1. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
CHAPTER III: MATERIAL REGULATIONS
I. GENERAL
All meterials for box girder and other items shall be in accordance with the
Specification of Project and shall be taken test sample according to quality controlling
plan. Sample for test and construction shall be supervised and approved by Engineer.
Just only use materials which are approved by Engineer according to Specification
and Quality Controlling Plan.
Materials which not satisfy the above requirement shall be rejected and removed out
from Site.
Approved material source shall be use for the entire Project. For a new source, it is
necessary to take sample and be approved by Engineer in accordance with Specification
if the source has any change.
During placing concrete for continuously voided slab beam segments, all materials
must be enough for mixing and providing not interupted.
II. MATERIALS
1. Reinforcement
a. High strength reinforcement
High strength strand with low relaxation shall be in accordance with ASTM416-99
standard of Grade 270 or equivalent, with the main parameters as follows:
+ Grade 270, low relaxation.
+ Breaking strength: fpu = 1860MPa
+ Yield limit: fpy = 1674 MPa
+ Modulus of elasticity: 195000 MPa
+ Relaxation after 1000h at 20°C ≤ 2,5 %.
Construction regulations:
+ High strength strand shall be not welded.
31

2. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
+ Each coil of cable must have Certificate of Producer. The Certificate shows
relative curve between load and elongation, measured area, elastic mudulus for each
lot.
+ High strength cable lots shall be checked before testing, taken sample to test for
each lot or taken a group sample for every 20T.
+ In any case, jacking force for each strand is not over 0, 80 of minimum ultimate
strength of cable.
+ Jack must be suitable with presstressed tendon about structure and tensioning
force. Jack and gauge shall be checked before using.
b. Non-prestressed reinforcement
The Subcontractor intends to use Viet Y Steel for construction Project.
Non-prestressed reinforcement must be in accordance with Specification of Project:
JISG 3112
SD345
2. Prestressed anchor
Pre-stressed anchor must be conformed to 22TCN 267-2000 Standard and the
following requirements:
+ All anchor devices must have enough capacity to keep prestressed cable with a
stress not less than 95% of ultimate tensile strength of prestressed cable showed on
Certificate of Producer and anchor, cable Test Result.
+ Anchor shall be checked to ensure type as submitted, geometric dimension,
mechanical defect to reject defected anchor.
3. Duct
The corrugated duct must be appropriate, synchronous with type, grade of prestressed
cable and anchor. Duct system shall be airproof, waterproof. Diameter of duct must be
greater at least 6mm than nominal diameter of tendon; cross section area must be greater
2.5 times than tendon area.
The minimum thickness of duct must be in accordance with approved design and
instruction of producer that be agreed by Engineer.
32

3. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
4. Concrete
The girder concrete is B arccording to Specification of Project.
Mix design shall conform to Specifications of Project.
Material regulation is as follows:
a. Cement
Cement is Portland cement corresponding to JIS R5210 or ASTM-C150-98 (TCVN
PCB40, TCVN6260-1997) standard. Expiry date and Manufacturer Certificate shall be
submitted before using. Product lots brought into Site must have full bags, components.
Bagged cement shall be kept in a temporary depot and used on time since the material
has been delivered.
Bulk cement shall be kept in silo corresponding to manufacturer regulations.
b. Fine aggregate: Sand
Fine aggregate using for concrete shall be in accordance with JISA 1102 or equivalent
standard.
Aggregate shall be kept to avoid segregating or contaminating. The centre of depot
must be prevented from moisture excess.
To prevent different-size aggregates from mixing together, make a baffle between
them.
Only use uncontaminated, non-toxic mud, clean fine aggregate. The fineness modulus
must satisfy the Specification of Project as the following:
+ Granular composition (according to JISA 1102 standard):
Sieve number (mm) Percentage passing by weight
10 100
5 90~100
2.5 80~100
1.2 50~90
0.60 25~65
0.30 10~35
0.15 2~10A
33

4. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
The Subcontractor has intention in using Mia Duong, Ha 12 – Bo Trach – Quang
Binh coarse sand for concreting works of Project.
Aggregate shall be checked with the above requirements before constructing.
c. Coarse aggregate: Rock 1x2
Coarse aggregate must respond to JISA 1102 or equivalent.
The Subcontractor intends to use stones Len Cut Tai - Quang Trach - Quang Binh for
concreting works of Project.
Coarse aggregate size is shown in the below table:
Sieve number (mm) Percentage passing by weight
30 100
25 95~100
20 -
15 30~70
10 -
5 0~10
2.5 0~5
d. Water
Water for mixing or curing concrete must be fresh water, uncontaminated with oil,
saline, acid, sugar, vegetable or other toxic materials. Excluding water approved as
potable water by competent authority, others shall be tested and satisfied AASHTO-T26
standard: Water for concrete and mortar. Water/concrete ratio is not over 0.40.
Water sources for constructing continuous box girder casted on scaffolding of Do
Vang Bridge shall be the source using for Sub-structure items of Project.
Check pH value at site before placing concrete or test water sample again if
necessary.
e. Admixture
Admixture shall meet instructions JISA 6204.
34

5. Hanoi – Hochiminh city railway line Do Vang Bridge’s construction
bridges safety improvement project technology of beam casted on
scaffolding
Admixture that boots setting speed, increases mobility or retarding admixture, wetting
admixture, v.v… can be use but must be approved by Engineer before constructing.
Admixture may be one of the following types: SiKa Viscocrete 3000-10 to be in
accordance with real construction requirements at Site.
Admixture not the type as required shall be rejected and removed out of Site. Water
fixed content and admixture shall be put together at mixing plant.
Inspector shall check type, maintenance, and ratio of concrete admixture whether as
required or not.
5. Pumped grout
Grout made from Pooclang cement, water and admixture are accepted by Engineer.
Grout is mixed as follows:
Bleeding rate is not over 3%
Non-shrinkage
Swelling index is not over 10%. But this rate is always smaller than bledding rate after
atomizing up to bleed completely.
Compressive strength of cylinder (50x100mm) of 28 days is not smaller than 20 MPa.
The rate of water/cement is not over than 0.4
The content of Cl is not over 0.3kg/m3
Ecflux time is from 10-15 seconds according to Marsh Cone testing.
35