Construction and Building Materials 42 (2013) 97–104

Contents lists available at SciVerse ScienceDirect

Construction and Building Materials

journal homepage: www.elsevier .com/locate /conbui ldmat

Strength, fracture and fatigue of pervious concrete

Yu Chen a,b,⇑, Kejin Wang b, Xuhao Wang b, Wenfang Zhou a

a School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410004, Chinab Department of Civil, Construction and Environmental Engineering, Iowa State University, Ames, IA 50010, USA

h i g h l i g h t s

" The strengths of pervious concrete are much higher than what has been reported elsewhere." The paper is aimed at filling research gap on fracture and fatigue behavior of pervious concrete." Significant effect of specimen size on compressive strength of pervious concrete is found.

a r t i c l e i n f o

Article history:Received 5 April 2012Received in revised form 26 December 2012Accepted 7 January 2013Available online 13 February 2013

Keywords:Pervious concreteStrengthSize effectFracture toughnessFatigue life

0950-0618/$ - see front matter � 2013 Elsevier Ltd. Ahttp://dx.doi.org/10.1016/j.conbuildmat.2013.01.006

⇑ Corresponding author at: Department of Civil, ConEngineering, Iowa State University, Ames, IA 50010, US+1 515 294 2152.

E-mail address: just4ujust43@163.com (Y. Chen).

a b s t r a c t

Pervious concrete is increasingly used in the pavements and overlays subjected to heavy traffic and incold weather regions. In the present study, strength, fracture toughness and fatigue life of two types ofpervious concrete, supplementary cementitious material (SCM)-modified pervious concrete (SPC) andpolymer-modified pervious concrete (PPC), are investigated. The results indicate that high strength per-vious concrete (32–46 MPa at 28 days depending upon the porosity) can be achieved through both SCM-modification, using silica fume (SF) and superplasticizer (SP), and polymer-modification, using polymerSJ-601. For both SPC and PPC, porosity significantly affects compressive strength, but it has little effecton the rate of strength development. Flexural strength of pervious concrete is more sensitive to porositythan compressive strength. Pervious concrete has more significant size effect than conventional concrete.PPC demonstrates much higher fracture toughness and far longer fatigue life than SPC at any stress level.

� 2013 Elsevier Ltd. All rights reserved.

1. Introduction

Pervious concrete consists of a carefully controlled amount ofpaste and an aggregate system with a uniform particle size or anarrow particle size distribution and with little or no sand [1–3].The paste in pervious concrete forms a thick coating around theaggregate particles, binding all the particles together whileremaining a substantial amount (15–25%) of interconnectedmacro-voids in the concrete [4,5]. As a result, pervious concreteis highly permeable, having a water flow rate typically around0.34 cm/s (480 in./h).

Because of its environmental benefits, pervious concrete isincreasingly used to a variety of infrastructures, including thepavements and overlays subjected to heavy traffic and in coldweather regions. These extended applications have demanded per-vious concrete have superior strength and durability. Unfortu-nately, due to its high porosity and low cement/mortar content,

ll rights reserved.

struction and EnvironmentalA. Tel.: +1 515 708 6868; fax:

pervious concrete generally has significantly reduced strengthwhen compared with conventional concrete (CC).

Research has shown that the major factors that affect perviousconcrete strength include the concrete porosity, water-to-cementi-tious material ratio (w/cm), paste characteristic, and size and vol-ume content of coarse aggregates [5–9]. The mechanical propertiesof pervious concrete can be greatly improved by using proper con-crete materials and mix proportions [10,11]. Yang and Jiang [12]demonstrated that use of silica fume (SF) and superplasticizer(SP) could enhance pervious concrete strength substantially.Kevern [13] reported that the addition of polymer (styrene butadi-ene rubber) could improve pervious concrete workability, strength,and permeability as well as freeze–thaw resistance. In addition, theperformance of laboratory, field produced pervious concretemixtures and field cores were evaluated and compared throughlaboratory performance tests, including air voids, permeability,compressive and split tensile strengths, as well as Cantabro andfreeze–thaw durability tests by Shu et al. [14].

Although extensive work has been done, most previousresearch focuses on permeability, strength, frost resistance andabrasion resistance of pervious concrete [15–17], and limited studyhas been conducted on the fracture and fatigue behavior of

Table 3Properties of SJ-601.

Solid content (%) Viscosity (Pa s) pH Density (g/ml)

47 ± 3 0.03–0.04 5 1.08 ± 0.03

98 Y. Chen et al. / Construction and Building Materials 42 (2013) 97–104

pervious concrete, which are especially important for pavementconcrete subjected to heavy traffic and to severe seasonal temper-ature change. Being a brittle material, the mechanical behavior ofpervious concrete is critically influenced by its crack propagation,or fracture behavior. Subjecting repeated traffic and environmentalloads, concrete pavements often fail under fatigue cracking. A bet-ter understanding of fracture and fatigue behavior of pervious con-crete can help to improve pavement design procedures.

