PSI - Issue 6

Vimal Kumar et al. / Procedia Structural Integrity 6 (2017) 11–18 Author name / Structural Integrity Procedia 00 (2017) 000 – 000

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Fig. 2. Displacement response for (a) reinforced and (b) prestressed concrete slab at the center span under multiple impacts.

Table 4. Peak displacements for PC and RC slabs at the quarter span. Reinforced concrete slab ID Displacement (mm) Prestressed concrete slab ID

Reduction in disp. due to prestressing (%) f=(c-e)/c, (%)

Displacement (mm)

a

b

c

d

e

Fresh slab 1 st repetition

RC0 RC1

6.792 6.650

PC0 PC1

5.026 5.009

26.00 24.68

Fig. 3. Displacement response for (a) reinforced and (b) prestressed concrete slab at the quarter span under multiple impacts.

4.3. Energy absorption capacity The energy absorption capacity of reinforced and prestressed concrete slab has been obtained by calculating area under the load-displacement curve. The prestressed concrete slab has shown higher energy absorption capacity compared with the reinforced concrete slab. Under successive impact, the energy absorption by the slab has increased for both reinforced and prestressed concrete slab compared with the fresh slab specimen. However, it should be noted that the magnitude of the peak impact force has reduced under repeated impacts, see Table 2. Therefore, the increase in the energy absorption under successive impact is primarily due to increase in the displacement of the slab. Although, it should be noted that this increased energy has no importance for the design of the concrete slabs.

Table 5. Energy absorption capacity of slabs under multiple impact Reinforced concrete slab ID Energy absorption (J) Prestressed concrete slab ID

Energy absorption (J)

a

b

c

d

e

Fresh slab 1 st repetition

RC0 RC1

963

PC0 PC1

986

1052

1089