Construction and Building Materials 98 (2015) 51–60
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Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat
Material design and characterization of high performance pervious concrete Rui Zhong, Kay Wille
⇑
Department of Civil and Environmental Engineering, University of Connecticut, 261 Glenbrook Road, Unit 3037, Storrs, CT 06269-3037, United States
h i g h l i g h t s
Development of high performance pervious concrete (HPPC) to advance and broaden the application of pervious concrete. Increase of strength and durability without sacrificing the hydraulic conductivity through tailored mix design. Use of ultra-high performance matrix for pervious concrete design. Material characterization regarding compressive behavior, hydraulic conductivity and freeze–thaw resistance.
a r t i c l e
i n f o
Article history: Received 5 June 2015 Received in revised form 3 August 2015 Accepted 6 August 2015 Available online 24 August 2015 Keywords: Pervious concrete High performance Compressive strength Hydraulic conductivity Durability Freeze–thaw Porosity
a b s t r a c t
Continued Continued urbanization urbanization and population population growth further the growth growth of impervious impervious urban areas, leading to concerning adverse environmental and societal impacts. Pervious concrete has remarkable potential to counteract counteract these adverse adverse impacts impacts while providing providing necessary necessary structural structural integrity, integrity, thus supporting supporting continued urbanization. Broader application of pervious concrete could be achieved through increased raveling resistance and enhanced durability performance. This research emphasizes the development and characterization of high performance pervious concrete aiming at improved mechanical resistance and advanced durability durability properties. properties. In pursuit pursuit of this goal an ultra-hig ultra-high h performanc performance e cement-bas cement-based ed matrix matrix with compressive compressive strengths strengths in excess excess of 150 MPa (22 ksi) ksi) and high durability durability properties properties are designed and applied to the mixture design concept of pervious concrete. The research results show that compressive compressive strength strength and elastic modulus increase by up to 150% and 100%, respectively, respectively, without without sacrificing sacrificing the hydraulic hydraulic conductivity conductivity of the concrete. concrete. Furthermore, Furthermore, freeze–thaw freeze–thaw tests have been carrie carried d out to compar compare e the durabi durabilit lity y perfor performan mance ce of conven conventio tional nal pervio pervious us concre concrete te with with high high perfor performan mance ce pervio pervious us concre concrete. te. Based Based on enh enhanc anced ed mechan mechanica icall proper propertie tiess as well well as improv improved ed durabi durabilit lity, y, high high perfor performan mance ce pervio pervious us concre concrete te potent potential ially ly allows allows extend extending ing the applic applicati ation on of pervio pervious us concre concrete te and thus thus carrie carriess a vital vital potent potential ial in effect effective ively ly counte counterac ractin ting g the growth growth of imperviou imperviouss urban areas. 2015 Elsevier Ltd. All rights reserved.
1. Introduction By 2050 continued growth of population and urbanization will potentially add 2.5 billion people to the world’s urban population [1].. This trend presses the extension of urban areas and accompa[1] nying impermeable surfaces. Pervious concrete (PC), also referred to as porous or permeable concrete, is a porous media which primarily marily consists consists of open-grad open-graded ed aggregate aggregatess bonded bonded by cementcementbased matrix. The connected pores, typically in the range of 15% to 30% per volume, ‘‘allow air and fluids to pass easily from the Corresponding author. E-mail addresses:
[email protected] addresses:
[email protected] (R. (R. Zhong),
[email protected] Zhong),
[email protected] (K. Wille). ⇑
http://dx.doi.org/10.1016/j.conbuildmat.2015.08.027 0950-0618/ 2015 Elsevier Ltd. All rights reserved.
surface to underlying layers” [2] leading to the following features in comparison to conventional impervious concrete (Fig. ( Fig. 1): 1): Environme Environmentall ntally y friendly friendly potential potential combined combined with enhanced enhanced traffic safety [3–12] promotes [3–12] promotes pervious concrete as construction material material for parking parking lots and road surfaces. surfaces. However, However, broader broader application of pervious concrete could be achieved through mitigating the following three risks: Risk
of clogging by organic and inorganic material reduces the hydraulic conductivity. Limited bond strength strength between between the aggregate aggregatess increases increases the Limited risk of surface raveling, excessive cracking and wearing, leading to accelerated deterioration especially under high-volume and heavy load traffic.
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Fig. 1. Comparison of pervious concrete to impervious concrete.
High
proportion of material surface area exposed to environmental aggressors increases the risk of loss of structural integrity due to reduced durability.
UHPM. Fig. UHPM. Fig. 3 illustrates 3 illustrates the packing density of matrices of different performance levels.
I. Empl Employm oyment ent of optimi optimized zed ultraultra-hig high h perfor performan mance ce matrix matrix.. Ultra-high performance matrix (UHPM) is replacing conventional matrix to cover the aggregate and bind them together (Fig. 2). 2).