For compressive strength tests, Chinese standard GT/B 50081-2002 (standard for test method of mechanical properties in ordin-ary concrete) [18] requires using the specimen size of150 � 150 � 150 mm3. However, researchers in China often usesmaller specimens (100 � 100 � 100 mm3) for convenience. Forpervious concrete, due to the difficulties in compaction of smallspecimens, 200 � 200 � 200 mm3 specimens are sometimes used.There is little or no research on the effect of specimen size onthe pervious concrete compressive strength measurements.

The present study is aimed at filling the above-mentioned re-search gap, and it is to investigate the mechanical responses (suchas the compressive and flexural strength, fracture toughness, andfatigue properties) of the high-strength pervious concrete throughuse of supplementary cementitious materials (SCMs) or polymermodification. Besides, the effects of specimen size on the concretecompressive strength measurements are also discussed.

2. Experiment program

2.1. Materials and properties

ASTM Type I ordinary Portland cement (OPC) is used as a primary binder, and itsmajor properties are presented in Table 1. SCMs, such as Class C fly ash (CFA) and SF,are used as a cement replacement to modify the binder properties, and their prop-erties are listed in Table 2. A polymer, SJ-601, which is a mixture of vinyl acetateethylene (VAE) and acrylic emulsion, is also employed as an additive to modifythe binder properties. Table 3 lists the main properties of SJ-601. In addition, a sul-fonated naphthalene-formaldehyde condensate SP is used to improve workabilityof the pervious concrete made with OPC and SCMs.

Granite aggregate is used in all the pervious concrete mixes studied. It is a blendof two sizes of the aggregate retained on 4.75 mm sieve and 9.5 mm sieve, and theblend ratio is 4 (4.75 mm): 6 (9.5 mm).

2.2. Mix proportions

As known, the porosity of pervious concrete depends on the volume of the voidsamong the aggregate particles and the volume of paste/mortar that fills the voids.For given aggregate, with a given particle distribution and a given void ratio, thepaste amount must be reduced accordingly so as to obtain high porosity. Basedon this concept, two sets of pervious concrete mixes, (1) SCM-modified perviousconcrete (SPC) and (2) polymer-modified pervious concrete (PPC), are designed,and their mix proportions are presented in Table 4. These pervious concrete mixeshave porosity ranging from 15% to 25%. The SJ-601 dosages ranging from 8% to 12%are used based on the recommendation provided by previous research [1,19].

Table 1Properties of OPC.

Major chemical compositions (%) Specificgravity(g/cm3)

Blainefineness(m2/kg)

SiO2 Al2O3 CaO MgO Fe2O3 SO3 K2O

22.1 5.1 62.5 1.5 4.2 2.9 0.4 3.07 391

Table 2Properties of SCMs.

Major chemical compositions (%)

SiO2 Al2O3 Fe2O3 CaO MgO SO3

CFA 61.8 26.4 5.0 1.10 0.40 0.42SF 98.2 – – – – –

2.3. Specimens and test methods

Different sizes of specimens are prepared for the 21 pervious concrete mixes(12 SPC mixes and 9 PPC mixes) as described in Table 4. The specimens are testedfor the concrete porosity, compressive strength, flexural strength, fracture tough-ness, and flexural fatigue life. Table 5 lists the numbers and sizes of the specimensused for the designed tests.

To cast a cubic specimen for compressive strength test or a beam specimen forfracture and fatigue tests, a half of the steel mold (Fig. 1) is firstly filled with freshpervious concrete and placed on a standard vibration table to vibrate for 60 s. Then,while vibrating, more fresh pervious concrete is added into the mold until the moldis over-filled. This process takes approximate another 60 s. After placing and vibrat-ing, the specimen is pressed by a press machine under a pressure of 2.0 MPa for3 min. At 24 h, the mold is removed and the specimen is stored in a standard curingroom (T = 23 �C, and RH = 95%) to the designated days.

After cured for 28 days, porosity of the pervious concrete specimens is mea-sured according to the cold-water saturation method (ASTM C642, standard testmethod for density, absorption, and voids in hardened concrete [20]). The compres-sive strength tests are performed according to GT/B 50081-2002. The effect of spec-imen sizes on concrete compressive strength is investigated using three differentsizes of cubic specimens, 100 � 100 � 100 mm3, 150 � 150 � 150 mm3 and200 � 200 � 200 mm3.

