Issue 35

L. Chunjiang et alii, Frattura ed Integrità Strutturale, 35 (2016) 500-508; DOI: 10.3221/IGF-ESIS.35.56

Size of specimen (1×h×t/mm) 150×150×150 150×150×150 150×150×150 300×300×150 400×400×150 500×500×150 150×150×150 150×150×150 150×150×150 300×300×150 400×400×150 500×500×150

Serial number

Crack depth ratio

Depth of cracks [mm]

Thickness of cracks [mm]

Categories

Quantity

RCC1504 RCC1504 RCC1504 RCC1504 RCC1504 RCC1504

12

0.4 0.5 0.6 0.4 0.4 0.4 0.4 0.5 0.6 0.4 0.4 0.4

60 75 90

3 3 3 3 3 3 3 3 3 3 3 3

6 6 6 6 6 9 6 6 9 9 9

RCC

120 160 200

PC1504 PC1504 PC1504 PC1504 PC1504 PC1504

60 75 90

Common concrete

120 160 200

Table 2 : Working conditions of specimen.

Testing Devices Testing devices are shown in Fig. 2.

Top board

Load sensor

Wedge holder

Data acquisit

Signal amplifier

ion system Computer

Clip-on extensometer

Figure 2 : Acquisition of test data with wedge splitting method

Test Results Specimen over 150×150×150 mm 3 is calculated with following formula, and specimen (150×l50×l50 mm 3 ) uses regular computing method [9-11]. Unilateral opening specimen is affected by axial tension, and stress intensity factor (SIF) can be calculated with formula below:   1 / L K af a D    (1)

 h P D t    and   /



















2

3

4

/ 1.122 0.231 / 10.55 / a D a D    f a D





a D

a D

where,

21.71 /

30.382 /

502