II. Enhanced interfacial transition zone (ITZ) between matrix and aggregate. aggregate. This is achieved achieved through through the incorporation incorporation of silica fume and the use of MPEG type polycarboxylate ether (PCE) based high range water reducer (HRWR). Silica fume densifies the matrix through pozzolanic reaction and filler effect (Fig. (Fig. 4). 4). MPEG type PCE is able to efficiently disperse the fine partic particle le system system due to its balan balanced ced affinity affinity to cement, silica fume and silica powder [18] [18].. This enables w/ c rati ratio o as low low as 0.2 0.2 lead leadin ing g to dens densifi ifica cati tion on of the the microstructure. III. Balanced aggregate to binder (A/B) ratio and tailored aggregate size. size. High performance performance pervious concrete concrete (HPPC) (HPPC) aims at higher bond strength (indirectly evaluated by the compressive strength of the material) without sacrificing its functional tional requir requireme ement nt to allow allow water water penetr penetrati ating ng throug through. h. Higher amount of matrix (lower A/B ratio) leads to reduced total porosity and hydraulic conductivity but higher compressive strength whereas lower amount of matrix (higher A/B ratio) results in increased total porosity and hydraulic conductivity but lower compressive strength. Additionally, the aggregate aggregate size affects affects the pore system character characteristic isticss (total porosity, pore size and its distribution) and thus the compre compressi ssive ve streng strength th and hydrau hydraulic lic conduc conductiv tivity ity [19]. [19]. Therefore a balanced A/B ratio and tailored aggregate size are necessary to satisfy both of the competing performance criteria.
Based on prior research [17] the incorporation of silica fume (SF) and ultra-fine silica powder (SP) in tailored proportion significantly improves the packing density of the fine particle system of
Other approaches, such as reduction in A/B ratio, incorporation of supplementary cementitious materials (SCMs), and addition of fine sand or polymer modification of matrix, are also employed
Research Research on long-term long-term surface permeability permeability has shown that clogging particles asymptotically reduce the permeability, albeit to an infil infiltr tra ation tion rate rate stil stilll con consid sidere ered to be high high [13]. [13]. Additionally research results point out that the loss of permeability depends on the clogging particle size to pore size ratio, leading to losses in the range of negligible to 80% [14] 80% [14].. On-site experience has also also sho shown wn that that cloggi clogging ng can be suc succes cessfu sfully lly minimi minimized zed with with proper proper mater material ial instal installat lation ion and mainte maintenan nance ce using using vacuu vacuum m sweeping or pressure cleaning [15,16] [15,16].. While clogging of pervious concrete becomes less concerning, its limited bond strength and durability properties remain an unresolved issue. Motivated by the application potential of pervious concrete and the potential benefits of enhancing bond strength and durability properties, this research emphasizes the development of high performance pervious concrete. 2. Conceptual approach The following following principles principles are followed followed to design design high perforperformance pervious concrete (HPPC):
Fig. 2. Schematic comparison of pervious concrete employing different matrices.
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Fig. 3. Illustration of packing density of matrices of different performance levels.
(a) NSM
(b) UHPM
Fig. 4. Microstructure of different matrices (7 days) using SEM.
Table 1
Matrix proportion and compressive strength. Constituent
3. Experimental study Proportions by weight
Cement Silica fume Silica powder Water HRWR Compressive strength (MPa)
3.1. Materials
UHPM
NSM
1 0.25 0.25 0.22 0.036 174
1 0.00 0.00 0.55 0.000 29
by researchers to improve the bond between the aggregates and therefore the compressive strength of pervious concrete. Detailed discussion is presented in the following section.
Based on prior research results on material design of ultra-high performance concrete [17] [17] and and on high performance performance pervious concrete concrete (HPPC) [19] (HPPC) [19],, the following materials are recommended: Portland
cement type I with a high C3S content (here 74%), a moderate fineness (here 3930 cm2/g Blaine value), a low C3 A content (here 5%) and meeting ASTM C150 standard specification for Portland cement. Silica fume with a very low carbon content (here 0.3%). The median particle size of SF used for this research is 0.4 lm. Supplem Supplemental ental material material with median particle size between between silica fume and cement. Silica powder with a median particle size of 1.7 lm was used in this research.
Table 2
Mixture proportions for mechanical properties test.
a
Series
Mixture IDa
A/B
Aggregate size (mm)
Matrix strength (MPa)
HPPC
UHPM-2.5-1.19 UHPM-3.0-1.19 UHPM-3.5-1.19 UHPM-2.5-4.75 UHPM-3.0-4.75 UHPM-3.5-4.75
2.5 3.0 3.5 2.5 3.0 3.5
1.19 1.19 1.19 4.75 4.75 4.75
174 174 174 174 174 174
PC
NSM-2.5-1.19 NSM-3.0-1.19 NSM-3.5-1.19 NSM-2.5-4.75 NSM-3.0-4.75 NSM-3.5-4.75
2.5 3.0 3.5 2.5 3.0 3.5
1.19 1.19 1.19 4.75 4.75 4.75
29 29 29 29 29 29
Identifications start with the type of matrix, followed by the aggregate to binder ratio (A/B) and the aggregate size size d. d.
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Table 3
Mixture proportions and test conditions of matrices for F–T test. Series
Mixture IDa
Test condition
NSM
NSM-P NSM-F
Partially submerged Fully submerged
UHPM
UHPM-P UHPM-F
Partially submerged Fully submerged
a
Mix identifications starts with the type of matrix, followed by test condition. P and F stand for partially and fully submerged, respectively.