Third-point loading simple beam in accordance with ASTM C78/C78M-10 [21]is conducted to assess the flexural strength, fracture toughness, and fatigue life ofpervious concrete. 40 � 40 � 160 mm3 beam specimens are notched at the midspan with a depth of 20 mm and used for fracture toughness test. The specimensare loaded under the controlled strain rate of 0.1 mm/min. The fracture toughness,KIC, stress intensity factor, is then calculated according to the following equation[22,23]:

KIC ¼PL

BH3=2 � 2:9aH

� �1=2� 4:6

aH

� �3=2þ 21:8

aH

� �5=2� 37:6

aH

� �7=2þ 38:7

aH

� �9=2� �

ð1Þ

where L, B, H represents the specimen span, width and height respectively; a is thenotch depth; and P is the maximum load.

An electro-hydraulic servo-type material testing machine is used for measuringthe flexural fatigue life of pervious concrete. Three stress levels of sine wave loading(that is 0.90, 0.80 and 0.70) with 0.1 of cycling eigenvalue, 10 Hz of frequency andzero time gaps, are adopted. The number of the cyclic load that the tested speci-mens are subjected until failure is recorded.

3. Results and discussions

3.1. Strength

Table 6 provides the compressive and flexural strengths of allthe pervious concrete mixes studied. As seen in the table, SPCand PPC mixes produced in this research all have good strengths(higher than 32 MPa), even for the mixes having porosity close to25%. More detailed analyses of the strength results are presentedbelow.

3.1.1. Strength developmentFig. 2 illustrates the difference in rates of the strength develop-

ment between SPC and PPC containing similar porosity. It is ob-served that the SPC mixes had more rapid strength developmentat early ages but slower strength development at later ages when

Specific gravity (g/cm3) Ignition loss (%)

K2O Na2O

0.80 0.54 2.37 2.07– – 1.98 0.61

Table 4Mix proportions per 1 m3 pervious concrete.

Mix ID Aggregates (kg) Cementitious materials SJ-601 (%) Water-to-binder ratio w/b

Total (kg) OPC (%) CFA (%) SF (%) SP (%)

SPC1 1450 440 80 14 6 0.2 – 0.33SPC2 1472 432SPC3 1500 416SPC4 1532 410 76 16 8 0.3 0.32SPC5 1570 394SPC6 1591 390SPC7 1611 378 0.4 0.30SPC8 1637 366SPC9 1654 345SPC10 1668 330 72 18 10 0.5 0.28SPC11 1690 325SPC12 1702 320

PPC1 1500 380 100 – – – 8 0.34PPC2 1547PPC3 1581PPC4 1606 10 0.32PPC5 1643PPC6 1677PPC7 1692 12 0.30PPC8 1700PPC9 1712

Table 5Pervious concrete specimens for designed tests.

Mix ID Number of specimens Specimen size (mm3) Tests

SPC1 � SPC12 12 � 6 150 � 150 � 150 Compressive strength at 3 days, 7 days, 14 days, 28 days, 56 days and 90 days12 150 � 150 � 550 Flexural strength at 28 days1 40 � 40 � 160 Flexural fracture toughness at 28 days6 � 3 100 � 100 � 400 28-day flexural fatigue at 3 stress levels12 100 � 100 � 100 Compressive strength at 28 days12 200 � 200 � 200

PPC1 � PPC9 9 � 6 150 � 150 � 150 Compressive strength at 3 days, 7 days, 14 days, 28 days, 56 days and 90 days9 150 � 150 � 550 Flexural strength at 28 days2 40 � 40 � 160 Flexural fracture toughness at 28 days6 � 3 100 � 100 � 400 28-day flexural fatigue at 3 stress levels

Fig. 1. Steel moulds used to cast pervious concrete specimens.

Y. Chen et al. / Construction and Building Materials 42 (2013) 97–104 99

compared with the PPC mixes. The rapid strength development ofthe SPC mixes at early ages may be contributed to the use of SF to-gether with SP. The aggregate particles are rapidly wrapped andcemented together by a stiff paste to form the skeleton-pore struc-ture, obtaining quite strong resistance to the destructive load atearly ages. However, due to the small amount of cementitiouspaste used and slow hydration process, there is no remarkablestrength gain at later ages (Fig. 2a).

