This document discusses abrasion of concrete and research into improving concrete's abrasion resistance. It defines abrasion as the wear of a material's surface due to friction or impact. Research has found lower water-to-cement ratios and replacing some concrete components (e.g. fine aggregate) with materials like fly ash or rubber can increase abrasion resistance, though results vary. Testing standards like ASTM C779 aim to simulate abrasion conditions to evaluate concrete samples. Overall, the document reviews the causes and effects of abrasion on concrete and different studies examining ways to enhance durability through material substitutions.

1. CONCRETE ABRASION
Adam Baba Abdulai
CE 702-Concrete Durability
04/28/2016

2. P a g e | 1
In the simplest of definitions, concrete is the product formed when a mixture of fine aggregates,coarse
aggregates and cement is added to water. In the modern age, concrete is the most widely used building material due
to its very favorable properties like water resistance, fire resistance, ease of formation and relatively low cost.
Depending on the use it is being intended for, the type of concrete may be chosen from a wide selection like high
performance concrete, prefabricated concrete, reinforced concrete and underwater concrete among others.The same
fundamental components are used in all concrete mixes and most of the time concrete structures perform as
expected. There are occasions however when concrete structures do fail due to accidents or structural incompetency
but the biggest culprit of concrete structure failure is durability issues.For concrete to be classified as durable, it
should be able to perform the function it was intended and designed for, it should be able to resist impacts from
changes in the natural and artificial environment which it comes into contact with and should maintain its chemical
and physicalproperties as much and for as long as possible. There are numerous challenges that might cause
concrete to deviate from being durable and this paper will concentrate on one of these: abrasion.
Abrasion is a word typically used to describe the wear of the surface of a material. In concrete, abrasion is
classified as a durability issue that negatively impacts its ability to perform its purpose as well and for as long as
needed.In his 2002 book entitled “fundamentals of durable reinforced concrete,” Mark Richardson says that
‘abrasion of concrete surfaces results from friction, which may cause a grinding action, or by repetitive impact and
overloading, which causes local crushing’[3]. The book goes on to list some possible sources of this friction as
pedestrians,vehicular traffic, materials being dragged across the surface of concrete elements or the impact of wind
borne materials [3]. Figures 1a and 1b below are illustrations of what an abraded concrete surface may look like.
The finished surfaces have been worn away, exposing aggregates and reinforcement which could cause further
issues and compromise initially expected service. On a more technical level, the American Concrete Institute came
out with ACI 201.2R, a guide to concrete durability that describes this form of concrete deterioration as a
progressive process.It says about abrasion that “initially, resistance is closely related to compressive strength at the
wearing surface, and floor wear is best judged on this basis.As the paste wears, the fine and coarse aggregates are
exposed, and abrasion and impact will cause additional degradation that is related to aggregate-to-paste bond
strength and hardness ofthe aggregate” [4]. The suggestion that compressive strength influences abrasion resistance
obviously dictates that all steps be taken to ensure that the onset of abrasion is countered with a high compressive
Figure 1a: Abradedconcretesurfaceexposing aggregates and
reinforcement [2]
Figure 1b: Abrasiondamageto concretebaffleblocks andfloorarea
in Yellowtail Diversion Damsluiceway, Montana [3]

3. P a g e | 2
strength by avoiding segregation,eliminating bleeding, proper finishing, minimizing surface w/cm, hard toweling of
the surface and proper curing procedures [4]. Due to the popularity and diverse nature of concrete use however, it is
inevitable that these causes of abrasion cannot be avoided altogetherso various experts and researchers in the
concrete field have been conducting experiments to see how best this issue can be managed if not prevented. The
American Society for Testing and Materials (ASTM) comes out with regularly employed tests for building materials
has developed a few test methods to ensure that concrete being used in construction are able to resist abrasion to at
least a reasonable extent. There are several methods provided by ASTM to determine the abrasion resistance of a
sample of concrete and the main defining factors in determining which test to use should be defined by the specific
service conditions for the project. One of these methods of testing will be discussed in detail next.
The type of testing that will be used is chosen based on how closely the service conditions are matched by
the test.This paper will concentrate on discussing ASTM C779/C779M-12 as an example method, described by
ASTM as a standard test method for abrasion resistance of horizontal concrete structures.It provides three
procedures for testing this property of concrete, firstly using revolving disks which operate by sliding and scuffing
of steel disks in conjunction with abrasive grit, then using the dressing wheel machine which operates by providing
impact and sliding friction of steel dressing wheels on the concrete and thirdly the ball bearing machine, operated by
high-contact stresses,impact, and sliding friction from steel balls [5]. All three procedures attempt to simulate real
world conditions and hence are a good look into how abrasion may affect the durability of the concrete structure in
similar conditions. The test results provide a plot of depth of wear versus time of exposure to their causative agent.
The greater the depth of wear, the less resistive the concrete sample is towards abrasion and vice versa. The
precision of these tests run in a decreasing order from the revolving disk to the dressing wheel to the ball bearing
[5].
From a literature survey,it can be seen that current research chiefly concentrates on replacing the usual
components of concrete with materials that might improve its abrasion resistance.In their 2014 paper, An Cheng
and Wei-Ting Lin studied the impact of replacing aggregate with polyolefin fibers (PF) and cement with silica fume
(SF) while varying the water to cement ratio (w/cm) on the compressive strength and ultimately abrasion resistance
of the concrete samples produced.The results of their experiments showed that the samples with lower water to
cement ratios resulted in a higher compressive strength and abrasion resistance.Samples that contained only SF as a
cement aggregate replacement and some samples that contained both SF and PF also resulted in higher compressive
strengths and abrasion resistance but samples that contained only PF as an aggregate replacement did not. On the
other hand,some samples that did incorporate both substitutes did in some cases have a detrimental effect on the
compressive strength and abrasion resistance of the concrete samples. This was due to the inability to control the
distribution of PF resulting in a lack of uniformity throughout the sample. Figures 2a and 2b below illustrates their
findings with more abrasion resistance in samples with lower w/cm ratios and the different results mentioned above.

