PSI - Issue 6

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

3

13

Table 1. Details of target prestressed and reinforced concrete slabs.

Drop mass, M (kg)

Drop height, H (mm)

Strength of concrete (N/mm 2 )

Type of specimen

Specimen ID

Reinforced concrete slab Prestressed concrete slab

RC

48

242.85

500

PC

48

242.85

500

4. Results and Discussions

4.1. Impact force response under multiple impacts The impact force response was measured at the contact point of impactor and target slab using a load-cell. The magnitude of peak impact force obtained under the multiple impact experiments has been presented in Fig. 1 and Table 2. The magnitude of initial pulse like waveform was reduced for both PC and RC slabs under repetition of impact due to occurrence of some permanent damage in the slab. The reduction in the impact force could be due to reduced stiffness of the concrete slabs. However, the peak impact force measured for the prestressed concrete slab was higher than that for reinforced concrete slab. Therefore, prestressed concrete slab was found to be more impact resistant than the reinforced concrete slab. Under second repeated drop of the impactor, the prestressed concrete slab (PC2) has shown 56% higher load carrying capacity compared with equivalent reinforced concrete slab, see column f of Table 2.

Fig. 1. Impact force response for (a) reinforced and (b) prestressed concrete slab subjected to multiple impacts.