In the PPC mixes, cement hydration at early ages may be re-tarded due to the addition of the polymer SJ-601, the particles ofwhich may adsorb on the cement particle surfaces and preventthe cement from contacting with water. Because of high relative

humidity in the paste, the polymer particles are also difficult toaggregate. Therefore, neither cement nor polymer can develop suf-ficient strength at early ages. However with time, the layer of thepolymer coated on cement particles is destroyed by Brownian mo-tion of water molecular and/or by the redistribution of graduallyproduced cement hydration products. As a result, more cementstarts to hydrate. At the same time, the polymerization of SJ-601speeds up with the decreasing relative humidity in the paste. Thus,cement hydration products and polymer films begin to intertwine,interpenetrate, and build up a network microstructure that canfirmly bind aggregate particles together, shown as Fig. 3. The syn-ergetic effect of cement particles and polymer particles provides

Table 6Results of strength test.

Mix ID Porosity (%) Compressive strength (MPa) Flexural strengthat 28 days (MPa)

Ratio of flexural to compressivestrength at 28 days

3 days 7 days 14 days 28 days 56 days 90 days

SPC1 15.2 23.8 38.3 42.6 46.7 48.1 49 6.1 0.131SPC2 16.3 24.8 36.1 40.6 45.1 48.1 49.1 5.9 0.131SPC3 17.6 23.9 35.9 38.5 43.3 45.5 46.3 5.6 0.13SPC4 18.4 26 34.2 40.6 42.7 48.7 51.1 5.4 0.127SPC5 18.9 22.7 34.4 37.8 42 44.5 45.8 5.4 0.129SPC6 19.5 24.8 35.6 38.2 41.4 43.5 46 5.3 0.128SPC7 20.1 21 32.8 36.5 40.5 41.7 43.3 5.1 0.127SPC8 21.1 19.7 32.7 35.9 39.4 42.2 43 5 0.127SPC9 22.8 22.2 31.5 36.2 38.9 40.4 42 4.8 0.124SPC10 23.2 22.6 33.1 33.8 37.6 41 41.9 4.7 0.125SPC11 24 19.1 28.8 34 36 37.1 38.5 4.4 0.121SPC12 24.7 20.4 29.9 32.4 35.2 36.3 36.7 4.2 0.119

PPC1 15.8 11.8 22.4 30.7 43.9 50.9 51.8 7.3 0.166PPC2 17 13.1 19.1 32.2 43.5 48.7 50.5 7.4 0.157PPC3 19.3 13.2 17.8 29.4 42.7 48.6 48.7 7 0.163PPC4 19.7 11.5 18.9 28.8 41.2 47.2 48.9 7.2 0.17PPC5 21.2 14.7 20.3 31.2 40.5 44.1 46.7 6.3 0.156PPC6 22.5 11.5 15.7 28.3 38.2 43.9 44.3 6.2 0.162PPC7 23.4 9.2 16.1 26 36.6 39.9 41.0 5.5 0.151PPC8 24.3 9.8 13.5 24.3 33.7 39.6 40.1 5 0.149PPC9 25 9.6 15.1 21.8 32.1 38.2 39.2 4.8 0.148

0

10

20

30

40

50

60

0 7 14 21 28 35 42 49 56 63 70 77 84 91

Age (days)

Com

pres

sive

str

engt

h (M

Pa)

SPC1: 15.2% of porosity

SPC6: 19.5% of porosity

SPC12: 24.7% of porosity

(a) SPC

0

10

20

30

40

50

60

0 7 14 21 28 35 42 49 56 63 70 77 84 91

Age (days)

Com

pres

sive

str

engt

h (M

Pa)

PPC1: 15.8% of porosity

PPC4: 19.7% of porosity

PPC9: 25.0% of porosity

(b) PPC

Fig. 2. Compressive strength development of SPC and PPC with different porosity.

Fig. 3. Microstructure of the matrix in PPC.

100 Y. Chen et al. / Construction and Building Materials 42 (2013) 97–104

PPC evident strength growth after 14 days. At later ages such as 56and 90 days, the further improved strength of PPC may be attrib-uted to the pore refinement, resulting from the aggregated poly-mer particles and cement hydration products that keep fillingmicro-pores in the paste, and attributed to the paste–aggregate

bond improvement in the concrete, resulting from the strong,cohesive polymer modified paste.

It is worth to note that to benefit both cement hydration and SJ-601 polymerization, it is favorable for PPC to be wet-cured at least3 days to promote cement hydration, and then to be stored at a dryenvironment with relative humidity less than 70% for a better filmformation of the polymer.

3.1.2. Effects of concrete porosityFig. 4 demonstrates the effect of porosity on strength of the SPC

and PPC mixes. As observed in the figure, although porosity plays acrucial role in controlling pervious concrete strength, it appears tohave less effect on concrete strength at the early ages (3 and7 days, Fig. 4a and b) when compared with at the later ages (28,56 and 90 days, Fig. 4d–f).

