang. Characterization of air voids and frost resistance of concrete based
on industrial computerized tomographical technology. Construction and Building Materials
168 (2018) 975-983.
[5] W.Z. Li, L.C. Cai, Y. G. Wu, et al. Assessing recycled pavement concrete mechanical properties
under joint action of freezing and fatigue via RSM. Construction and Building Materials 164
(2018) 1–11. Construction and Building Materials 164 (2018) 1-11.
[6] K.H. Liu, J.C. Yan, Q. Hua, et al. Efects of parent concrete and mixing method on the resistance
to freezing and thawing of air-entrained recycled aggregate concrete. Construction and
Building Materials 106 (2016) 264-273.
[7] M. Nili, M. Zaheri. Deicer salt-scaling resistance of non-air-entrained roller-compacted concrete
pavements. Construction and Building Materials 25 (2011) 1671-1676.
[8] Q.B. Yang, B.R. Zhu. Effect of steel fiber on the deicer-scaling resistance of concrete. Cement
and Concrete Research 35 (2005) 2360-2363.
[9] M. Gonzalez, S.L. Tighe, K. Hui, et al. Evaluation of freeze/thaw and scaling response of
nanoconcrete for portland cement concrete (PCC) pavements. Construction and Building
Materials 120 (2016) 465-472.
... In recent years, many airports have experienced cracks, spalling, warping, misalignment, and even sand and stones in the process of cement concrete pavement [4,5], which mainly reflects the durability of concrete, seriously affects the normal operation of airport runways and the safety of aircraft takeoff and landing, and may even cause the failure of runway function or serious flight accidents [6,7]. In addition, the combination of a harsh climatic environment, frequent sudden natural disasters, and an unnatural environment (such as de-icing salt) accelerates the damage and service-life shortening of airport concrete pavement surfaces [8][9][10]. Concrete's carbonation, water and chloride ion penetration, sulfate corrosion, freeze-thaw Tetraethyl orthosilicate, isobutyltriethoxysilane, acrylic acid, hydrochloric acid, phosphoric acid, anhydrous ethanol, wetting agents, and distilled water were used in the experiments. ...
Article
Full-text available
In this paper, three modified tetraethyl orthosilicate surface treatment agents were prepared by using tetraethyl orthosilicate (TEOS) as the preparation monomer, isobutyltriethoxysilane (IBTS) as the hybridizer, and acrylic acid, phosphoric acid, and hydrochloric acid as the catalysts. The effects of the three modified tetraethyl orthosilicate surface treatment agents on the permeability of airport pavement surface concrete were investigated by water absorption tests, water contact angle tests, water penetration resistance tests, chloride ion penetration resistance tests, and carbonation tests, and the mechanisms of action of the modified tetraethyl orthosilicate surface treatment agents were analyzed by microscopic tests. The results showed that all three tetraethyl orthosilicate surface treatment agents could significantly improve the impermeability of concrete, among which the modified tetraethyl orthosilicate surface treatment agent with hydrochloric acid as the catalyst had the most obvious effect on the improvement of the impermeability of concrete. Acrylic acid was weaker than hydrochloric acid as the catalyst of a modified tetraethyl orthosilicate surface treatment agent for the improvement of concrete impermeability; it was only slightly stronger than hydrochloric acid as the catalyst of modified tetraethyl orthosilicate surface treatment agent in terms of the improvement of concrete’s resistance to water penetration, and the difference between the two was not significant. Phosphoric acid as a catalyst of the modified tetraethyl orthosilicate surface treatment agent was the least effective for concrete impermeability; it was only stronger than the other two modified tetraethyl orthosilicate surface treatment agents in the improvement of concrete resistance to carbonation, and the carbonation depth of the concrete was only 1 mm in 28 days. SEM and MIP tests showed that the modified tetraethyl orthosilicate surface treatment agents improved the impermeability of concrete mainly by producing additional hydrated calcium silicate gel to plug microcracks and pores, reduce the total porosity of the concrete and the number of multi-harmful and harmful pores, and improve the compactness of the concrete. The test results can provide a reference for the development of modified tetraethyl orthosilicate surface treatment agents and their application in airport pavement surface engineering.
... They believed that the change in the micro-structure of the salt freezing environment is the main factor for the decrease in the mechanical properties of concrete. Lai Y. [13] investigated the influence of runway deicing salts (the main component is CH 3 COOK) on the salt-freezing resistance of airport runway concrete. They discussed the influence of freezing-thawing cycles in the water and runway deicing salt environment on the apparent morphology, mass loss rate, and relative dynamic elastic modulus of concrete. ...
Article
Full-text available
The macroscopic mechanical properties and frost resistance durability of concrete are closely related to the changes in the internal pore structure. In this study, the two-dimensional and three-dimensional ICT (Industrial Computerized Tomography) pore characteristics of C30 concrete specimens before and after freezing and thawing in clean water, 5 wt.% NaCl, 5 wt.% CaCl2, and 5 wt.% CH3COOK solution environments are obtained through concrete frost resistance durability test and ICT scanning technology. The effects of pore structure changes on concrete frost resistance, durability, and compressive strength mechanical properties after freezing and thawing cycles in different salt solution environments are analyzed. This paper provides new means and ideas for the study of concrete pores. The results show that with the increase in the freezing and thawing times, the concrete porosity, two-dimensional pore area, three-dimensional pore volume, and pore number generally increase in any solution environment, resulting in the loss of concrete compressive strength, mortar spalling, and the decrease in the relative dynamic elastic modulus. Among them, the CH3COOK solution has the least influence on the concrete pore changes; the NaCl solution has the greatest influence on the change in the concrete internal porosity. The damage of CaCl2 solution to concrete is second only to the NaCl solution, followed by clean water. The increase in the concrete internal porosity from high to low is NaCl, CaCl2, clean water, and CH3COOK. The change in the pore volume of 0.1 to 1 mm3 after the freeze–thaw cycle is the main factor for reducing concrete strength. The test results have certain guiding value for the selection of deicing salt in engineering.
