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Tubular-type torsion beam rear-suspension systems are widely used in small passenger cars owing to their compactness, light weight, and cost efficiency. It is already known that the roll behaviour of a torsion beam suspension system can be approximated to that of a semitrailing arm suspension system. By this kinematic assumption, analytical equations to obtain the roll centre height, roll steer, and roll camber have already been developed in terms of geometry points. Therefore, this paper proposes an analytical method to calculate the torsional stiffness of a tubular beam from its cross-section area based on the assumption that a tubular beam is a series connection of finite lengths with a constant cross-section. In addition, a potential energy method is proposed to calculate the roll stiffness of a tubular torsion beam suspension system based on considering the bushing stiffness and torsional stiffness of the tubular beam without the use of any commercial computer-aided engineering (CAE) software. The torsional stiffness and roll stiffness predicted using the proposed method showed errors of about 4 per cent and 3.3 per cent respectively, when compared with results from commercial CAE software.

This study aims to evaluate the physical properties of non-sintering cement (NSC) concrete by adding phosphogypsum (PG) and waste lime (WL) to granulated blast furnace slag (GBFS) as sulfate and alkali activators. The study measured changes in the physical properties of fresh concrete using NSC, and the compressive, flexural and tensile strength of the hardened concrete for 360 days. In the results of the experiment, concrete using NSC was superior to that using Ordinary Portland Cement (OPC) or blast-furnace slag cement (BSC) in terms of fluidity and hydration heat characteristics. In addition, the early strength of concrete using NSC was relatively low at around 85% of the strength of concrete using OPC on day 3, but this was reversed from day 7 and the difference between OPC and BSC grew steadily larger over time until day 360. The strength of concrete using NSC develops continuously because the GBFS component eluting as GBFS is activated by PG and WL, and due to their reaction, ettringite, C-S-H gel, etc. are generated steadily for a long time, and there is no transition zone in the interface between the aggregate and paste because Ca (OH) 2 is hardly generated from the hydration process, and as a result, interfacial adhesion is reinforced with aging.

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In this paper, mechanical and germination characteristics of stabilized dredged soils were investigated to recycle dredged soil in eco-friendly manner such as waterfront construction. Non sintering binder (NSB), which was developed by using interchemical reactions between slag, high-calcium fly ash, alkali activator on the dredged marine clay, was added to dredged soil. Ordinary portland cement was also used for the comparison of two binders. Experimental tests such as flow test and unconfined compressive test were carried out to evaluate characteristics of stabilized dredged soil. Leaching test, pH measure, vegetation germination test were also conducted to consider environmental applicability. The unconfined compressive tests shows that unconfined compressive strength (UCS) also increases with the increase of curing time and mixed ratio. UCS of NSB mixtures were higher than those of OPC mixtures. Germination tests showed that germination and sprouting date are better in NSB mixture than OPC mixture. It can be explained that germination decreased as pH and 7-day strength increased.