Fig. 4 also shows that SPC gains strength much more rapidlythan PPC before the age of 14 days. As the time passed, the strengthdifference between SPC and PPC becomes smaller with concrete

0

5

10

15

20

25

30

Porosity (%)

Com

pres

sive

str

engt

h (M

Pa)

SPC PPC

(a) at 3 days

0

5

10

15

20

25

30

35

40

45

Porosity (%)

Com

pres

sive

str

engt

h (M

Pa)

SPC PPC

(b) at 7 days

0

5

10

15

20

25

30

35

40

45

Porosity (%)

Com

pres

sive

stre

ngth

(MPa

)

SPC PPC

0

5

10

15

20

25

30

35

40

45

50

Porosity (%)

Com

pres

sive

str

engt

h (M

Pa)

SPC PPC

(d) at 28 days

0

5

10

15

20

25

30

35

40

45

50

55

Porosity (%)

Com

pres

sive

str

engt

h (M

Pa)

SPC PPC

0

5

10

15

20

25

30

35

40

45

50

55

14 16 18 20 22 24 26

14 16 18 20 22 24 26

14 16 18 20 22 24 26

14 16 18 20 22 24 26

14 16 18 20 22 24 26

14 16 18 20 22 24 26

Porosity (%)

Com

pres

sive

str

engt

h (M

Pa)

SPC PPC

(f) at 90 days (c) at 14 days

(e) at 56 days

Fig. 4. Compressive strength of SPC and PPC at different ages.

Y. Chen et al. / Construction and Building Materials 42 (2013) 97–104 101

curing age. At the age of 28 days, there is little or no difference instrength between SPC and PPC. At the later ages (56 and 90 days),the strength of PPC is slightly higher than that of SPC.

To further evaluate the rate of the pervious concrete strengthdevelopment, the compressive strengths of all mixes are also ex-pressed as a percentage of their 28-day strength as shown inFig. 5. It is observed that at a given age, the strength percentagesof specimens made with different mixes, or with different porosity,are very close. That is, porosity does not significantly affect the rateof both SPC and PPC strength development.

3.1.3. Relationship between compressive and flexural strengthAs seen in Table 6, PPC has evidently higher flexural strength

than SPC at the same porosity level, and the ratios of flexural tocompressive strength of the PPC mixes are also much higher than

those of the SPC at 28 days. A possible reason is that polymer SJ-601 strengthens both the interfacial transition zone (ITZ) betweenthe paste and aggregate and the matrix microstructure of perviousconcrete, and makes the concrete less brittle, thus having excellentresistance to flexural damage. With the increasing of porosity, bothflexural and compressive strengths decrease, however, the mostideal trend lines in Fig. 6 exemplify that the ratios of flexural-to-compressive strength of SPC and PPC definitely decrease too. Soit suggests that the flexural strength of pervious concrete may bemore sensitive to porosity change than the compressive strength.

3.1.4. Effect of specimen size on compressive strengthTest results of the 28-day compressive strength of cubic

specimens with different sizes are presented in Table 7. A sizeconversion factor (d) is calculated as the ratio of the 28-day com-

0

20

40

60

80

100

120

140

Age (days)

Stre

ngth

per

cent

age

(%)

SPC1 SPC2 SPC3 SPC4

SPC5 SPC6 SPC7 SPC8

SPC9 SPC10 SPC11 SPC12

(a) SPC

0

20

40

60

80

100

120

140

0 7 14 21 28 35 42 49 56 63 70 77 84 91

0 7 14 21 28 35 42 49 56 63 70 77 84 91

Age (days)

Stre

ngth

per

cent

age

(%)

PPC1 PPC2 PPC3PPC4 PPC5 PPC6PPC7 PPC8 PPC9

(b) PPC

Fig. 5. Strength development process of pervious concrete.

0.10

0.11

0.12

0.13

0.14

0.15

0.16

0.17

0.18

14 16 18 20 22 24 26

Porosity /%

Rat

io o

f fle

xura

l to

com

pres

sive

str

engt

h

SPC

PPC

Fig. 6. Ratios of flexural to compressive strength of pervious concrete.

102 Y. Chen et al. / Construction and Building Materials 42 (2013) 97–104

pressive strength (f 0c;0) of the specimens with standard size(150 � 150 � 150 mm3) to the 28-day compressive strength (f 0c)of the specimens with non-standard size (100 � 100 � 100 mm3

or 200 � 200 � 200 mm3). That is, d ¼ f 0c;0=f 0c . (Note:150 � 150 � 150 mm3 is a standard size of specimens to be usedfor compressive strength test as prescribed in GB/T 50081-2002).