Table 4
Mixture proportions and test conditions of pervious concrete for F–T test. Series
Mixture IDa
M at at ri ri x
T es es t c on on di di ti ti on on
PC
NSM-3.0-1.19-P NSM-3.0-1.19-F
NSM NSM
Partially submerged Fully submerged
HPPC
UHPM-3.0-1.19-P UHPM- 3 3..0-1.19- F
UHPM UHPM
Partially submerged Fully submerged
Fig. 6. Pervious concrete compression test setup.
a
Mix identifications starts with the type of matrix, followed by the aggregate to binder ratio A/B, aggregate size in millimeter and test condition. P and F stand for partially and fully submerged, respectively.
MPEG
type polycarboxylate ether (PCE) high range water reducer (HRWR). aggregate with 99% content of silicon dioxide.
Washed
The proportions of the matrices are summarized in Table in Table 1. 1. 3.2. Mixture proportion 3.2.1. For mechanical properties test In total 12 mixtures were proportioned with varying matrix strength, aggregate to binder ratio (A/B) by weight and aggregate size. Binder is defined here as the sum of all fine powders, water and admixtures. The mixture proportions are listed in Table 2. 2. 3.2.2. For freeze–thaw durability test Specimens with varying matrix type (NSM and UHPM) and test condition (partially or fully submerged) were prepared to investigate the freeze–thaw (F–T) resistance of pervious concrete. Tables concrete. Tables 3 and 3 and 4 4 summarize summarize the mix proportions and test conditions (partially or fully submerged) of the matrices and pervious concrete for F–T test, respectively. Partially submerged was achieved by adjusting the water level to half of the specimen height. Fig. 7. Schematic definition of linearity and energy absorption capacity. 3.3. Specimen preparation and test method 3.3.1. Compressive strength test The compressive strength of matrix was determined in accordance with ASTM C109/C109M-13. Loading faces of the cubic specimen were ground before testing to assure plane surface and thus high consistency of test results (Fig. (Fig. 5). 5). The compressive strength of pervious concrete was determined following ASTM C39 with displacement controlled load application at a rate of 0.5 mm/min. About 6 mm (1/4 inch) was cut from each load surface of the cylinder (6 inch in height and and 3 inch inch in diam diamet eter er). ). Both Both ends ends were were sulf sulfur ur capp capped ed prio priorr to test testin ing. g. Longitudinal displacement was measured by three LVDTs as shown in Fig. in Fig. 6. 6. For each specimen a stress versus strain curve was obtained from which the compressive strength, elastic modulus, strain at peak stress, and energy absorption capacity capacity were calculated calculated.. The energy absorption capacity capacity is defined defined as the area
a) Before grinding
b) After 60 sec.
under under the stress stress versus versus strain strain curve up to the strain strain at peak peak stress stress (Fig (Fig.. 7). Furthermore linearity of the ascending part was determined using Eq. (1) Eq. (1) following following ASTM C469M. k ¼ E t t =E s
ð1Þ
3.3.2. Porosity and hydraulic conductivity test The procedure for porosity test has been reported in prior research and interested readers are referred to [19] to [19] for for detailed information. Since the hydraulic conductivity of pervious concrete (>103 m/s) is several orders of magnitude larger than conventional impervious concrete (<1012 m/s) due to the large volume and
c) After 3 min.
d) UHPM cube under test
e) Debris from tested UHPM cube
Fig. 5. Specimen preparation (cube 50 50 50 mm [2 2 2 in.]) and failure of UHPM.
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Fig. 8. Hydraulic conductivity test rig. interconnec interconnected ted pore system, system, convention conventional al methods methods used to measure measure the water water transport property of normal concrete are not applicable. A constant head permeameter was designed in the laboratory. The basic design consisted of a 102 mm diameter clear PVC pipe ‘‘U” shape assembly as shown in Fig. 8. 8. The specimens were cut one inch inch from from each each end and sealed sealed by shrink shrink wrap to preven preventt latera laterall penetration. The outflow of the system over time was tracked by an ADAM CBK Model Scale with 16 kg capacity and 0.0005 kg precision. AdamDU data acquisition software was used to record the data continuously over 45 s. Three minutes were allowed after the start of the test to let the system reach dynamic equilibrium. From each experimental data set, the middle 35 s were selected as subset for calculating the flow rate of water. water. Eq. (2) Eq. (2) was used for hydraulic conductivity calculation: K ¼ ¼
QL Ah
ð2Þ
where K is the hydraulic conductivity, Q is the flow rate of water, L is the length of the sample (here 15 cm), A is the cross sectional area of the sample (here 46 cm 2), and h is the water head difference of the in-flow and out-flow (here 26–31 cm). 3.3.3. F–T durability test The F–T test was conducted according to the ASTM C666-03. Procedure A, rapid F–T in water, was followed. At the beginning of each test, specimens were either partially or fully submerged in water. The specimens were regularly taken out of the F–T test table in a thawed condition and, after having been dried in the laboratory environment, tested in fundamental transverse frequency. The specimens were then returned to the steel holder to positions according to predetermined rotation schedule. Specimens were removed once they had been subjected to 300 cycles or their relative dynamic modulus of elasticity (RDME) dropped below 60% of the initial value. The RDME was calculated as follows: P c c ¼
n c 2 100 n2
ð3Þ
where P c c is the relative dynamic modulus of elasticity (RDME) after c F–T F–T cycles, n is the fundamental transverse frequency at 0 F–T cycles and nc is the fundamental transverse frequency after c F–T cycles.
Fig. 10. Stress versus strain curve for NSM-2.5-1.19 and UHPM-2.5-1.19.
