r - The Hong Kong Polytechnic University

Concrete
PDCC
(a)
(b)
Figure 3 (a) Transverse grooves on the PDCC, and (b) Crack control ability of the PDCC layer
Specimen Design & Test Setups
The Slab Specimens (SF and SU) were prepared using both flat plate and U-shaped formwork with 3 GFRP bars
inside. The Beam Specimen BF1 and BU1 were designed to have the same Steel/GFRP ratio, but prepared with
flat plate and U-shaped formwork respectively. An additional set of specimens BU2 with U-shape formwork and
a different reinforcement ratio was also prepared. The design details are listed in Table 3. For each specimen
type, 2 beams were prepared and tested.
Table 3 Specimen Details
Type Reinforcement Shape
SF GFRP:3R6 Flat
BF1 GFRP:4R6 Steel:2R10 High Yield Steel Flat
SU GFRP:3R6 U
BU1 GFRP:4R6 Steel:2R10 High Yield Steel U
BU2 GFRP:5R6 Steel:4R8 Mild Steel U
Test setup and reinforcement arrangement details are shown in Figure 4. Four point testing was performed on all
specimens. For the beam specimens, the total span was 1800mm while the mid-span between loading points
was 300mm. For the slab specimens, the total span was 2800mm and the loading points were 200mm apart. In
all tests, the loading rate was set to be 0.5mm/min.
750 300
750
1300 200
1300
@100spacing
@100spacing
GFRP Reinforcement
PDCC Formwork
100
20
150
30 30
250
70
20
80
30 30
150
150 150
100 100
BU1
BF1
SU
Figure 4 Test Setup
SF
RESULTS
Figure 5(a) and 5(b) show the typical load vs displacement behaviours for the various slabs and beams made
with permanent formwork. Both slabs were able to reach the load capacity calculated from conventional
reinforced concrete design. However, for the slab made with flat plate formwork (SF), delamination was
-120-