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Effect of Admixtures on Tensile Behavior of Fiber Reinforced Cementitious Composites

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书 书 书

52

 

2017

       

西

 

 

 

 

 

 

 

JOURNAL OF SOUTHWEST JIAOTONG UNIVERSITY

        Vol. 52  No. 1 Feb. 2017

稿

20140627

:浙

2015C33027

);国

51378456

);浙

LZ13E080001

);浙

2014W06

:王

1974

),男

,副

,博

,研

Email

hlwang@ zju. edu. cn

:孙

1976

),女

,副

,博

,研

Email

selina@ zju. edu. cn

:王

,罗

,彭

,等

西

2017

52

):

6168. WANG Hailong

LUO Yuejing

PENG Guangyu

et al. Effect of admixtures on tensile behavior of fiber reinforced cementitious composites

. Journal of Southwest Jiaotong University

2017

52

):

6168.    

02582724

2017

01006108    DOI

10. 3969 / j. issn. 02582724. 2017. 01. 009

掺合料对纤维增强水泥基材料

拉伸性能的影响

 

 

 

 

1.

,浙

江杭

310058

2.

广

西

,广

西南

530007

3.

,浙

江杭

310006

 

:为

PVA

)纤

,采

、硅

,试

、开

、极

,分

:用

65. 0%

,材

25. 5%

26. 0%

,但

;粉

,使

;用

50. 0%

15. 0%

,使

,变

7. 6%

,使

;在

2. 0%

,粉

、硅

、偏

使

2. 0%

,极

3. 99 MPa

,材

,材

,其

175 μm

,平

115 μm.

:水

;裂

;韧

;掺

;拉

TU528. 58   

Effect of Admixtures on Tensile Behavior of

Fiber Reinforced Cementitious Composites

WANG Hailong

  LUO Yuejing

  PENG Guangyu

  SUN Xiaoyan

  YING Qiming

1. College of Civil Engineering and Architecture

Zhejiang University

Hangzhou 310058

China

2. Guangxi Transportation Research Institute

Nanning 530007

China

3. Zhejiang Provincial Institute of Communications Planning

Design & Research

Hangzhou 310006

China

Abstract

To reduce the material cost and understand the modification effects of admixtures on the

tensile properties of polyvinyl alcohol fiberreinforced engineered cementitious composites

PVA

ECCs

),

PVAECCs were prepared with different mass percentages of silica fume

SF

),

fly ash

FA

and metakaolin

MK

for replacement of cement. Then

tensile tests were carried out to study the

tensile properties of the PVAECCs before and after modification

including the ultimate tensile strain

the initial cracking load

the ultimate tensile strength

and the crack development. Furthermore

the

influence mechanisms of the admixtures were discussed on the basis of the experiment. The results

(2)

西

 

 

 

 

 

 

 

52

show that the initial cracking load and the ultimate tensile strength of the composite modified by 65. 0%

of FA were decreased by 25. 5% and 26. 0%

respectively

but the deformation ability was twofold

enhanced. In addition

fly ash improved the crack width and crack distance in the composite

causing

the multiple cracking phenomenon happened more easily in the FA modified composite. For the

composite admixed with 50. 0% of FA and 15. 0% of SF compound

the crack width decreased

however

the deformation ability was increased by 7. 6% compared to the composite admixed with

65. 0% of FA. When MK was incorporated into the composite

the modified materials had better

deformation abilities. For the composites with the incorporation of FA

SF and MK and a moderate

fiber volume fraction of 2. 0%

an ultimate strain exceeding 2. 0% as well as an ultimate strength of

3. 99 MPa was achieved. In addition

the material exhibited a high ductility and multiple cracking

characteristic. The cracks were controlled well by the material itself

in which the maximum crack

width in saturation state was less than 175 μm and the average crack width was less than 115 μm.

Key words

cementitious composite

crack

toughness

admixture

tensile property

   

、韧

,导

,纤

广

,但

,裂

,且

,如

12

,美

LI

20

90

,即

,将

,设

ECC

,以

34

者在此基础上

,内

ECC

、耐

515

,本

、硅

,试

、极

规律

,并对不同配比下的试验结果进行了对比

1 

   

P. O. 42. 5

,其

GB80761997

;精

80 ~ 140

;硅

,细

1 μm

80%

,物

;粉

;偏高岭土采用

DX80

系列

(密

2. 62 g / cm

),其

PVA

;拌

水采用自来水

,减水剂采用

SP8CN

的高效减

1 

Tab. 1  Physical and chemical properties of silica fume

kg

·

m- 3

) 耐

/ ℃

/ μm

m2

·

kg- 1

200 ~ 250 > 1 600 0. 15 ~ 0. 20 1 500 ~ 2 000

2 

Tab. 2  Physical and chemical properties of fly ash

目 细

45 μm

/ %

/ %

/ %

/ %

/ %

/ %

·

cm- 3

8. 0 1. 42 89. 0 0. 27 0. 2 0. 3 2. 6

   

,均

0. 3

,采

、硅

,对

(3)

,等

:掺

,搅

PVA

量(

)约

2%

,详

3 

Tab. 3  Physical and chemical properties of metakaolin %

SiO2 Al2O3 Fe2O3 TiO2 CaO2 K2O Na2O

622 452 0. 5 1. 5 0. 2 0. 5 0. 2

   