4. Results and discussion 4.1. Compressive strength of pervious concrete Bond streng Bond strength th betwee between n the aggreg aggregate atess is indire indirectl ctly y evalu evaluate ated d by the mechanical performance of the pervious concrete specimens under uniaxial compression. The compressive strength of conventiona tionall pervio pervious us concre concrete te (PC) (PC) is usu usuall ally y lower lower than than 20 MPa. MPa. Differen Differentt strategies strategies (Fig. 9) 9) have been employed employed by rese researche archers rs aiming at improving the strength of pervious concrete. These pervious vious concretes concretes with enhanced enhanced compressive compressive strength strength are desigdesignated as high strength pervious concrete (HSPC) in this research. Compressive strength over 20 MPa was reported by reducing the A/B ratio ratio [20,21]. [20,21]. Com Compre pressi ssive ve streng strength th of pervio pervious us concre concrete te exceeding 40 MPa was achieved through the incorporation of supplementary cementitious materials (SCMs) such as silica fume (SF) and fly ash (FA), polymer modification of the matrix or combination of SF and fine sand [22–24] [22–24].. It is worth noting that pervious concre concrete te with with compre compressi ssive ve stren strength gth mor more e than than 50 MPa was reported reported in literature, literature, however, however, a 2 MPa mold pressure pressure was applied applied during during testin testing g and the compre compressi ssive ve stren strength gth was reduce reduced d to 27 MPa when the mold pressure decreased to 1 MPa [25] [25]..
Fig. 9. Compressive strength versus total porosity (See (See above-mentioned references for further information). information).
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Fig. 12. Elastic modulus of HPPC and PC.
Fig. 11. Peak strain versus compressive strength.
In this rese research arch high performan performance ce pervious pervious concrete (HPPC) with compressive strength over 40 MPa was designed (Fig. ( Fig. 9) 9) following the aforementioned principles: optimized ultra-high performance formance matrix, enhanced enhanced ITZ, balanced A/B ratio and tailored tailored aggreg aggregate ate size. size. Influe Influence nce of matrix matrix strengt strength h on compre compressi ssive ve strength versus porosity performance of pervious concrete is summarized in [19] in [19]..
4.2. Mechanical properties of pervious concrete under uniaxial compression Fig. 10 compares 10 compares the typical stress versus strain relationship for HPPC and PC. Due to the large pore volume and random nature of the pore size and its distribution, variation in compressive strength and strain at peak stress is typically more pronounced for pervious concrete than for conventional impervious concrete. Equal arc segment curve averaging method [28] method [28] was was used to generate the average stress versus strain curve. Fig. 10 shows 10 shows that both the ascending and descending part of the stress versus strain curve for HPPC is significantly steeper than for PC. This This indica indicates tes higher higher modulu moduluss of elasti elasticit city y and and energ energy y absorption capacity of HPPC than PC. The strain at peak stress for different mixtures is illustrated in Fig. 11. 11. It was observed that the strain at peak stress is comparable for HPPC and PC and both are close to the lower limit (0.002) of conventional concrete [29] concrete [29].. The test results of elastic modulus, strain at peak peak stress stress,, energ energy y absorp absorptio tion n capaci capacity ty and linear linearity ity are
Fig. 13. Energy absorption capacity of HPPC & PC.
presented in Tab Table le 5. Each data data represe represents nts an averag average e of three three meameasurements. Standard deviation of linearity is within 5%. Modulus of elasticity and energy absorption capacity are plotted ted agai agains nstt the the squa square re root root of comp compre ress ssiv ive e stre streng ngth th in Figs. 12 and 12 and 13 13,, respectively. An increase in compressive strength increases the modulus of elasticity and energy absorption capacity.
Table 5
Summary of test results for different mixtures. Series
Mixture
/t (%)
f c c (MPa)
e ( 103)
E t t (MPa)
g (kJ/m (kJ/m3 )
k
HPPC
UHPM-2.5-1.19 UHPM-3.0-1.19 UHPM-3.5-1.19 UHPM-2.5-4.75 UHPM-3.5-4.75
19.8 24.7 29.2 22.5 30.2
65.8 52.9 42.3 34.9 14.6
1.85 1.65 1.48 1.78 1.14
41,300 36,400 39,700 33,000 26,100
70.0 47.4 38.2 39.5 16.0
1.16 1.14 1.39 1.68 2.03
NSM-2.5-1.19 NSM-3.0-1.19 NSM-3.5-1.19 NSM-2.5-4.75 NSM-3.0-4.75 NSM-3.5-4.75
17.0 27.1 30.9 23.4 28.6 30.2
23.2 12.4 8.4 16.0 10.5 8.8
2.08 1.86 1.68 2.18 1.80 1.44
22,300 22,000 16,300 17,000 16,200 19,500
34.2 18.0 11.1 26.9 15.6 12.4
2.01 3.30 3.28 2.31 2.79 3.20
PC
0
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Table 6
Hydraulic conductivity and porosity of HPPC and PC. S er er ia ia l No .
M ix ixt ur ur e No .
