Structural behavior of Reinforced Concrete (RC)

beams using stainless slag as fine aggregates

Presented by Madeira Branco Leandro Yamaguchi University

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Government through to Minister of environment

prohibited extend exploration of sea sand in Seto inland sea

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Research background

Environmental problem due to issue of

discharge industrial waste material

Use stainless slag as an alternative fine aggregate

Study of RC beams containing stainless slag as fine aggregate

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Description RC beams material Table 1. Description of concrete material

Material Density (g/cm3)

Water absorption

(%)FM

 G max (mm)

Stainless slag (NSS) 3.08 1.53 2.95  Sea sand (S) 2.57 1.62 2.85 Ordinary Cement (C) 3.15 -    Crushed gravel (G) 2.70 1.00 20 Water (W) 1.00      AE (Frolich SV) 1 % of total Cement

Table 2. Description of reinforcement

TypeElastic

ModulusYielding strength

Area(mm2) Remark

(kN/mm2) (N/mm2)Ø 6 120 388 63.67 stirrupD 16 200 350 397.2 tendon

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RC description and testing method

P/2 P/2

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Description mix proportion

Table 3. Mix proportion of concrete Type

 W/C

Material (kg/m3) Slump Design

(cm)

Slump

Measured (cm)

Air content Design

(%)

Air content Measured (%)

 W

 C

 NSS

 S

 G

 AE

Slag 0 % 28 days

50 170

340

0 696 1097

3.40

12±2

12

4.5±1.5

3.5

Slag 60 % 28 days

50 170

340

500 278 1097

3.40 10.5 3.8

Slag 0 % 91 days

50 170

340

0 696 1097

3.40 10 3.5

Slag 60 % 91 days

50 170

340

500 278 1097

3.40 10 3.5

Progress of curing, testing and result

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Table 4. Mechanical property of plain concreteSlag (%)

28 days 91 daysf’c

(N/mm2)Ft (N/mm2) E

(kN/mm2)f’c

(N/mm2)Ft (N/mm2) E

(kN/mm2)0 32.3 2.70 37 45.4 3.17 4060 34.3 2.56 40 46.3 3.72 41

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Result of concrete and RC beams strength

Table 5. Ultimate strength of RC beams

Slag

Calculation Experiment

Note

28 day 91 days 28 day 91 days

Mu (kN.m)

Vc (kN)

Vu (kN)

Mu (kN.m)

Vc (kN)

Vu (kN)

P max (kN)

Mu (kN.m)

SF (kN)

Pmax (kN)

Mu (kN.m)

SF (kN)

0% 20.1132.61   20.81 36.56   79.38 19.85 39.69 86.06 21.81 43.03 Without

Stirrup

  53.36     57.31 79.97 19.99 39.98 82.78 20.70 41.39 With Stirrups

60% 20.2633.28   20.84 36.78   86.24 21.56 42.88 - - - Without

Stirrup

  54.03     57.53 87.51 21.88 43.76 88.28 22.07 44.14 With Stirrups

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Crack Pattern at ultimate load Slag (%) W/

C

stirrups 28 days 91 days

0 50 No

0 50 Yes

60 50 No

60 50 Yes

Result of RC beams

With stirrups 9 Without stirrups

Without stirrupsWith stirrups

Result Cont......

With stirrups 10Without stirrups

Ultimate strength of each RC beam using stainless slag shows slightly larger than those without stainless slag at age 28 and 91 days.

RC beams using stainless slag have slightly large level of ductility compared to those without using stainless slag at ultimate load.

Crack pattern of RC beam containing stainless slag is similar to normal RC beams

Stainless slag can be used as fine aggregate in the concrete structure

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Conclusion

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Thank you very much for your attention