Papers by Author: Jun Wang

Abstract: Engineering in seawater face materials corrosion such as concrete and steel bars attacked. Corrosion ions such as chlorides and sulphates exist in seawater with high concentration leading to the durability of engineering made by reinforced concrete degradation. The paper analyzed the mechanisms of steel and concrete in seawater corroded by sulphates and chlorides. According to the conditions of seawater environment the suggestions and measures to develop the durability of the reinforced concrete are proposed from the aspects of structure styles, construction requirements and materials etc.

Abstract: In order to study the strength change of high strength concrete shaft lining structure in underground complex environment resisting composite salt damage erosion, C70 high strength concrete test specimens were made and composite salt disaster solutions of different concentrations were compounded. The test results show that the coefficient of compressive strength and flexural strength of high strength concrete increase in early corrosion and then decline. The strength of specimen declines more quickly in higher corrosion solution concentration in latter time. The change law of the flexural strength is more complex than the compressive strength. Composite salt disaster solutions have little effect for no damage high strength concrete.

Abstract: Settlement calculation of composite foundation is a hot field in geotechnical engineering research . In the paper with an engineering example, useing the equivalent natural settlement calculation methods and weighted modulus settlement calculation methods to calculate the settlement of composite foundations combined by CFG pile and concrete ramming enlarge pile, which compared with the practical measurement result . The results show that the errors of calculated value of the equivalent natural settlement calculation method were permitted and suitable for calculating composite foundation settlement.

Abstract: During freezing sinking, the displacement and affecting factors of deep alluvium frozen soil wall was a technical problem which need to be resolved. Based on designing frozen soil wall in deep alluvium in thousand metre vertical wall, making use of mathematic simulation software of FLAC after selected ten samples from exceeding 400metres depth as calculation model, which the frozen clay creep parameters with finite transformation considered, the maximum radial displacement was obtained. The factors affecting it such as frozen soil thick, height of deep alluvium, segment height, exposure time and excavated radius were utilized. The mathematic formula was acquired with regression analysis through fifty datas, and detected with in-situ measurement data. The result of two types coincids, which indicates it can provide conducting in designing frozen soil wall under similar geoloical projects.

Abstract: The water-cement ratio and cement content are key factors which reflect the anti-penetration of the concrete. To study the slag cement concrete against sulfate attack, make two types of the slag cement concrete test blocks of which one type has the same concrete content and different water-cement ratio, while the other type has the same water-cement ratio and different concrete contents; then test the concrete test blocks on compressive strength, folding strength and weight changing after dipping them into sulfate solution and drying them for thirty and sixty times .At the same time non-damage ultrasonic test was carried out. The results show the durability of the slag cement concrete is improved with the decrease of water-cement ratio; in concrete design, there is optimum cement content which theslagcement concrete has the best resistance sulfate erosion.

Abstract: Scientific prediction the residual life of existing reinforced concrete elements is an important basis for assessment the structures. The resistance probabilistic density function of reinforced concrete elements was proposed by analyzing the random processes of resistance attenuation of concrete and steel bars. Since the factors of concrete durability damaged and materials deterioration , considered practical conditions of service structures and durability failure criteria of concrete members, a method of calculation the residual life was given, which is verified reasonable through the engineering case.