4. P a g e | 3
A and B differentiate between the w/cm ratios while P and S represent samples with PF and SF respectively [6].
There were some good concluding results about using silica fume as a substitute forcement and whilst their results
in terms of the relationship between w/cm ratio and compressive strength and abrasion resistance was consistent
with results from other researchers, there was not a clear conclusion in terms of the effect of including polyolefin
fibers as an aggregate substitute.There was also not a clear reason why polyolefin fibers were chosen instead of
some other material. In their 2005 paper, Tsong Y. et al, published the results of replacing cement with varying
proportions of class F fly ash and varying levels of w/cm. They went off the premise that since abrasion resistance
depends mainly on the compressive strength of concrete,high-strength concrete with a superior resistance to
abrasion is used in hydraulic structures.These high-strength concrete mixtures however have properties that can
cause increased shrinkage due to high heats of hydration resulting in a higher chance of cracking and reduced
durability. Using supplementary cementitious materials like fly ash will help to reduce the adverse heat of hydration.
As seen in figure 3a and 3b below, their test results did not find any beneficial effect on the abrasion resistance of
the concrete samples with progressively increasing the amount of class F fly ash as a cement substitute [7]. Just like
An Cheng and Wei-Ting Lin [6], they found higher compressive strengths and abrasion resistance with lower w/cm
ratios and their results went further to indicate a direct relationship between this concrete property and increasing
age of the samples which was attributed to more time meaning more matured concrete. The 2005 article by Rafat
Figure 2a: Abrasion ratio ofsamples withvarying constituents and
a w/cm ratioof 0.35
Figure 2b: Abrasionratio ofsamples with varying constituents and
a w/cm ratioof0.55
Figure 3a: Effectofcement replacements bymass withclass F fly
ash on theabrasion–erosion resistanceofconcreteat28-dayage.
Figure 3b: Effect ofcementreplacements by mass with class F fly
ash on theabrasion–erosion resistanceofconcreteat91-dayage.

5. P a g e | 4
Siddique discussed the effect of including class F fly ash in concrete not as a replacement for cement but as a
substitute forfine aggregate. The researcher recognized that this use of fly ash was less common in the concrete
industry so the experiment aimed to investigate the use of fly ash as a fine aggregate replacement and note any
results on the compressive strength and abrasion resistance of different samples. As seen in figure 4a below, the
results of the experiment indicated a gradual corresponding increase in compressive strength of samples with an
increase in class F fly ash content (up to 40% replacement beyond which there were diminishing returns)and
supported the findings of Tsong Y. et al about an increase in compressive strength with an increasing age [7]. Figure
4b below shows that the results of the experiment also indicated that with increasing levels of class F fly ash used as
a fine aggregate replacement, there was an increase in abrasion resistance [8]. These findings showed that using
class F fly ash as a fine aggregate replacement had opposite and more desirable results than when using class F fly
ash as a cement replacement as Tsong Y. et al did [7]. In their 2014 article, Gesoʇlu, M., et al investigated the effect
of using different sizes of recycled waste rubber as an aggregate replacement in pervious concrete preparation. The
sizes and varieties of rubber elements used varied increasingly from fine crumb rubber to crumb rubber to tire chips.
They found that with a constant w/cm ratio and increased percentage by weight amounts of rubber instead of the
usualaggregate, there was on one hand a reduction in flexural strength and some otherconcrete properties while on
the otherhand there was a corresponding increase in abrasion resistance among other properties. Figure 5 below
shows the effect that using rubber as an aggregate replacement had on the abrasion resistivity of the concrete
samples. It can be seen that as the replacement level
increased, there was a better resistance to abrasion across all
boards.There was however a more positive effect on abrasion
resistance as the size of rubber reduced meaning the fine
crumb rubber had a better abrasion resistance than the crumb
rubber which in turn had a better abrasion resistance than tire
chips. According to their study, the rubber particles present in
the concrete projected beyond the smooth surface of the
concrete and restricting direct contact of the abrasive agent
Figure 4a: Relationship between compressivestrength
and levels of class F fly ash with time
Figure 4b: Relationshipbetweenabrasion resistance
and levelofclass F fly ash replacement
Figure 5: Relationship between abrasionandreplacement level
of aggregate withrubber

