A/Prof. Dr. Cao Duy Tien

This paper highlights the role of IBST in the developing of building standards and codes for the purpose of supporting the Vietnam Ministry of Construction in the State management duty with respect to the Construction Industry and in the approaching International standard system for harmonization. During the last year (2004) IBST has developed 10 of 33 Vietnam building standards (TCXDVN) issued by Vietnam MOC. Another 10 important Vietnam building standards and codes scheduled to be developed in 2005 are also stated, showing the great contribution of IBST to the development of the Vietnam Construction Industry.

A method for determining the compressive stress-strain curves of concrete from flexure tests of specimens having circular cross-sections (pp. 5-9).

Dr. Nguyen Ngoc Ba

This paper presents a new method for determining the compressive stress-strain curves of concrete from flexure tests of plain or reinforced concrete specimens having circular cross-sections. This method is based on the strain compatibility and the force and moment equilibrium conditions established on the critical cross-section of the test specimen. This method is applicable to different kinds of tests such as pure flexure tests, tests of columns under constant end eccentricities, or tests of columns under constant neutral axis depth.

Reliability assessment on local buckling of thin-walled members under axial compression (pp.10-16).

MEng. Do Van Binh, A/Prof. Dr. Le Xuan Huynh

Introduction to remedial methods for non- homogeneous piles using Jet Grouting (pp.17-24)

A/Prof.Dr. Nguyen Viet Trung, Eng. Nguyen Thi Tuyet Trinh

This paper introduces remedial methods for non-homogeneous bored piles using Jet Grouting method, especially Column Jet Grouting with jet grouting machine having the triple pipe. This method is effective, applied for remedial works at some building constructions and bridges in Vietnam. Some results are also presented. Based on the tesing results, the effect of the method and prospect of applying this method in Vietnam is confimed.

The measurement of steel corrosion rate by polarization resistance technique (pp. 25-30)

Eng. Vu The Phuong, Eng. Tran Nam.

A simple method is presented to measurement the corrosion rate of steel rebar in reinforcement concrete and steel beam in field structure. The method is based on the determination of polarization resistance of steel. Measurement were done by using potentiostat Gamry PC4/750 computer controled. The technique investigated furnishes results with good precisely and more rapidly, and the technique has been proven feasible for both reinforcement concrete and steel structure.

Combination treatment system for wastewater and toxic gas discharged at fibro cement roofing tile factories (pp. 31-34)

MEng. Nguyen Son Lam, MEng. Nguyen Trinh Huong

This paper introduces the combination treatment system for wastewater and gas discharged at fibro cement roofing tile production factories. Neutralization of wastewater with high pH value by discharge acid gas occurred in coal ash firing in water boiler is taken place in the absorption tower. After the treatment, wastewater and gas discharged into environment meet Vietnamese emission standards (TCVN). The treatment system is economically feasible and can be applied for most roofing tile production factories in Vietnam.

Standard acceleration response spectrum recommended to be applied to design of earthquake resistance in Vietnam (pp. 35-45.)

Prof. DSc. Nguyen Dang Bich, Dr. Nguyen The De, Prof. Dr. Nguyen Dinh Xuyen and MEng. Pham Dinh Nguyen.

The most important question for the design of earthquake resistance for structures and building constructions in the seismic areas of Vietnam is the establishing the Standard acceleration response spectrum. In this paper, the authors present the way to establish the above response spectrum based on the Vietnam seismic data available. The result obtained is reliable, and to some certain extent it is similar to the Standard acceleration response spectrum in the American standard UBS-1997.

The change of geometric parameters of thermal isolating PU Vietrust exposed to alkaline solution (pp. 46-48).

MEng. Mai Thanh Nga, A/Prof. Dr. Le Xuan Que

Porous polyuethane (PU) is a super-light building material widely used for producing ceiling, cladding, thermal isolating partitions in civil and industrial structures. However, the stability and working life of this material has not been studied yet.

This paper presents the expansion test of a thermal isolating building material, called PU Vietrust, exposed to alkaline solutions of pH up to 12, which is similar to the environment in concrete and mortar. It has been found that after 60 days testing at room temperature without stirring, the maximum expansion of dimension of the sides is of some 5%, while that of the volume is of some 7%.

Eng. Nguyen Ngoc Tinh

When spreading over building structures, there are 3 force components appeared caused by a tornado. one of these components is the inside-to-outside pressure on the structure (if the structure is sealed). This pressure appears because the pressure at the centre of the tornado is very low and the acting duration of the tornado on the building is very short while the initial atmotsphere pressure inside the building is equal to that of the surroundings.