/e (%)
/t (%)
K (mm/s)
HPPC
UHSM-2.5-1.19 UHSM-3.0-1.19 UHSM-3.5-1.19 UHSM-2.5-4.75 UHSM-3.0-4.75 UHSM-3.5-4.75
9.5 15.7 20.6 14.0 23.6 26.7
19.84 24.65 29.18 22.46 26.97 30.22
0.25 1.21 1.99 0.52 4.10 5.15
PC
NSM-2.5-1.19 NSM-3.0-1.19 NSM-3.5-1.19 NSM-2.5-4.75 NSM-3.0-4.75 NSM-3.5-4.75
13.6 23.9 29.1 20.5 25.9 28.3
17.02 27.06 30.94 23.35 28.59 30.18
0.41 4.00 6.00 3.60 5.40 6.40
Fig. 14. Linearity versus compressive strength.
Fig. 16. Balanced design of HPPC.
Fig. 15. Correlation between porosity and hydraulic conductivity.
Through Through linear linear best fit, similar similar relations relationship hip [30] between between the square square roo roott of compre compressi ssive ve streng strength th and and elasti elasticc modulu moduluss is ffiffiffiffi observed for pervious concrete (E (E c c ¼ 4880 f c þ 2800) in compar ffiffiffiffi ison to conventional concrete (E (E c c ¼ 4734 f c ). It is worth noting noting
q q
0
0
that the relationship does not intend to predict elastic modulus of elasticity for pervious concrete due to the limited amount of data, but to indicate the trend between pervious concrete and conventional concrete. The linearity k for different mixtures of pervious ous conc concre rete te is summ summar ariz ized ed in Fig. Fig. 14 and and foll follow owss the the 0:53
0
relationship of k ¼ 10 f c . Similar Similar to conventional concrete, pervious vious concrete concrete behaves behaves more linearly, linearly, thus decreasin decreasing g k, with with increased matrix strength. While k of HPPC ranges between 1.1 and 2, the linearity of normal strength PC ranges between 2 and 3.3 (Table (Table 5). 5). 4.3. Hydraulic conductivity Hydraulic conductivity K K is the key property for the practical application of pervious concrete. It is mainly dependent on the
porosity and pore size distribution of the connected pore system. Fig. 15 demonstrates 15 demonstrates the correlation between porosity and hydraulic conductivity for the investigated series. Test results of hydraulic conductivity (based on Eq. (2) (2))) and porosity of HPPC and PC are summarized in Table in Table 6. 6. It is necessary to distinguish between total porosity and effective porosity. While total porosity is an influential parameter controlling compressive strength [19], [19], effect effective ive porosity porosity is use used d to correlate correlate to hydraulic hydraulic conductivi conductivity. ty. Effective Effective porosity porosity is defined defined by the ratio of connected pore volume to the entire volume of the material. Further enhancement enhancement in predicting predicting the hydraulic hydraulic conductivity of pervious concrete can be achieved by considering variations in the structure of the pore system, such as pore size, pore size distribution and connectivity [31] connectivity [31].. In this research a correlation factor of R R 2 = 0.87 was calculated between between hydrauli hydraulicc conductivi conductivity ty and effective effective porosity, porosity, whereas whereas the correlation to total porosity was R was R 2 = 0.67 and therefore lower (Fig. 15). 15). The dependence dependence of of compressive strength on total porosity is plotted in Fig. 16. 16. With the increase of porosity, compressive strength decreases whereas the hydraulic conductivity increases. Compress Compressive ive strength strength and hydraulic hydraulic conductivi conductivity ty are competing competing parame parameter ters. s. It can be seen seen that that all of the PC series series possesse possessed d hydraulic hydraulic conductivit conductivity y over 1 mm/s, mm/s, which is a threshold threshold value for pervious concrete [31,32] concrete [31,32].. However, this satisfactory hydraulic conductivity is achieved at the cost of compressive strength, as indica indicated ted by the lower lower than than or close close to 20 MPa compre compressi ssive ve strength of PC series. Increasing matrix strength while maintaining pore pore volume volume and pore pore struct structure ure allows allows an increa increase se the bond
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Fig. 17. F–T resistance of matrices.
Fig. 19. F–T resistance of pervious concrete.
(a) NSM-3.0-1.19-F
(a) NSM-F
(b) UHPM-3.0-1.19-F
(b) UHSM-F Fig. 18. Matrices subjected to 45 F–T cycles.
streng strength th betwee between n the aggre aggregat gates, es, and thus thus the compre compressi ssive ve strength of pervious concrete, all without sacrificing sacrificing hydraulic conductivity. Here, all HPPC series demonstrated increased compressive strength while maintaining maintaining a hydraulic hydraulic conductivity conductivity over 1 mm/s. It is worth noting noting that pervious pervious concrete concrete with compressi compressive ve streng strength th in excess excess of 50 MPa and with with hydrau hydraulic lic conduc conductiv tivity ity higher than 1 mm/s is achievable (HPPC UHPM-3.0-1.19). 4.4. Durability Pervious concrete has demonstrated excellent performance in the Southeastern U.S., but has seen limited use in environments with with signifi significan cantt freeze freeze–th –thaw aw cycles cycles,, suc such h as Can Canada ada and and the Northern United States [32–34]. [32–34]. Using durable UHPM matrix to cover and bind the aggregates aims at significantly improved durability. Fig. bility. Fig. 17 illustrates the F–T test results for the two matrices under half (H) and full (F) saturation conditions. The NSM-F specimens served as reference values and disintegrated grated severely after 30 F–T cycles as shown in Fig. in Fig. 18a 18a while the UHPM-F specimens remained intact (Fig. ( Fig. 18b). 18b). It should be noted that that no matr matrix ix spec specim imen enss incl includ uded ed any any air air entr entrai ainm nmen ent. t. Furthermore, it has been observed that the deterioration rate of parti partial ally ly subm submer erge ged d spec specim imen enss is lowe lowerr than than that that of full fully y
Fig. 20. Damage comparison of pervious concrete subjected to 90 F–T cycles.
