Tạp chí Khoa học CNXD - Số 2/2005 (131)
Ngày tạo : 15/07/2015
Tạp chí Khoa học CNXD - Số 2/2005 (131)
·
Tác
dụng ức chế ăn mòn cốt thép của chất ức chế canxinitơrít CNCI-01
TS. Phạm Văn Khoan
·
Chế
tạo vữa tự chảy cường độ cao cốt sợi polypropylene siêu mảnh
TS. Trần Bá Việt
·
Xây
dựng ma trận độ cứng động lực và véc tơ tải trọng nút của phần tử dầm chịu uốn
tổng quát
TS. Trần Văn Liên
·
Chuyển
trục công trình lên cao nhờ công nghệ GPS kết hợp với các trị đo mặt đất
TS. Nguyễn Quang Thắng
·
Ảnh
hưởng của silica colloid đến sự phát triển cường độ của vữa từ xi măng poóclăng
TS. Thái Hồng Chương
·
Cường
độ chịu uốn của dầm bê tông ứng lực trước căng sau không bám dính chịu uốn
thuần tuý
PGS.TS. Nguyễn Tiến Chương
·
Phương
pháp xác định nồng độ cực đại Cmax và khoảng cách Xmax từ
nguồn thải đến điểm có nồng độ cực đại
TS. Bùi Sỹ Lý
·
Ứng
dụng phương pháp quy hoạch phi tuyến để tính công trình ngầm liên kết một chiều
với môi trường đàn dẻo
ThS. Cao Chu Quang ; GS.TSKH. Nguyễn Văn Hợi
·
Kiểm
tra mức độ hư hỏng do ăn mòn clorua kết cấu bê tông cốt thép ở vùng biển Nhật Bản
KS. Trần Nam; ThS. Nguyễn Nam Thắng; KS. Toru Yamaji
Reinforcement corrosion inhibition effect of
corrosion inhibitor of calcium nitrite CNCI-01 (pp. 3-7)
Dr. Pham Van Khoan
This paper introduces some research result on the
reinforcement corrosion inhibition effect of corrosion inhibitor of calcium
nitrite CNCI-01 in the cement-extracting water solution containing NaCl. Based
on the result, the selection of CNCI-01 inhibitor dosage to be used in concrete
in accordance with the actual working condition of the structure and the
aggressive rate by chloride present in the surrounding environment can be
oriented.
Production of high strength self-leveling
fibrillated polypropylene fiber reinforced mortar (pp. 8-12)
Dr. Tran Ba Viet
High strength self-leveling mortar is the material widely
applied in the construction industry owing to its preeminent properties such
as: high flexibility, non-segregation, no bleeding, high toughness etc. In this
paper, the author presents research results and the production of high strength
self-leveling fibrillated polypropylene fiber reinforced mortar most of whose
constituent materials are made in the South of Vietnam. Fibrillated
polypropylene fiber is used to improve the accommodation of the mortar in the
condition of hot-humid climate as well as its cracking resistance capacity.
Establishing the dynamic stiffness matrix and
nodal force vector for general bending beam element (pp.13-17)
Dr. Tran Van Lien
Structure analysis has been done on computer with finite
element method. In theory, the dynamic stiffness method is more precise and
more generalized than the finite element method. This article focuses on how to
establish the dynamic stiffness matrix and nodal force vector for general
bending beam element based on the given analytics function of the beam bending
vibration equation’ solution and the transfer matrix method. In particular
cases, the author has already found the results of the familiar finite element
method. This study accomplishment can be used in teaching, doing scientific
researches and making calculations.
Transferring up the vertical construction axis
by use of GPS in combination with on-land measurement (pp. 18-22)
Dr. Nguyen Quang Thang
Based on the analysis and evaluation of the known methods
for transferring up the vertical construction axis of the buildings, the author
of this article recommends to combine GPS and on-land measurements which are to
be processed according to free network adjustment in order to transfer
coordinates of the control points up to the first floor of each projecting
interval in the step- by-step projecting method with the optical projecting
instrument. The recommended method has been proved by experimental
measurements.
Influence of silica colloid on the strength
development of mortar made from Portland cement and sand (pp.23-28)
Dr. Thai Hong Chuong
Silica colloid is a new highly active puzzolanic material.
Influence of silica colloid on strength development of Portland cement mortar
is the focus of this research.
Experimental data indicated that the addition of silica
colloid to Portland cement mortar improves its compressive strength while its
flexural strength is not improved. This effect of silica colloid is similar to
that of silica fume if added to the mortar. High puzzolanic activity of silica
colloid was proved though X-ray diffraction powder pattern analysis.
Flexural strength of unbonded post-tensioned
prestressed concrete beams (pp.29-32)
A/Prof. Dr. Nguyen Tien Chuong
This paper presents the formulae for predicting the flexural
strength of unbonded post-tensioned prestressed concrete beams, which depends
on the distribution of loads acting on the beam. These formulae are different
from that widely applied in some foreign standards for calculating unbonded
post-tensioned prestressed concrete beams in that the assumption of non
in-plane deformation of the beam’s section is taken into account. This received
theoretical research result should be considered to apply to the actual design
if experimentally confirmed.
A method for determining the maximum
concentration Cmax and the distance Xmax from emission
source to the most pollution point (pp.33-38)
Dr. Bui Sy Ly
In Vietnam,
"Gauss model" has been applied to calculate the pollution diffuse
from the high point
emission source. However, the formula used to determine a pollution
concentration on ground C(x,y,0) or follow wind direction C(x,0,0) of Gauss
model is not able to calculate the maximum concentration Cmax and
the distance from the maximum pollution concentration point to the emission
source Xmax directly, so a method to determine the maximum
concentration Cmax and the distance Xmax from emission
source to the most pollution point follow wind direction in Gauss model with
pollution diffuse calculation chart from the high point source is necessary. It
can fill this gap, in order to estimate and predict quickly pollution status on
site.
Application of the nonlinear programming to
computing underground structures with consideration of the one-sided
constraints between the structure and the elastoplastic medium (pp.39-43)
MEng. Cao Chu Quang; Prof. Dr.Sc. Nguyen Van Hoi
This paper presents a method for computation of underground
structures with the one-sided constraints between the structures and the
medium. on the basis of the principle of the strained energy and the condition
of the one-sided constraints, given problem has been derived to a nonlinear
programming one. Then an algorithm for computation of the underground structure
subjected to static loads was built. In the numerical example a real contact
area between the structure and the medium was determined then a computation was
carried out for the system with the elastoplastic one-sided constraints. A
comparison was made between the received result and the result of the problem
with one-sided elastic constraints.
Investigation of deterioration rate due to
chloride induced corrosion of marine reinforced concrete structures in Japan
(pp.44-50)
Eng. Tran Nam, MEng.
Nguyen Nam Thang, Eng.
Toru Yamaji
The inspection, deterioration prediction, evaluation of
deterioration due to chloride attack are important to keep the reinforcement
concrete structures in marine environment durable during the service life. To
show more clear, this investigation was done in Material laboratory, Port and
Airport Research Insitute of Japan. The experimental carried out in real
reinforcement concrete member taken from Hakata port, including the chlorides
distribution in concrete, corrosion of rebars, cracking of concrete. The result
show that this investigation have adequately inspected the deterioration of
reinforcement concrete. The testing method may be ideal for investigation of
the chloride induced deterioration of concrete structures in marine environment.
