Flexural Behavior Characteristics of Steel Tubes Filled with SFRCCs Incorporating Recycled Materials.

This study deals with the effect of fly ash and recycled sand on the flexural behavior of SFRCCs (steel fiber-reinforced cementitious composites)-filled steel tubes. As a result of the compressive test, the elastic modulus was reduced by the addition of micro steel fiber, and the fly ash and recycled sand replacement decreased the elastic modulus and increased the Poisson's ratio. As a result of the bending and direct tensile tests, strength enhancement by the incorporation of micro steel fibers was observed, and a smooth descending curve was confirmed after initial cracking.

Evaluation of Reducing NO and SO Concentration in Nano SiO-TiO Photocatalytic Concrete Blocks.

The use of titanium dioxide in concrete block pavements is a promising approach to reduce air pollution in the roadside. When TiO is used as an additive of cement concrete or mortar, it is not dispersed uniformly due to agglomeration between particles causing the degradation of photocatalytic reaction. To improve the photocatalytic performance of TiO, the Nano SiO-TiO (NST) has been developed by coating TiO with SiO as a support using the sol-gel method.

Photocatalytic and Pozzolanic Properties of Nano-SiO₂/Al₂O₃-TiO₂ Powder for Functional Mortar.

The present study intended to find a way to use TiO₂, one of the most widely used photocatalysts, as a construction material. To that end, nano-SiO₂/Al₂O₃-TiO₂ powder (NTCP) was synthesized by coating SiO₂ and Al₂O₃ support materials with TiO₂. The NTCP was anatase phase spherical particles, specific surface areas were 319 m²/g and 267 m²/g for the SiO₂-TiO₂ powder and Al₂O₃-TiO₂ powder.

Bonding Behavior of Deformed Steel Rebars in Sustainable Concrete Containing both Fine and Coarse Recycled Aggregates.

In order to assess the bond behavior of deformed steel rebars in recycled-aggregate concrete (RAC) incorporating both fine and coarse recycled aggregate, pull-out tests were carried out in this study on 16-mm diameter deformed steel rebars embedded concentrically in RAC. The concrete was designed using equivalently mixed proportions of both recycled coarse aggregate and recycled fine aggregate. The tests employed five types of recycled aggregate replacement combinations and three types of rebar placement orientation (i.

An experimental study on the hazard assessment and mechanical properties of porous concrete utilizing coal bottom ash coarse aggregate in Korea.

This study evaluates quality properties and toxicity of coal bottom ash coarse aggregate and analyzes mechanical properties of porous concrete depending on mixing rates of coal bottom ash. As a result, soundness and resistance to abrasion of coal bottom ash coarse aggregate were satisfied according to the standard of coarse aggregate for concrete. To satisfy the standard pertaining to chloride content, the coarse aggregates have to be washed more than twice.