submerged specimens. The influence of the test condition on the same sam e matrix matrix is mor more e pronou pronounce nced d for NSM than UHPM UHPM series series,, which might be attributed to the lower permeability of UHPM. The improved F–T durability of UHPM series in comparison to NSM series can be explained by (1) denser and finer microstructure, and (2) lower amount of freezable water. Due to the incorporation of MPEG type PCE based HRWR and optimized powder size distribution, a better particle packing and distribution of these fine particles for UHPM series can be achieved which ultimately result in a denser microstructure. This is confirmed firmed by the larger larger spread spread value at lower lower w/c ratio c ratio (340 mm) [19].. Furthermor [19] Furthermore, e, the direct direct consumptio consumption n of portlandit portlandite e and formation of additional C–S–H gel due to pozzolanic reaction of silica fume (SF) in UHPM series refines the pore system in the matrix leading to a finer microstructure. The denser and finer microstructure of UHPM series leads to a reduced pore to pore distance and a lower lower possib possibili ility ty of F–T failur failure e based based on Power’ Power’ss hydrau hydraulic lic pressu pressure re theory [35] theory [35].. Additionally, enhanced F–T performance can be partially attributed to the difference in w in w//c ratio ratio of matrix. The w The w//c ratio ratio of UHPM series (0.22) is significantly lower than that of NSM series (0.55). Therefore the amount of freezable water is much less for UHPM series than that of NSM. Fig. 19 summarizes the F–T testing results for pervious concrete. In general, HPPC series demonstrated better F–T durability
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than PC series. This may be explained by (1) better durability performance of UHPM in comparison to NSM, (2) improved interface transition zone (ITZ) and thus improved bond strength between aggregate and matrix. It is observ observed ed that that partia partially lly submer submerged ged specim specimen enss outper outper-formed fully submerged specimens for both HPPC and PC. A similar trend was reported by Guthrie et al. [36] [36].. It should be noted that the difference is more pronounced at higher F–T cycles (after 90 F–T cycles) cycles),, which could be asso associate ciated d to increased increased crack format formation ion and thus larger permeability. Fig. permeability. Fig. 20 compares 20 compares the damage of specimens subjected to 90 F–T cycles. No visible damage was seen for UHPM-3.0-1.19-F specimen whereas the NSM-3.0-1.19-F specimen was severely damaged. It is worth pointing out that the designed HPPC in this research can survive 210 F–T cycles under fully submerged merged test condition condition which outperform outperformss those developed developed by Guthrie et al. [36] al. [36] with air entrainment. In addition, research has shown that incorporation of appropriate amount of fiber reinforcement could further improve the F–T durability of pervious pervious concrete [37].. [37]
5. Conclusions Based on the experimental study and the parameters investigated in this research, the following conclusions can be drawn: 1. Use of optimized ultra-high performance performance matrix (UHPM) along along with with balan balanced ced aggreg aggregate ate to binder binder ratio ratio (A/B) (A/B) and tailor tailored ed aggregate size could potentially advance and broaden the application cation of pervious pervious concrete concrete without sacrificing sacrificing its hydraulic hydraulic conductivi conductivity, ty, leading leading to high performanc performance e pervious pervious concrete concrete (HPPC). 2. HPPC shows higher modulus modulus of elasticity, higher energy energy absorption capacity and increased linearity behavior under compression in comparison to conventional pervious concrete (PC). 3. The relationship relationship between between elastic elastic modulus and square square root of compressive strength of HPPC and PC is similar to impervious concrete. 4. Pervio Pervious us concre concrete te with with a compre compressi ssive ve streng strength th excee exceedin ding g 50 MPa, hydraulic conductivity in excess of 1 mm/s and acceptable F–T durability can be achieved when properly designed. 5. HPPC possesses significantly significantly better F–T durability than convenconventional pervious concrete. It is able to survive 300 accelerated F– T cycles and thus shows the potential to be used under aggressive environment such as northern areas where cyclic freezing and thawing is not uncommon. 6. The F–T durabili durability ty of HPPC HPPC can be expla explaine ined d by (1) denser denser matrix microstructure, and (2) lower amount of freezable water in the matrix. Despite Despite the advantage advantage of improved improved mechanic mechanical al performan performance ce and enhanced enhanced durability durability properties properties of HPPC, HPPC, further further rese research arch is needed to address concerns such as potential shrinkage cracking and higher material cost prior to the application of this material.
Acknowledgements Acknowledgements This research has been supported by a fellowship from the State Scholarship Fund of China, the China Scholarship Council (CSC), and the University of Connecticut. The authors express their great gratitude for the support. Special thanks are also due to L. Zhang, J. Ren, W. Zhong and Y. Li for their valuable assistance with the scanning electron microscope. Additionally, the authors would also like to acknowledge the support from the following companies: Elkem Materials and Lehigh White Cement Company.
