Crack Paths 2009

3. R A WM A T E R I A LASN DM I XP R O P O R T I O N S

Materials：P·MH42.5 moderate heat cement，Class F fly ash，high range water

reducer and air entrainment were used.

Fine aggregate is manmadesand, i.e. sand stonesand and marble sand. Table 1 shows

the properties of fine aggregate.

Table 1 The physical properties of fine aggregate

Specific gravity （ g / m 3 ） WaterAbsorption （ % ）

Type of fine aggr gate

Fmiondeunlesus

Content of stone p o w d e r （ % ）

Sandstone

2.96

16.3

2.74

1.8

2.72

Marble

2.05

25.0

1.5

Coarse aggregate is manmadecrushed sandstone. Table 2 shows specific gravity and

water absorption of coarse aggregate. The content of flaky and elongated particles is

less than 3.6% and the crushing indexis not over 6.3%.

Table 2 The physical properties of coarse aggregate

Specific gravity

Size of aggregate（mm）

Water Absorption（%）

（ g / c m 3 ）

5～20

2.72

0.8

20～40

2.74

0.5

40～80

2.74

0.4

80～150

2.74

0.2

Table 3 shows the mix proportions. Sand ratio and content of chemical admixtures

were adjusted to control the slump in range of 3cm and 5cm.

Table 3 Mixproportions of concrete

Mixproportion（kg/m3）

Type ofaggregate

Coarse aggregate Series Water Cement Falsyh Sand 250 m～m 4200m～m 8400m～m 1850m～m

rWeadutcer

entraAinrment

aggFriengeate Coarse

aggregate

S M 84

155 66 386 421 452 469 419

1.1

0.133

Sandstone

Marble

SS 84

155 66 472 335 452 469 419 1.99

0.176

Sstaoned

Sand

stone

4. R E S U L TAS N DDISCUSSIONS

A 2000mmlong concrete beam of cross section 150mm×150mismcast horizontally.

The measuring system has an initial length of 1500mm.The sensitivity of temperature

sensor is 0.1 ℃ , and that of displacement sensor is 0.1μm. After 120s mixing, the coarse

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