Effect of concrete wet packing density on the uni‐axial strength of manufactured sand CFST columns

Abstract

River sand (RS) has been the most popular fine aggregate in concrete production. Recently, because of the continuing decline in supply of RS, alternative source of fine aggregates is needed. Manufactured sand (MS), which is produced by mechanical crushing of virgin rock or construction waste, is becoming more popular for replacing RS. Concrete containing MS has higher compressive strength but is more brittle. To promote the application of MS in concrete, concrete‐filled‐steel‐tube (CFST) column is advocated to restore the ductility by composite action. It is believed that the improved strength and ductility of CFST column containing MS is due to the enhanced wet packing density (WPD) of concrete, which has been researched to affect significantly the mechanical performance of concrete. Nonetheless, there was very limited research carried out on the effect of WPD on the behavior of confined concrete and CFST column. Ergo, 15 CFST column specimens with MS replacing RS partially or totally were prepared and tested under uni‐axial compression. It is evident that CFST specimens with concrete containing blended fine aggregates showed different axial load‐strain behavior to those with RS concrete (especially the maximum strength and postelastic slope). More importantly, the normalized strength (maximum strength to squash load) of CFST specimens can be correlated positively to the WPD. This article thus provides a new insight into the interdependence between the uni‐axial strength of CFST columns and the WPD of the in‐filled concrete.

Effect of Municipal Solid Waste Slag on the Durability of Cementitious Composites in Terms of Resistance to Freeze–Thaw Cycling

“…The greatest decrease in strength was noted for mortars made with the higher-grade cement CEM 52.5. This showed that as the compressive strength increased, the cement matrix became more brittle, resulting in a decrease in flexural strength [ 36 , 37 ]. In addition, the introduced slag, due to its porous structure, weakened the contact zone between the aggregate and the cement binder, resulting in a decrease in mechanical performance.…”

Impact of crumb rubber particle size on the mechanical and microstructure properties of rubberized concrete

“…However, when the fineness modulus is larger, an overall increasing trend is observed. Rubber particles distribute homogenously in the cementitious system and filling the voids between aggregates, resulting in larger apparent density and higher strength 65‐68 …”

“…Rubber particles distribute homogenously in the cementitious system and filling the voids between aggregates, resulting in larger apparent density and higher strength. [65][66][67][68]…”

Synthesis of PVA Nanofibers to Enhance the Mechanical and Thermal Properties of PMMA Matrix for Denture Base Applications

“…The DSC exam is a technique used to measure the temperature and heat flow associated with phase transition temperatures of materials. (27,28) The DSC test of prepared samples was conducted in order to understanding the thermal behavior of the samples. Figure 7 shown the DSC curves of pure PMMA and PMMA enhanced with (0,02) PVA nanofibers and the results of Tg and T decomposition were listed in table 2.…”