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References [1] United United Nation Nations, s, World World Urbani Urbanizat zation ion Prospe Prospects cts – The 2014 2014 Revisi Revision, on, Departmen Departmentt of Economic and Social Social Affairs, Affairs, 2014, 32 p., ISBN 978-92-1978-92-1151517-6. [2] American Concrete Institute, Concrete Technology, Technology, ACI CT-13, p. 78, 2013. [3] United United States States Enviro Environme nmenta ntall Protec Protectio tion n Agency Agency,, EPA, EPA, Storm Storm Water Water Technology Technology Fact Sheet: Sheet: Porous Porous Pavement, Pavement, 832-F-99-02 832-F-99-023, 3, September September 1999, 6 p. [4] L. Haselbach, M. Boyer, J.T. Kevern, V.R. Schaefer, Cyclic heat island impacts on traditional versus pervious concrete pavement systems, J. Transp. Res. Board 2240 (2011) 107–115. 107–115. [5] G. Grant, L. Engleback, B. Nicholson, Green Roofs: Their Existing Status and Potential Potential for Conserving Conserving Biodiversity Biodiversity in Urban Areas, Report Number Number 498, English Nature Research Reports, 2003, 61 p. [6] R. Vingarzan, B. Taylor, Trend Analysis of Ground Level Ozone in the Greater Vancouver/F Vancouver/Fraser raser Valley Area of British British Columbia, Columbia, Environment Environment Canada Canada – Aquatic and Atmospheric Sciences Division, 2003. [7] Urban Urban Draina Drainage ge and Flood Flood Contro Controll Distri District ct (UDFCD (UDFCD), ), Pervio Pervious us Concre Concrete te Evaluation Evaluation Materials Investigation, Investigation, Denver, Colorado. Colorado. Project # CT14, 571– 356. Prepared by Thompson Materials Engineers Inc, 2008. [8] K.M. Houle, Houle, Winter Winter Performanc Performance e Assessment Assessment of Permeable Permeable Pavements Pavements – A comparati comparative ve study of porous porous asphalt, asphalt, pervious pervious concrete, concrete, and conventional conventional asphalt asphalt in a northern northern climate, climate, M.S. Thesis, Thesis, University University of New Hampshire, Hampshire, September 2008, 142 p. [9] C.J. C.J. Pra Pratt, tt, A.P A.P.. New Newman man,, P.C P.C.. Bon Bond, d, Min Minera erall oil bio bio-de -degra gradat dation ion wit within hin a permeable perm eable pavement: pavement: long term observations, observations, Water Sci. Techn Technol. ol. 39 (2) (1999) 103–109. 103–109. [10] N. Neithalath Neithalath,, Developme Development nt and Characteriz Characterization ation of Acoustically Acoustically Efficient Cementitio Cementitious us Materials, Materials, PhD thesis, thesis, Purdue Purdue University University,, West Lafayette, Lafayette, IN, 2004, 269 pp. [11] [11] J.J. Olek Olek,, W.J. W.J. Weis Weiss, s, N. Neit Neitha hala lath th,, A. Maro Marolf lf,, E. Sell Sell,, W.D. W.D. Thor Thornt nton on,, Development of quiet and durable porous Portland cement concrete paving materials, Final report SQDH 2003–5, Purdue University, September 2003, 172 pp. [12] S. Park, M. Tia, An experimental study on the water-purification properties of porous concrete, Cem. Concr. Res. 34 (2004) 177–184. 177–184. [13] E. E.Z. Z. Be Bean an,, W. W.F. F. Hu Hunt nt,, D. D.A. A. Bi Bide dels lspa pach ch,, A fie field ld su surv rvey ey of pe perm rmea eabl ble e paveme pav ement nt sur surfac face e infi infiltr ltrati ation on rat rates, es, ASC ASCE E J. Irr Irrig. ig. Dra Drain. in. Eng Eng.. 133 (3) (2007) 249–255. 249–255. [14] O. Deo, M. Sumanasooriya, N. Neithalath, Permeability reduction in pervious concretes due to clogging: experiments and modeling, ASCE J. Mater. Civil Eng. 22 (7) (2010) 741–751. 741–751. [15]
html > – December 2014. [16] V.R. Schaefer, J.T. Kevern, An Integrated Study of Pervious Concrete Mixture Design Design for Wearing Wearing Course, Course, Final Report – DTFH61-06 DTFH61-06-H-00 -H-00011, 011, National Concrete Pavement Technology Center, Iowa State University, October 2011, 158 p. [17] K. Wille, A.E. Naaman, G.J. Parra-Montesinos, Ultra high performance concrete with compressive strength exceeding 150 MPa (22 ksi): A simple way, ACI Mater.. J. 108 (1) (2011) 46–54. Mater 46–54. [18] C. Schröfl, M. Grube Gruber, r, J. Plank Plank,, Prefe Preferentia rentiall adsorp adsorption tion of polyc polycarbox arboxylate ylate superp sup erplas lastic ticize izers rs on cem cement ent and sil silica ica fum fume e in ult ultrara-hig high h per perfor forman mance ce concrete (UHPC), Cem. Concr. Res. 42 (2012) 1401–1408. 