试件尺寸为

400 mm × 100 mm × 15 mm

,每组

,均

,试

24 h

,放

28 d

,养

,进

4  PVA

Tab. 4  Properties of PVA fiber

mm

/ μm

/ MPa

/ %

/ GPa

·

cm- 3

12 39 1620 7 42. 8 1. 3

5 

Tab. 5  Mixture ratios of PVA fiber reinforced cementitious composites

号 水

kg

·

m- 3

kg

·

m- 3

kg

·

m- 3

kg

·

m- 3

kg

·

m- 3

kg

·

m- 3

PVA

/ kg C0 1 233 370 617 0 0 0 0. 00 CC1 1 233 370 617 0 0 0 26. 0 CC2 432 370 617 801 0 0 27. 2 CC3 432 370 617 617 185 0 27. 5 CC4 432 370 617 678 62 62 27. 3 CC5 432 370 617 617 62 124 27. 3 CC6 432 370 863 617 62 124 29. 7

2 

   

,使

,并

± 0. 02 mm

24 h

使

,使

100 mm

,最

70 mm

,使

(如

AB

)粘

,将

,固

线

,安

25kNMTS810

,采

测量荷载值

,利用

LVDT

200 mm

IMC

,由

面面积的比值计算抗拉强度

,采用

DJCK

仪观测整个试验过程及峰值荷载

,试

0. 1 mm / min

,直

,试

1 

Fig. 1  Setup for direct tension test

3 

3. 1 

线

   

线

)和

)所

)和

)可

,经

、硅

PVA

线

)弹

线

,在

,基

,其

(4)

西

 

 

 

 

 

 

 

52

,在

)应

,应

,曲

线

,但

,此

,这

,因

,并

16

,此

C0

CC1CC6

2 

线

Fig. 2  Stressstrain relationships of materials under tension

   

)应

薄弱处的裂缝开始张开

,宽度明显增

,应

,出

,经

、硅

、偏

PVA

,随

,最

3. 2 

   

)和

)应

线

、极

(与

,可

ε

,计

,其

w = εL / n

  l = L / n.

,实

,所

、极

,每

,试

C0

,如

)所

,掺

2%

,对

CC4

CC5

,当

,荷

,随

,随

的不断增长

,试件中相继出现多条裂缝

,试件

CC4

CC5

,板

,最

,如

)所

. CC3

CC6

线

,但

,即

使

,仍

,影

6 

Tab. 6  Experimental results of materials under direct tension

Vf/ % S / B σft/ MPa σfu/ MPa εcu/ % l / mm wmax/ μm w / μm C0 0 0. 3 3. 46 3. 46 CC1 2. 0 0. 3 3. 69 4. 31 0. 33 60. 0 190. 0 165. 0 CC2 2. 0 0. 3 2. 75 3. 19 0. 66 12. 5 140. 0 80. 3 CC3 2. 0 0. 3 3. 03 3. 89 0. 71 11. 1 175. 0 78. 0 CC4 2. 0 0. 3 2. 70 4. 01 0. 97 6. 9 167. 0 66. 9 CC5 2. 0 0. 3 2. 36 3. 99 2. 04 5. 6 170. 0 113. 3 CC6 2. 0 0. 3 2. 17 3. 07 0. 22 23. 1 170. 0 82. 6        

S / B

σft

σfu

εcu

wmax

(5)

,等

:掺

C0

CC4

3 

Fig. 3  Cracks'distribution in specimen subjected to tensile load

   

CC3

使

CC6

使

,成

,缺

,导

1718

应变曲线和试件的破坏形态说明

,添加

PVA

、硅

,能

CC5

2. 04%

,极

3. 99 MPa

,并

,达

175 μm

,平

115 μm.

24

89

1819

,即

使

PVA

,但

、硅

,在

,随

,极

3. 3 

   

、降

,而

,降

,更

PVA

:与

,掺

65%

CC2

,但

;掺

CC2

CC1

50%

,裂

CC1

20% .

PVA

:纤

PVA

,如

,则

,纤

;如

,则

,不

PVA

,只

PVA

,纤

,由

,会

CC2

,这

,因

PVA

,粉

,降

,使

CC1

CC2

4 

Fig. 4  Microstructures of CC1 and CC2 matrixes

(6)

西

 

 

 

 

 

 

 

52

,使

,不

,还

PVA

使

PVA

,导

PVA

(如

),有

,与

CC1

CC2

线

,无

,多

,试

CC1

CC2

5 

Fig. 5  Pullout and rupture of PVA fibers in the failed specimens

   

,掺

5% ~ 10%

CC4

CC5

,其

、极

CC3

,这

,不

,还

20

,改

,对

使

PVA

,掺

PVA

、增

,例

CC4

CC2

10. 2%

21. 9% .

5%

5%

CC5

,其

CC2

47% .

CC1

,掺

、硅

、偏

CC5

,主

,均

,使

21

,而

,基

(如

),使

,避

,使

、硅

CC1

CC5

6 

Fig. 6  Distribution of calcium hydroxide in the matrixes

参照

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