Tạp chí KHCN Xây dựng số 1/2007
Ngày tạo : 15/07/2015
Tạp chí KHCN Xây dựng số 1/2007
Viện KHCN Xây dựng-một số công nghệ
chuyển giao áp dụng hiệu quả trong thực tế 2 năm 2005¸ 2006,
PGS.TS. Cao
Duy Tiến, TS. Vũ Thị Ngọc Vân
Xác định nguyên
nhân và đề xuất giải pháp hạn chế nứt ống bê tông dự ứng lực D 2400mm,
GS.TS. Nguyễn Văn Phó,
TS. Nguyễn Đình Xân: KS. Uông Hồng Sơn, ThS. Lê Văn Minh
Phương
pháp tính tổn hao ứng suất trước do từ biến và co ngót của bê tông,
ThS. Hoàng Quang Nhu
Ảnh
hưởng của cốt sợi thép phân tán đến tính chất của bê tông mác cao trong điều
kiện khí hậu nóng ẩm Việt Nam,
ThS. Nguyễn
Thanh Bình, TS. Trần Bá Việt
Nghiên
cứu ảnh hưởng của phụ gia mịn bột đá vôi và tro bay nhiệt điện đến tính chất
của hỗn hợp bê tông bơm,
TS. Nguyễn
Như Quý
Tác
dụng ức chế ăn mòn cốt thép của canxi nitrit tại khe nứt bê tông,
ThS.
Nguyễn Nam Thắng,
TS. Phạm Văn Khoan, TS. Lê Quang Hùng
Phương
pháp dự báo khả năng sạt lở bờ sông theo chỉ tiêu tích hợp các yếu tố điều kiện
kỹ thuật – tự nhiên vùng ven sông,
ThS. Nguyễn
Văn Tá, TSKH. Trần Mạnh Liểu, ThS. Cao Thanh Tùng
Các
vấn đề an toàn môi trường khi xây dựng nhà máy điện nguyên tử (NMĐNT) ở Việt Nam,
ThS. Nguyễn
Sơn Lâm
Công
trình tường chắn đất có cốt trên vùng núi khai thác mỏ,
PGS. TS. Nguyễn Hùng Sơn
ABSTRACT
Institute for Building Science and Technology - Some technologies
transferred and effectively applied in the two years 2005-2006 (pp.3-5)
A/Prof.
Dr. cao
duy tien, Dr.
Vu thi ngoc van
This
paper presents some technologies transferred and effectively applied in the two
years 2005-2006 by the Institute for Building Science and Technology (IBST) in
the following fields: Geotechnical engineering, Concrete and Construction chemical
products, Restoration and conservation of monuments and cultural structures,
Structural engineering and Surveying engineering. By presenting technologies
transferred and effectively applied in the two years 2005-2006 the authors of
the paper would like to seek the cooperation by individuals, organizations that
are interested in the building science and technology field.
Structural
and non-structural measures for prevention against and mitigation of damage
caused by natural disasters (pp. 6-9)
Prof.
Dr. nguyen Van pho, Dr. nguyen dinh xan
This
paper presents the authors’ opinions on the principles for structural and
non-structural measures for prevention against and mitigation of damage caused
by natural disasters, particularly the typhoons. In addition, the authors also
present their initial considerations on specific measures that can be applied
to the construction of building structures in order to overcome the
consequences caused by the typhoon Shansane, which landed in the middle area of
Vietnam on
October 2006.
Determination
of the crack’s cause and proposing measures for limiting cracks in prestressed
RC pipes with a diameter of D2400mm (pp.10-15)
Eng. Uong Hong Son, MEng.
Le Van Minh
This
paper presents an analysis by the authors to determine the crack’s cause that
happned toprestressed RC pipes with a diameter of D2400mm. Potential causes are
analyzed and investigated, such as: concrete quality of the pipe’s core, the
transportation and installation, influence by environmental temperature, deformation
due to prestress and shrinkage of concrete. In the end, according to the
author, the cause of cracks is concrete shrinkage and a measure for limiting
cracks in prestressed RC pipes with a diameter of D2400mm wasproposed.