1401–1408 . [19] R. Zhong,K. Wille, Wille, Compression Compression response response of normal and high high strength strength pervious pervious concrete. Construction and Building Materials Materials 2015, Conditionally accepted for publication. [20] H. Fujiwara, R. Tomita, T. Okamoto, A. Dozono, A. Obatake, Properties of highstrength porous concrete, ACI Spec. Publ. 179 (1998) 173–188. 173–188. [21] M.A.R. Bhutta, K. Tsurut Tsuruta, a, J. Mirza Mirza,, Evalu Evaluation ation of high-p high-perform erformance ance porous concrete properties, Constr. Build. Mater. 31 (2012) 67–73. 67–73. [22] Y. Chen, K. Wang, X. Wang, W. Zhou, Strength, fracture and fatigue of pervious concrete, Constr. Build. Mater. 42 (2013) 97–104. 97–104. [23] Y. Chen, K. Wang, D. Liang, Mechanical properties of pervious cement concrete, J. Cent. South Univ. 19 (2012) 3329–3334. 3329–3334. [24] C. Lian, Y. Zhuge, S. Beecham, The relationship between porosity and strength for porous concrete, Constr. Build. Mater. 25 (2011) 4294–4298. 4294–4298. [25] J.J. Yang, G. Jiang Jiang,, Expe Experimen rimental tal study on prope properties rties of pervi pervious ous concr concrete ete pavement materials, Cem. Concr. Res. 33 (2003) 381–386. 381–386 . [26] M.S. M.S. Sum Sumana anasoo sooriy riya, a, N. Nei Neitha thalat lath, h, Por Pore e str struct ucture ure fea featur tures es of per pervio vious us concre con cretes tes pro propor portio tioned ned for des desire ired d pro proper pertie tiess and the their ir per perfor forman mance ce prediction, Cement Concr. Compos. 33 (2011) 778–787. 778–787. [27] O. Deo, N. Neith Neithalath alath,, Comp Compressiv ressive e behav behavior ior of pervi pervious ous concretes and a quantification of the influence of random pore structure features, Mater. Sci. Eng., A 528 (2010) 402–412. 402–412. [28] [28] R. Zhong, Zhong, K. Wille, Wille, Equal Equal arc segme segment nt method method for averag averaging ing data plots plots exemplifie exemplified d for averaging stress versus strain strain curves curves of pervious pervious concrete, concrete, ASCE J. Mater. Civil Eng. (2015), (2015), http://dx.doi.org/1 http://dx.doi.org/10.1061/(ASCE)MT.19430.1061/(ASCE)MT.19435533.0001345.. 04015071, published online May 2015. 5533.0001345 [29] M. Sivaraja, S. Kandasamy, Characterization of concrete composites for energy absorption, J. Reinf. Plast. Compos. 27 (2) (2008) 135–144. 135–144. [30] A.W., A.W., Beeby, Beeby, R.S. Narayanan, Narayanan, Building Building Code Requirements Requirements for Structural Structural Concrete Concrete and Commentar Commentary, y, ACI Committee Committee:: 318–2000, 318–2000, American American Concrete Concrete Institute, Farmington Hills, Michigan.
60
R. Zhong, K. Wille / Construction and Building Materials 98 (2015) 51–60
[31] N. Neithalath, J. Weiss, J. Olek, Characterization enhanced porosity concrete using elect electrical rical impedance impedance to pred predict ict acoust acoustic ic and hydra hydraulic ulic perfo performanc rmance, e, Cem. Concr. Res. 36 (2006) 2074–2085. 2074–2085. [32] [32] K. Wang, Wang, V.R. V.R. Schaef Schaefer, er, J.T. J.T. Kevern Kevern,, M.T. M.T. Suleim Suleiman, an, Develo Developm pment ent of mix prop propor orti tion on for for func functi tion onal al and and dura durabl ble e perv pervio ious us conc concre rete te,, NRMC NRMCA A Conc Concre rete te Tech Techno nolo logy gy Foru Forum: m: Focu Focuss on Perv Pervio ious us Conc Concre rete te 2006 2006,, Nashville, Nashville, TN. [33] V. He Hend nder erso son, n, S. S.L. L. Ti Tigh ghe, e, J. No Norr rris is,, Pe Perv rvio ious us co conc ncre rete te pa pave veme ment nt inte in tegr grat ated ed la labo bora rato tory ry an and d fie field ld st stud ud y y,, J . T ra ran sp sp. R es es . B oa oa rd rd 2 11 113 (2009)) 13–21 (2009 13–21..
[34] N. Delatte, Delatte, D. Miller, Miller, M. Mrkajic, Portland cement cement pervious pervious concrete: field performance investigation on parking lot and roadway pavements, Final Final report of the RMC Research and Education 2007, Silver Springs, MD. [35] T.C. Powers, A working hypothesis for further studies of frost resistance, J. Am. Concr. Inst. 16 (4) (1945) 245–272. 245–272. [36] W.S. W.S. Gut Guthri hrie, e, C.B C.B.. DeM DeMill ille, e, D.L D.L.. Egg Eggett ett,, Eff Effect ect of soi soill clo cloggi gging ng and wat water er saturation satur ation on freez freeze–tha e–thaw w durab durability ility of pervi pervious ous concre concrete, te, Transp Transp.. Res. Rec. 2164 (2010) 89–97. 89–97. [37] J.T. Kevern, K. Wang, V.R. Schaefer, Pervious concrete concrete in sever severe e expos exposures, ures, Concr. Int. 30 (7) (2008) 43–49. 43–49.