Article
Introduction. Increasing the durability of hard pavements allows you to reduce road maintenance costs by extending the intervals between repairs. Dispersed reinforcement is a well-known method of increasing the frost resistance and abrasion resistance of concrete, which has a positive effect on the durability of pavements in typical for Ukraine climatic conditions. Basalt fiber is resistant to corrosion and relatively inexpensive, which makes it promising for use in the road industry. Also, plasticizing and air-entraining admixtures must be used for concrete of hard pavement. Problem Statement. In modern economic conditions and taking into account the technological features of the preparation of mixtures, it is relevant to compare the effectiveness of the use of known methods of improving the properties of concrete for hard pavements: dispersed reinforcement and the use of air-entraining admixtures. Studying the expediency of the simultaneous use of these two methods of modifying the concrete mixture is also an important task from a scientific and practical point of view. Purpose. Determination of the influence of basalt fiber and air-entraining admixture on the strength, frost resistance and abrasion resistance of concrete of hard pavements.
Article
Full-text available
We elucidated the effects of the parent concrete and mixing approach used on the freezing/thawing resistance of air-entrained recycled aggregate concrete (ARAC). Three non-air-entrained concretes and one air-entrained concrete were used to prepare recycled coarse aggregate (RCA) samples. Three mixing approaches were also investigated. The frost resistances of the ARAC samples produced using an RCA obtained from the non-air-entrained concrete with high strength as well as the air-entrained one were close to that of conventional concrete. The mixing approach used had no effect on the frost resistance. A possible mechanism for the failure of ARAC is proposed.
Article
Full-text available
Effects of steel fibers on the deicer-scaling resistance of concrete were investigated in this paper. Results show that the deicer-scaling resistance of concrete is reduced by the addition of steel fibers at the same air content, especially for the air-entrained concrete, even though the flexural strength of concrete is significantly improved by the addition of fibers. The reason is that the average air-void spacing factor of concrete becomes larger due to the addition of steel fibers. The variations in the deicer-scaling resistance among the different concrete qualities can be fully explained by the spacing factor values.
Article
Sample pavement recycled aggregate concrete (PRAC) was prepared with waste pavement concrete from an airport in China in this study. Frost resistance and fatigue performance were analyzed by comparison against common pavement concrete. The response surface method (RSM) was used to assess the mechanical properties of PRAC under the joint action of freezing and fatigue. Design Expert and Center Composite Design (CCD) software were applied to analyze the influence rules dominating freeze-thaw cycles, fatigue iterations, and their joint action in regards to the flexural strength, compressive strength, and relative dynamic modulus of PRAC with corresponding RSM models. The three RSM relation models were fit well and effectively represent PRAC characteristics after a series of fatigue and freeze-thaw cycles. The number of fatigue iterations appears to influence flexural strength, while freeze-thaw cycles influence compressive strength; the interaction between fatigue iterations and freeze-thaw cycles substantially impacts the Pn of PRAC.
Article
The durability of PCC refers to the ability of concrete to resist weathering action, chemical attack and abrasion. Freeze/thaw and scaling are extreme conditions that occur in cold climates and with the use of deicers that can affect the durability of concrete. Nanomaterials, which have a particle size under 100 nm and a large specific surface area, are able to improve the durability of concrete. In this research nanosilica was added to concrete mix, and was found to improve the compressive strength of concrete, paste density, and reduce the external damage of samples subject to freeze/thaw cycles.
Article
Effects of NaCl concentration (by mass) on the solution absorption and degree of saturation in concrete, and the ice-formation expansion ratio and pressure of solutions were investigated under freezing-thawing cycles, and then mechanisms on the deicer-frost scaling of concrete were analyzed. Results show that the equilibrium value of ice-formation expansion ratio and pressure of solutions are significantly reduced with the increase of NaCl concentration, but the critical degree of saturation is obviously enhanced. The degree of saturation in concrete during freezing-thawing cycles in NaCl solutions are obviously higher than that in water, and the increase in degree of saturation in the concrete mainly depends on the solution absorption during the freezing, and is not related to the thawing. The ice-formation pressure in 2%-6% NaCl solution is maximum, so the deicer-frost scaling caused by NaCl solution with the low-medium concentration is most serious.
Article
This paper investigates the effects of various pozzolans on the fresh and hardened performance of non-air-entraining, roller-compacted concrete pavement. Deicer salt-scaling resistance of the specimens was evaluated for freeze–thaw cycle conditions with either a long or a short freezing period. Water–cement ratios were 0.36 and 0.43. Natural pozzolan, fly ash and silica fume were used as partial replacements for the cement, by 8%, 20%, and 20%, respectively. The results showed that the pozzolans generally improved the consistency of the mixtures compared with reference samples. Introducing silica fume improved compressive strength and, particularly, salt-scaling resistance of the specimens. Salt scaling decreased as the duration of the freeze period in the freeze–thaw cycle decreased.
Research progress and new thinking of destruction of due to freeze-thaw cycles
  • Duan
G. Duan, C. Fang. Research progress and new thinking of destruction of due to freeze-thaw cycles. Concrete 05 (2013) 16-20.