Estimating prestress loss of prestressed concrete structures due to
creep and shrinkage (pp.16-21)
MEng. hoang quang nhu
The time-dependent losses of
concrete creep and shrinkage are all of significant importance in prestressed
concrete structures. Effective determination of long-term prestress lose ss is
an integral part of the design of prestressed concrete structures. An
over-prediction in prestress loss results in an overly conservative design for
serviceloads, while an under-prediction in prestress losses could result in significant
cracking at service loads. A precise determination of stress losses in
prestressed concrete members is a complicated problem because the rate of loss
due to one factor, such as relaxation of tendons, is continually being altered
by changes in stress due to other factors, such as creep of concrete. This
procedures here presented will provide more accurate results than by previous
methods which gave no consideration to the actual shrinkage and creep
coefficient.
Influence
or discared steel fibers on the properties of high-grade concrete in the
hot-humid climate of Vietnam
(pp.22-29)
MEng.Nguyen thanh Binh, Dr. tran Ba viet
There
have been many studies on steel fiber reinforced concrete in Vietnam
and all over the world. However, though the study on
discared fiber reinforced concrete has been interested in, this study has not
become systematical.
In
this paper, the authors present a study on the influence of discared steel
fibers on the properties of high-grade concretes in the hot-humid climate
condition of Vietnam
such as: plastic shrinkage, anti-cracking due to plastic
shrinkage, the development of concrete strength with the time, drying
shrinkage,.. of steel fiber reinforced concrete, by comparing these properties
with that of non-fiber reinforced concrete with the same grades.
Some
studies into the effect of fine filler ground limestone and fly ash on
properties of pump concrete mix (pp.30-33)
Dr.
Nguyen nhu quy
Compared
to concrete mix transported without using pump, the pumping concrete mix must
have suitable slump and a mortar content within specified range. In additions
the pumping concrete mix is characterized by good slump retention capacity. In
this report the authors used ground limestone powder and fly ash as fine filler
in combination with high range water reducing admixture to upgrade some
properties of pumping concrete. Some conclusions have made on the capacity of
used type of finefiller in reducing slump loss of pumping concrete mix with
time.
Some
research results on the effectiveness of calcium nitrite corrosion inhibitor in
cracked concrete structures (pp.34-37)
MEng.Nguyen Nam
Thang, Dr.Pham Van Khoan, Dr.Le Quang Hung
This
paper presents some research results on the effectiveness of calcium nitrite
corrosion inhibitor (CN) in cracked concrete. Based on the results obtained,
the authorsfound that calcium nitrite can protect reinforcement in cracked
concrete regions from corrosion over a test period of 24 months. To study, the
test specimens (with a concrete cover of63mm) and a crack width less than0.5mm
were exposed to alternating salt-solution and experienced a continuous drying
process.
Method
of evaluation and prediction of riverside erosive ability according to
intergrative target of factors of technological – natural condition in
riverside area (pp.38-41)
MEng. Nguyen Van Ta, Dr. Sc.tran manh lieu, MEng. Cao Thanh Tung
Based
on analysis of cause, condition and mechanism of riverside erosion, some
factors of technological – natural condition are chosen as: unhomogeneityt of
geological structure (Eđc),material composition (Cd),carve durability (C),
terrain segment high (DH), riverside dip angle (tga;), underground water level fluctuation (Dh), yearly crest of a flood (H), direction of current effect on
riverside (y).
This
paper introduces method of density quantitative evaluation of each factor
above-mentioned and integrate them into quantitative target for evaluation of
riverside erosive ability. The method was used for evaluating the Red riverside
erosive ability in Hanoi area.
The
environmental safety matter when constructing Nuclear power plants in Vietnam
(pp.42-48)
MEng. nguyen son lam
Nuclear
power plants have a superiority over other kinds of power plants such as: high
ouput, occupied land is less than the ussually required,.. However, there is an
inherent problem with Nuclear power plants: the treatment of discharged wastes
and radioactive leakage. The problem might cause serious environmental impacts.
This paper presents the required of aspects of environmental safety matter that
should be observed when constructing and operating Nuclear power plants in
Vietnam including: environmental aspects, environmental impact assessment
caused by Nuclear power plants and some environmental strategies and specific
measures for ensuring the environmental safety.
Reinforced
retaining wall in areas of mining subsidence (pp.49-53)
Prof.
Dr. Nguyen hung son
In this paper, the author presents some research
results on reinforced retaining wall in areas of mining subsidence. With the
help of Plaxis software, the author has simulated the forced deformation of the
ground as a gradual subsidence below the construction during the exploitation
process. The calculation showed the inclination of wall’s surface inrelation to
horizontal ground strain. In addition, variations of extreme axial force in
layers of reinforcement during calculation are also presented in the paper.
