コンクリートの仕上げおよび養生方法の違いが表層品質に及ぼす影響

18

Article

Effects of Finishing and Curing Methods on Surface Properties of Concrete

Taiga SAKAMOTO

_{, Takehiro SAWAMOTO}

_,

_{Masanori HIGUCHI}

_,

Akiyoshi DAI

_{and Koichi KAJI}

*1

_{Undergraduate, Dept. of Building Technologists, Institute of Technologists}

_{Dept. of Building Technologists, Institute of Technologists}

*3

_{SUMITOMO MITSUI Construction Co.,Ltd}

Abstract In this study, the effects of the difference in finishing methods and curing methods of concrete on the surfaces properties were examined by scratch test, rebound hammer test, surfaces tensile test, air permeability test, water absorption test, and scaling test. As a result, wet curing was effective to improve the surface properties of concrete. When finishing agent was used, concrete surface became denser, and coefficient of air permeability tended to be small. When wet curing was begun from 6 hours after finishing of concrete surface, total amount of scaling was small.

Key Words : Concrete, Finishing, Curing, Air permeability, Water absorption, Scaling, Rebound number

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The Bulletin of Institute of Technologists, No. 8

2.66g/cm

2.60g/cm

2.63g/cm

₃

2.69g/cm

AE

1

40

20

40.4

2

19.0cm

5.6%

31.1

0.07

4

4

40

7

45.3N/mm

₂₈

_50.9N/mm

28

47.7N/mm

300mm

2

1

3

NN

AN

AA

Fig.1 Compaction Fig.2 Finishing agent

Fig.3 Wet curing Fig.4 Scratch test

Fig.6 Surface tensile test Fig.5 Rebound hammer test

Table 2 Test results of fresh concrete and compressive strength Table 1 Mix proportion of concrete

20

Fig.7 Air permeability test Fig.8 Water absorption test Fig.9 Scaling test

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The Bulletin of Institute of Technologists, No. 8

0 2 4 6 8 -6 -3 0 3 6 9 12 15 18 21 24 Free Finishing agent

Fig.12 Effects of curing methods on tensile strength 0 0.05 0.1 0.15 0.2 0.25 0.3 -6 -3 0 3 6 9 12 15 18 21 24 Free Finishing agent 0 0.05 0.1 0.15 0.2 0.25 0.3 -6 -3 0 3 6 9 12 15 18 21 24 Free Finishing agent

Fig.10 Effects of curing methods on scratch width

(1) Age of 4days (2) Age of a month

15 20 25 30 35 -6 -3 0 3 6 9 12 15 18 21 24 Free Finishing agent 15 20 25 30 35 -6 -3 0 3 6 9 12 15 18 21 24

AA wet curing start timing h Free

Finishing agent

Fig.11 Effects of curing methods on rebound number

(1) Age of 4days _{(2) Age of a month}

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Fig.14 Effects of curing methods on water absorption speed

0 1 2 3 4 5 -6 -3 0 3 6 9 12 15 18 21 24

AA wet curing start timing h Free

Finishing agent

Fig.15 Effects of curing methods on total amount of scaling

0.001 0.01 0.1 1 10 -6 -3 0 3 6 9 12 15 18 21 24 Free Finishing agent 0.001 0.01 0.1 1 10 -6 -3 0 3 6 9 12 15 18 21 24 Free Finishing agent

Fig.13 Effects of curing methods on coefficient of air permeability

(1) Age of 14days (2) Age of a month

11

12

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The Bulletin of Institute of Technologists, No. 8

14

15

15

6

1

4

(1)

(2)

(3)

(4)

6