6. P a g e | 5
with the concrete surface allowing for more abrasion resistance [9]. The 2016 paper by T. Skariah and R. Gupta
which published the results of replacing fine aggregate with scrap tire rubber confirmed the findings of Gesoʇlu, M.,
et al [9]. The tests results in this experiment found that including rubber instead of natural fine aggregate also
resulted in lower compressive strengths flexural strengths and tensile strengths but higherabrasion resistance up to a
certain point. Figure 6a below shows the variation of percentage inclusion of scrap rubber and its effect on the
abrasion of the concrete sample. The higher the percentage of inclusion or rubber, the better the abrasion resistance
of the concrete sample. Figure 6b below shows the reverse effect the inclusion of rubber instead of fine aggregate
had on the compressive strength of samples. Here, the higher the percentage of scrap rubber, the lower the
compressive strength [10]. These findings are very relevant since they challenge the idea that since better abrasion
resistance is obtained with higher compressive strengths,lower abrasion resistance should be expected for lower
compressive strengths.It tells us that this generalization is not necessarily accurate and more research needs to be
done to determine where the line can be drawn between strength of a concrete sample and its abrasion resistance.
This paper has found that the abrasion of a concrete structure can be caused by a lot of factors depending
on its use.These causative agents usually cannot be avoided so it is up to the concrete to be as resilient as possible to
be able to withstand their effects as best and for as long as possible.Current research has indicated a lower w/cm
results in higher compressive strength and better abrasion resistance, and that replacing certain components (fine
aggregate, coarse aggregate and ordinary Portland cement) with other les s widely used materials could have a
favorable effect on the abrasion resistance of a concrete sample. Using fly ash as a partial replacement for fine
aggregate, using silica fume as an SCM and including scrap rubber as aggregate have all shown favorable results
and the latter case could be a strong argument for the future sustainability potential within concrete production.
There is a lot of potential research available in order to figure out the best combination of alternative materials to
produce the most abrasion resistance given a particular environmental setting.The current test methods could also
be expanded to include more service scenarios like extreme environments in order to better understand howconcrete
might act in these environments.
Figure 6a: Relationship between percent ofcrumbrubber
and depthof abrasion
Figure 6b: Relationshipbetweencompressivestrength
and percentage ofcrumb rubber

7. P a g e | 6
References:
[1] Richardson, Mark G. Fundamentals of durable reinforced concrete. CRC Press, 2003.
[2] O. Tavares. "CON 124 - Session 7 - Concrete Durability." CON 124 - Session 7 - Concrete Durability.
Alpenaccedu,30 Nov. 2013.
[3] "Erosion of Concrete in Hydraulic Structures." ACI Materials Journal MJ 84.2 (1987)
[4] ACI 201.2R – 08, “Guide to Durable Concrete,” ACI Committee 201 on Durability of Concrete, 2008.
[5] "Standard Test Method for Abrasion Resistance of Horizontal Concrete Surfaces." ASTM Compas s. ASTM, 1
Dec. 2012. Web. 19 Apr. 2016.
[6] An, Cheng, and Lin Wei-Ting. "Abrasion Resistance of Concrete Containing Polyolefin Fibers and Silica
Fumes." Polymers & Polymer Composites 22.5 (2014): 437-442.
[7] Yen, Tsong,et al. "Influence of Class F Fly Ash on the Abrasion–Erosion Resistance of High-Strength
Concrete." Construction and Building Materials 21. (2007): 458-463.
[8] Siddique, Rafat. "Effect of Fine Aggregate Replacement with Class F Fly Ash on the Abrasion Resistance of
Concrete." Cement and Concrete Research 33. (2003): 1877-1881
[9] Gesoʇlu, M., et al. "Abrasion And Freezing-Thawing Resistance of Pervious Concretes Containing Waste
Rubbers." Construction and Building Materials 73. (2014): 19-24.
[10] Thomas, Blessen Skariah, and Ramesh Chandra Gupta. "Properties of High Strength Concrete Containing
Scrap Tire Rubber." Journal of Cleaner Production 113. (2016): 86-92.