Puzzolan additives for roller compacted construction (RCC): According to the survey report, the quality of puzzolan in Quynh Thang quarry (Report 1) of PECC1 is following: There was 20.8 ha mining area with reserves of Mines: 3.357 million tons per 21 hectares on the surveyed area. The quantity of Stone which is suitable with quality and requirements of Puzzolan additives under ASTMC 618 construction RCC standards in Ban Ve Hydropower Project are 336,000 tons.
a. Specification and quality of PG Puzzolan in Quynh Thang quarry under ASTMC 618 standard:
|
No.
|
Component
|
Unit
|
Requirements under ASTM C618
|
Puzzolan Additives in Quynh Thang
|
|
1
|
SiO2 + Al2O3 + Fe2O3
|
%
|
≥ 70
|
74,26 – 75,24
|
|
74,75
|
|
2
|
SO3 content
|
%
|
≤ 4
|
0,05
|
|
3
|
Moisture after grinding
|
%
|
≤ 3
|
1,32
|
|
4
|
The lost amount during heating
|
%
|
≤ 10
|
2,38
|
|
5
|
The rest under filter: 0,045 mm
|
%
|
≤ 34
|
16,75
|
|
6
|
Activated intensity after 7 days
|
%
|
≥ 75
|
80,69
|
|
7
|
Activated intensity after 28 days
|
%
|
≥ 75
|
84,18
|
|
|
|
|
|
|
Specifications and the quality of puzzolan additives in Quynh Thang fully meet industry-standard 14 TCN 105-1999: activated mineral additives were finely ground for concrete and mortar - Classification and technical requirements.
b. Standard of Compression resistance strength and tensile strength:
The Result of using puzzolan additives in Quynh Thang for construction roller compacted concrete dam (RCC) at the Ban Ve Hydropower Project showed that the standard of compressive resistance strength and tensile strength at ages such as: R7, R28, R90 is very good and stabile. The data is in the table below:
|
No.
|
|
Unit
|
Requirements in Ban Ve Hydropower
|
Puzzolan additives in Quynh Thang (Min)
|
|
1
|
The compressive resistance strength in 7 - day age
|
MPa
|
5,4
|
7,5
|
|
2
|
The compressive resistance strength in 28 – day age
|
MPa
|
10,0
|
13,0
|
|
3
|
The compressive resistance strength in 90 - day age
|
MPa
|
15,5
|
17,5
|
|
4
|
The compressive resistance strength in 365 – day age
|
MPa
|
18,0
|
21,0
|
|
5
|
The tensile strength in 90 – day age
|
MPa
|
1,0
|
1,0
|
|
6
|
tensile strength in 365 – day age
|
MPa
|
1,2
|
1,3
|
c. Puzzolan additives for roller compacted construction (RCC) that Song Da Joint Stock Company Truong Son has provided construction:
Vietnam Electricity (EVN) is as an investor of Ban Ve Hydropower works (capacity: 320 MW). They used activated mineral puzzolan additives for construction roller compacted concrete (RCC).
Hua Na Hydropower JSC is as an investor of Hua Na Hydropower works (capacity 180 MW). They used activated mineral puzzolan additives for construction Gravity Concrete Dam (CFR).
Petro Vietnam Power Corporation is as an investor of Hydropower works Dakdrinh (capacity 130 MW).They used activated mineral puzzolan additives for construction roller compacted concrete (RCC). |
