Buckling Resistance of Axially Restrained Chord Members of Grid Structure at Elevated Temperatures

This paper investigates the behavior of large span grid structure exposed to a localized fire. The localized fire may generate hot smoke and thus induce non-uniform temperature distribution in the grid structure. The thermal expansion of the heated members tend to be axially restrained by the adjacent cold members thus inducing additional forces on the critical members of the grid structure. The buckling resistance of axially restrained member at elevated temperature may be obtained based on second order analysis of member with initial lateral imperfection by considering force equilibrium at deformed geometry and cross section resistance being reached. The critical temperature of the member is reached when the axial force reaches its buckling resistance. It is found that the critical temperature of members with initial lateral imperfection was higher than that without such imperfection for chord members with large slenderness ratio and high axial restraint

Stability of cenospheres in lightweight cement composites in terms of alkali-silica reaction

10.1016/j.cemconres.2012.02.010Cement and Concrete Research425721-72

Behavior of steel-concrete-steel sandwich structures with lightweight cement composite and novel shear connectors

10.1016/j.compstruct.2012.05.023Composite Structures94123500-350

Creep and shrinkage of ultra lightweight cement composite

Creep and shrinkage behaviour of an ultra lightweight cement composite (ULCC) up to 450 days was evaluated in comparison with those of a normal weight aggregate concrete (NWAC) and a lightweight aggregate concrete (LWAC) with similar 28-day compressive strength. The ULCC is characterized by low density < 1500 kg/m3 and high compressive strength about 60 MPa. Autogenous shrinkage increased rapidly in the ULCC at early-age and almost 95% occurred prior to the start of creep test at 28 days. Hence, majority of shrinkage of the ULCC during creep test was drying shrinkage. Total shrinkage of the ULCC during the 450-day creep test was the lowest compared to the NWAC and LWAC. However, corresponding total creep in the ULCC was the highest with high proportion attributed to basic creep (≥ ~90%) and limited drying creep. The high creep of the ULCC is likely due to its low E-modulus. Specific creep of the ULCC was similar to that of the NWAC, but more than 80% higher than the LWAC. Creep coefficient of the ULCC was about 47% lower than that of the NWAC but about 18% higher than that of the LWAC. Among five creep models evaluated which tend to over-estimate the creep coefficient of the ULCC, EC2 model gives acceptable prediction within +25% deviations

Water and chloride ion penetration resistance of high-strength ultra lightweight cement composite

Durability is a significant issue to focus on for newly developed structural lightweight cement composite (ULCC). This paper presents an experimental study to evaluate the resistance of ULCC to water and chloride ion penetration. Chloride penetrability and sorptivity were evaluated for ULCC (unit weight about 1450 kg/m3) and compared with those of a normal weight concrete (NWC), a lightweight aggregate concrete (LWC), and an ultra lightweight composite with proprietary cementitious binder (DB) (unit weight about 1450 kg/m3) at similar compressive strength of about 60 MPa. Rapid chloride penetrability test, rapid migration test, water absorption (sorptivity) test, and water permeability test were conducted on these mixtures. Results indicate that ULCC and DB had comparable performance. Compared with control LWC and NWC at similar strength level, the ULCC and DB mixtures had higher resistance to chloride ion penetration, lower water absorption and virtually impermeable to water penetration

Novel steel-concrete-steel sandwich composite plates subject to impact and blast load

Advances in Structural Engineering144673-688ASED

Steel-Concrete-Steel sandwich slabs with lightweight core - Static performance

10.1016/j.engstruct.2010.12.019Engineering Structures333981-992ENST

Fatigue performance of lightweight steel-concrete-steel sandwich systems

10.1016/j.jcsr.2009.07.009Journal of Constructional Steel Research662256-27

Effect of preload on the axial capacity of concrete-filled composite columns

10.1016/j.jcsr.2008.03.023Journal of Constructional Steel Research653709-72

Novel deployable structural systems

ICASS '09/IJSSD - Proceedings of Sixth International Conference on Advances in Steel Structures and Progress in Structural Stability and Dynamics91-10