For conventional concrete, it is specified by GB/T50081-2002that the size conversion factors are 0.95 when 100 � 100 �100 mm3 specimens are used and 1.05 when 200 � 200 �200 mm3 specimens are used for compressive strength tests.Table 7 evidences the clear size effect of pervious concrete oncompressive strength because the size conversion factors (d) of100 � 100 � 100 mm3 specimens are all much lower than 0.95,

while those of 200 � 200 � 200 mm3 specimens are all much high-er than 1.05 for all SPC mixes. Since no sufficient mortar/paste tofill the voids between aggregate particles, pervious concrete hasmuch more significant size effect than conventional concrete, espe-cially when porosity of pervious concrete is high.

Fig. 7 shows that the size conversion factor (d) of specimenschanges with pervious concrete porosity. From the data regression,the exponential function lines are derived as follows and displayedin Fig. 7:

For 100 � 100 � 100 mm3 specimens,

d ¼ 1:111e�0:012p; R2 ¼ 0:9417 ð2Þ

For 200 � 200 � 200 mm3 specimens,

d ¼ 0:9862e0:0058p; R2 ¼ 0:9218 ð3Þ

where d is the size conversion factor, and p means the porosity ofpervious concrete.

When the non-standard cubic specimens are used for compres-sive strength test of pervious concrete, the size conversion factorcan be determined using Eqs. (2) and (3).

3.2. Fracture toughness

The mixes with similar porosity (i.e. around 19.5%), such asmixes SPC6, PPC3 and PPC4, are chosen to be tested for the fracturetoughness. Among these mixes, PPC3 and PPC4 mixes have 8% and10% of polymer SJ-601 addition, respectively, and SPC6 has nopolymer addition. The fracture toughness results are given in Table8. It can be seen that the fracture toughness of pervious concreteapparently increases with the increasing of polymer dosage. Incomparison with SPC6, the fracture toughness of PPC3 and PPC4 in-creases 45.3% and 56.9% respectively. This implies that addition ofthe polymer improves the concrete resistance to cracking andcrack propagation, and therefore it requires more fracture energyto fracture PPC than to fracture SPC.

Besides, the improvement of PPC fracture toughness can also beattributed to that SJ-601 particles gather and polymerize in the re-gion of ITZ with the polymer films tightly bonding the cementpaste matrix and aggregate together, as illustrated in Fig. 8. Differ-ent from conventional pervious concrete, which generally fracturesaround aggregate particles due to the weak ITZ between the aggre-gate and paste, PPC fractures through aggregate particles, whichindicates a good bond between aggregate and paste.

3.3. Flexural fatigue property

Results from the flexural fatigue tests of selected SPC and PPCmixes are listed in Table 9. It is found that PPC has by far longerflexural fatigue life than SPC at all stress levels, since the polymerhelps reduce cracking or delay cracking growth. In Fig. 9, the mostideal trend lines based on the calculated data from Eq. (4) illus-trates that for both SPC and PPC mixes, the fatigue lives decreasewith the increasing porosity and the stress level sustained by thespecimens. There exists an excellent linear relationship betweenthe fatigue life of pervious concrete and its porosity.

Fatigue life of a concrete material is often expressed by a two-parameter Weibull probability function [15,16]. In general, two-parameter Weibull probability function is established as:

LnS ¼ Lna� cLnN ð4Þ

where S refers to the stress level sustained by concrete specimen; aand c are coefficients related to the concrete material properties. Nmeans the number of cyclic loads sustained by concrete specimenat any stress level before failure.

Table 728-day compressive strength of SPC specimens with different sizes.

Mix ID 100 � 100 � 100 mm3 150 � 150 � 150 mm3 200 � 200 � 200 mm3

f 0c (MPa) d f 0c;0 (MPa) d f 0c (MPa) d

SPC1 50.7 0.921 46.7 1.000 43.4 1.076SPC2 48.8 0.924 45.1 41.8 1.079SPC3 47.7 0.908 43.3 39.9 1.085SPC4 46.9 0.910 42.7 39.1 1.092SPC5 46.7 0.899 42.0 38.1 1.102SPC6 47.5 0.872 41.4 37.2 1.113SPC7 46.3 0.875 40.5 36.2 1.119SPC8 45.9 0.858 39.4 35.2 1.119SPC9 45.5 0.855 38.9 34.7 1.121SPC10 44.4 0.847 37.6 33.4 1.126SPC11 43.0 0.837 36.0 31.9 1.129SPC12 42.1 0.836 35.2 31.0 1.135

Note: f 0c – 28-days compressive strength of 100 mm or 200 mm cubic specimen;f 0c;0 – 28-days compressive strength of 150 mm cubic specimen;d – The size conversion factor, d = f 0c;0/ f 0c .

