コンクリート柱部材の透気性に及ぼす打込み時期および使用環境の影響に関する研究

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12 Article

*1 *2 *3 *4 *4 *1 *2 *3 *4

A Study on Effects of Placing Seasons and Environments

on Air Permeability of Concrete Pillar Members

Masato SAITO

*1

_{, Takehiro SAWAMOTO}

*2

_{, Koichiro SHITAMA}

*3

_{, Masanori HIGUCHI}

*4

_{and Akiyoshi DAI}

*4

*1

_{INSTITUTE OF TECHNOLOGISTS, Graduate School of Technologists}

*2

_{INSTITUTE OF TECHNOLOGISTS}

*3

_{MAEBASHI INSTITUTE OF TECHNOLOGY}

*4

_{SUMITOMO MITSUI CONSTRUCTION Co.,Ltd.}

Abstract The properties of concrete surface which influence the durability of concrete structures will be greatly

affected on placing seasons and use environments. In this study, the effects of type of cement, placing season and use environment on air permeability of concrete were investigated. As a result, there was no clear correlation between the coefficient of air permeability and the placing season. About the use environment, the coefficient of air permeability of the concrete pillar member under rainy outdoor environment was smaller than that of the pillar member under indoor environment, and it was conspicuous by using the portland-blast furnace slag cement typeB compared with using the normal portland cement.

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13 The Bulletin of Institute of Technologists, No. 9

1 4) 5 9)

B

3.16g/cm

3

_B

3.04g/cm

3

2.61g/cm

3

_2.75

20mm

2.64g/cm

3

_59.0%

AE

Table 1

N

B

BB

27 1200mm

W C S G Ad Slaump_(cm) _(%)Air Temperat_{ure( )} 1day 2days 7days 12days Placing Cement W/C

(%) Slaump

(cm)

Unit content (kg/m Properties of fresh concrete Strength at mold-demolding (N/mm2₎ Strength

under standard

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15 The Bulletin of Institute of Technologists, No. 9

Fig.6

NR

1 JIS

A 1155

9 N

BB

Fig.7

Fig.8

N

BB

N

BB

1

1.0

10

-16

_m

2 1 2)

_0.1

10

-16

_m

2

1 Fig.9

N

BB

0.01 0.10 1.00 10.00 0 50 100 150 200 250 300 350 400 Age (days)

Spring(Outdoor Demolding at ago of 2 days ) Spring period(Outdoor Demolding at ago of 7 days ) Summer(Outdoor Demolding at ago of 1day ) Summer(Outdoor Demolding at ago of 7days ) Winter(Outdoor Demolding at ago of 12 days)

0.01 0.10 1.00 10.00 0 50 100 150 200 250 300 350 400 Age (days)

Spring(Outdoor Demolding at ago of 2 days ) Spring period(Outdoor Demolding at ago of 7 days ) Summer(Outdoor Demolding at ago of 1day ) Summer(Outdoor Demolding at ago of 7days ) Winter(Outdoor Demolding at ago of 12 days)

0.01 0.10 1.00 10.00 0 50 100 150 200 250 300 350 400 Age(days)

Spring(Outdoor Demolding at ago of 2 days ) Spring period(Outdoor Demolding at ago of 7 days ) Summer(Outdoor Demolding at ago of 1day ) Summer(Outdoor Demolding at ago of 7days )

Winter(Outdoor Demolding at ago of 12 days) _0.01

0.10 1.00 10.00

0 50 100 150 200 250 300 350 400

Age (days)

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16 (

)

N

BB

N

BB

10)

N

BB

N

BB

Fig.10

N

BB

(1)

(2)

N

BB

N

BB

N

BB

N

BB

(3)

0.001 0.1 10 1000 0 50 100 150 200 250 300 350 400 Age (days)

Spring(Outdoor Demolding at ago of 2 days ) Spring period(Outdoor Demolding at ago of 7 days ) Summer(Outdoor Demolding at ago of 1day ) Summer(Outdoor Demolding at ago of 7days ) Winter(Outdoor Demolding at ago of 12 days) Spring(Indoor Demolding at ago of 2 days ) Spring period(Indoor Demolding at ago of 7 days )

0.001 0.1 10 1000 0 50 100 150 200 250 300 350 400 Age (days)

Spring(Outdoor Demolding at ago of 2 days ) Spring period(Outdoor Demolding at ago of 7 days ) Summer(Outdoor Demolding at ago of 1day ) Summer(Outdoor Demolding at ago of 7days ) Winter(Outdoor Demolding at ago of 12 days) Spring(Indoor Demolding at ago of 2 days ) Spring period(Indoor Demolding at ago of 7 days )

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17 The Bulletin of Institute of Technologists, No. 9

RC

( )

1) N R. J. Torrent A two-chamber vacuum cell for