Đặc tính cấu trúc rỗng của AAC

1. 5.1 Microstructure of AACs
The microstructure of AACs were studied
through:
- Hydration products;
- Morphology of hydration product;
- Pore size distribution.
1

2. Pore size distribution (MIP)
2
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
1 10 100 1,000 10,000 100,000
dV/dlog(r),
ml/g
Pore radius (r), nm
VN3 VN4
VN6 VN5
JP2 JP1
VN1 VN2

3. Pore size distribution (MIP)
3
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
1 10 100 1,000 10,000 100,000
dV/dlog(r),
ml/g
Pore radius (r), nm
VN3 VN4
VN6 VN5
JP2 JP1
VN1 VN2

4. Pore size distribution (MIP)
4
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
1 10 100 1,000 10,000 100,000
dV/dlog(r),
ml/g
Pore radius (r), nm
VN3 VN4
VN6 VN5
JP2 JP1
VN1 VN2

5. 5
5.2 Length change behavior of AAC
AAC material selection
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
1 10 100 1,000 10,000 100,000
dV/dlog(r),
ml/g
Pore radius (r), nm
VN3 VN4
VN6 VN5
JP2 JP1
VN1 VN2

6. 6
5.2 Length change behavior of AAC
AAC material selection

7. 5.2 Length change behavior of AAC
AAC
Vycor glass (Haines & McIntosh)
7

8. 5.2 Length change behavior of AAC
AAC Cement paste (Feldman & Sereda)
8

9. Effect shrinkage reducing agent on length
change behavior of AAC
9
- The shrinkage reduction is
significant at high RHs condition,
and is negligible at low RHs
condition (below 65% RH);
- The significant shrinkage
reduction in the range of about 65-
95% RH further supports for the
action of capillary tension at high
RHs condition.
𝒒 =
2𝜸
𝑟𝑠
Capillary pressure:
rs: the Kelvin radius where meniscus is formed
γ: the surface tension of solution ( γ of solution
for JP1 and JP1-3 are 71.6 and 36.8 mN/m,
respectively).

10. Comparison the length change behavior of
Vietnamese and Japanese AACs
10
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
1 10 100 1,000 10,000 100,000
dV/dlog(r),
ml/g
Pore radius (r), nm
JP1
VN1
VN2
- No expansion in desorption
process was observed for VN1
and VN2. The shrinkage
hysteresis in VN1 and VN2 is also
significantly less than in JP.
- The higher volume of finer pores
leads to the retention of more
water in AAC at high RH;

11. Comparison the length change behavior of
Vietnamese and Japanese AACs
11
0
20
40
60
80
100
0 0.2 0.4 0.6 0.8 1
Ultimate
water
content,
%
P/Po
Desorption JP2 Desorption VN6
Desorption VN5 Desorption VN3
Desorption VN4 Adsorption JP2
Adsorption VN6 Adsorption VN5
Adsorption VN3 Adsorption VN4
-1200
-1000
-800
-600
-400
-200
0
0 0.2 0.4 0.6 0.8 1
Length
change
strain,
μ
P/Po
Desorption JP2 Desorption VN6
Desorption VN5 Desorption VN3
Desorption VN4 Adsorption JP2
Adsorption VN6 Adsorption VN5
Adsorption VN3 Adsorption VN4