0.80

0.84

0.88

0.92

0.96

1.00

1.04

1.08

1.12

1.16

14 16 18 20 22 24 26

Porosity (%)

Size

con

vers

ion

fact

or

100mm cube

200mm cube

Fig. 7. Size conversion factor (d) of specimens with different porosity.

Table 8Effect of polymer on fracture toughness of pervious concrete.

Mix ID SJ-601 (%) P (N) KIc (MPa m1/2)

SPC6 0 289 0.327PPC3 8 390 0.475PPC4 10 440 0.513

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

14 16 18 20 22 24 26

Porosity (%)

LnN

SPC; 0.9 of stress level

PPC; 0.9 of stress level

SPC; 0.8 of stress level

PPC; 0.8 of stress level

SPC; 0.7 of stress level

PPC; 0.7 of stress level

Fig. 9. Relationship of LnN and porosity of pervious concrete.

Fig. 8. Microstructure of ITZ in PPC.

Table 9Number (N) of cyclic loads sustained by pervious concrete before failure.

Mix ID Stress levels of SPC Mix ID Stress levels of PPC

0.90 0.80 0.70 0.90 0.80 0.70

SPC1 651 15,311 230,158 PPC1 1054 20,014 604,121SPC3 478 10,178 101,134 PPC3 815 14,331 371,580SPC5 379 70,145 57,894 PPC4 707 12,067 248,741SPC8 295 3422 31,490 PPC6 426 9015 112,055SPC10 204 930 20,158 PPC7 315 3088 30,851SPC12 107 395 8345 PPC9 187 801 12,334

Y. Chen et al. / Construction and Building Materials 42 (2013) 97–104 103

Based on test data listed in Table 9, the two-parameter Weibullprobability functions of both SPC and PPC under different failureprobabilities can be derived. Zheng et al. [24] provided the sametwo-parameter Weibull probability functions of some typical con-crete materials, including conventional concrete, lean concrete,and conventional pervious concrete under 50% of failure probabil-ity (Fig. 10). To compare with previous study, the functions of SPCand PPC under 50% of failure probability are also illustrated inFig. 10. Each line represents the typical two-parameter Weibullprobability distribution of different concretes under 50% of failureprobability. It appears that for the same failure probability, con-ventional concrete has the longest fatigue life, followed by leanconcrete; while pervious concrete generally has much shorter fati-gue life. However, when compared with conventional perviousconcrete [24], the high-strength SPC and PPC presented in thisstudy have quite longer fatigue lives. Besides, it seems that the fa-tigue property of PPC can be comparable to or even higher thanthat of lean concrete, especially at low stress levels.

-0.50-0.45-0.40-0.35-0.30-0.25-0.20-0.15-0.10-0.050.000.05

0 1 2 3 4 5 6 7 8

LnN

LnS

Conventional concrete

Lean concrete

conventional pervious concrete [19]

PPC

SPC

Fig. 10. LnS–LnN of different concretes under 50% of failure probability.

104 Y. Chen et al. / Construction and Building Materials 42 (2013) 97–104

4. Conclusions

Compressive and flexural strength, fracture toughness, andfatigue life of two types of pervious concrete, (1) SCM-modifiedpervious concrete (SPC) and (2) polymer-modified pervious con-crete (PPC), are investigated. The following conclusions can bedrawn:

(1) High strength pervious concrete, 32–46 MPa at 28 daysdepending upon the porosity, can be achieved through bothSCM-modification using silica fume (SF) and superplasticizer(SP), and polymer-modification, using polymer SJ-601.

(2) For both SPC and PCC, porosity significantly affects compres-sive strength of pervious concrete, but it has little effect onthe rate of strength development. SPC gains compressivestrength rapidly at early ages, while its strength incrementsare rather low after 28 days. Differently, PPC gains strengthslowly at early ages, but its development accelerates at laterages, probably due to the continuous hydration of cementand film-forming of polymer materials.

(3) PPC has both higher flexural strength and higher flexural-to-compressive strength than SPC at the same porosity level at28 days. The ratios of flexural-to-compressive strength ofboth PCC and SPC decrease with increasing porosity, whichindicates that flexural strength is more sensitive to porositythan compressive strength of pervious concrete.

(4) Pervious concrete has more significant size effect than con-ventional concrete. The size conversion factors (d) for100 � 100 � 100 mm3 specimens and for 200 � 200 �200 mm3 specimens recommended from the present studymay be considered in future when different size cubicspecimens are used for the compressive strength tests ofpervious concrete.

