Tạp chí KHCNXD

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.

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