(5) Both high-strength SPC and PPC produced in this study haveimproved fatigue property than conventional pervious con-crete. PPC displays much higher fracture toughness and farlonger fatigue life than SPC at any stress level, which sug-gests that PPC has improved resistance to cracking and crackpropagation.

Acknowledgements

The present study is sponsored by the Department of HunanHighway Administration. All experiments are carried out in KeyLaboratory of Ministry of Transportation for Road Materials andStructures in Changsha University of Science and Technology.

References

[1] Chen Y, Zhang Q, Gao Y. Manufacturing technology of porous cement concretefor highway construction. Geotechnical Special Publication, Road PavementMaterial Characterization and Rehabilitation, ASCE 2009;191:22–33.

[2] Marolf A, Neithalath N, Sell E, Wegner K, Weiss J, Olek J. The influence ofaggregate size and gradation on acoustic absorption of enhanced porosityconcrete. ACI Mater J 2004;101(1):82–91.

[3] Park SB, Seo DS, Lee J. Studies on the sound absorption characteristics of porousconcrete based on the content of recycled aggregate and target void ratio. CemConcr Res 2005;35(9):1846–54.

[4] Neithalath N. Extracting the performance predictors of enhanced porosityconcretes from electrical conductivity spectra. Cem Concr Res2007;37(5):796–804.

[5] Chindaprasirt P, Hatanaka S, Chareerat T, Mishima N, Yuasa Y. Cement pastecharacteristics and porous concrete properties. Constr Build Mater2008;22(5):894–901.

[6] Schaefer VR, Wang K, Sulieman MT, Kevern JT. Mix design development forpervious concrete in cold weather climates. Final report, Iowa Department ofTransportation, National Concrete Pavement Technology Center, IowaConcrete Paving Association; 2006.

[7] Ghafoori N. Development of No-fines concrete pavement applications. J TranspEng 1995;121(3):283–8.

[8] Deo O, Neithalath N. Compressive behavior of pervious concretes and aquantification of the influence of random pore structure features. Mat Sci EngA-Struct 2010;528(1):402–12.

[9] Crouch LK, Pitt J, Hewitt R. Aggregate effects on pervious Portland cementconcrete static modulus of elasticity. J Mater Civil Eng 2007;19(7):561–8.

[10] Sumanasooriya MS, Neithalath N. Pore structure features of pervious concretesproportioned for desired porosities and their performance prediction. CemConcr Compos 2011;33(8):778–87.

[11] Huang B, Wu H, Shu X, Dong Q, Burdette EG. Laboratory evaluation ofpermeability and strength of polymer-modified pervious concrete. ConstrBuild Mater 2010;24(5):818–23.

[12] Yang J, Jiang G. Experimental study on properties of pervious concretepavement materials. Cem Concr Res 2003;33(3):381–6.

[13] Kevern JT. Advancement of pervious concrete durability. Ph.D. dissertation,Iowa State University, Ames, IA; 2008.

[14] Shu X, Huang B, Wu H, Dong Q, Burdette EG. Performance comparison oflaboratory and field produced pervious concrete mixtures. Constr Build Mater2011;25(8):3187–92.

[15] Li QS, Fang JQ, Liu DK, Tang J. Failure probability prediction of concretecomponents. Cem Concr Res 2003;33(10):1631–6.

[16] Singh SP, Kaushik SK. Fatigue strength of steel fibre reinforced concrete inflexure. Cem Concr Compos 2003;25(7):779–86.

[17] Wu H, Huang B, Shu X, Dong Q. Laboratory evaluation of abrasion resistance ofPortland cement pervious concrete. ASCE 2011;23(5):697–702.

[18] GT/B 50081–2002. Standard for test method of mechanical properties inordinary concrete. Ministry of Housing and Urban-Rural Development of China(MOHURD); 2002.

[19] Chen Y. Study on high-performance porous cement concrete pavement for lowtraffic highway tunnel. Ph.D. thesis, Changsha: Center South University; 2007.

[20] ASTM C642–97. Standard test method for density, absorption, and voids inhardened concrete. American society for testing and materials; 1997.

[21] ASTM C78/C78M-10. Standard test method for flexural strength of concrete(using simple beam with third-point loading). American society for testing andmaterials; 2010.

[22] Wu Z, Zhao G, Huang C. Fracture toughness and fracture energy for differentconcrete strength. J Dalian Univ Technol 1993;27(2):15–21 [in Chinese].

[23] Sheng X, Huang Z. Experimental study and theory on fracture ofconcrete. Beijing: China Waterpower Press; 2008 [in Chinese].

[24] Zheng M, Wang B, Hu C. Study of fatigue property of porous concrete. China JHighway Transp 2004;17(4):7–11 [in Chinese].