Plastic Rotation Capacity of Lightweight Aggregate Concrete Beams considering Unit Weight of Concrete

2021 ◽  
Vol 33 (1) ◽  
pp. 31-37
Author(s):  
Keun-Hyeok Yang ◽  
Ju-Hyun Mun ◽  
Chae-Rim Im
Keyword(s):  
Concrete Beams ◽  
Lightweight Aggregate ◽  
Unit Weight ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Plastic Rotation ◽  
Rotation Capacity ◽  
Plastic Rotation Capacity

scholarly journals Neutral Axis Depth versus Ductility and Plastic Rotation Capacity on Bending in Lightweight-Aggregate Concrete Beams

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3479 ◽  
Author(s):  
Luís Bernardo ◽  
Miguel Nepomuceno ◽  
Hugo Pinto
Keyword(s):  
Concrete Beams ◽  
Lightweight Aggregate ◽  
Neutral Axis ◽  
Experimental Program ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Plastic Rotation ◽  
Rotation Capacity ◽  
Flexural Ductility ◽  
Plastic Rotation Capacity

This article presents an experimental study on the evolution of the neutral axis depth at failure in the critical section with the flexural ductility and plastic rotation capacity of reinforced concrete (RC) lightweight-aggregate concrete (LWAC) beams. For this, the results of a previous experimental program involving RC LWAC beams tested in flexure until failure are used. The variable studies were the concrete compressive strength (between 22.0 and 60.4 MPa and dry density between 1651 and 1953 kg/m3) and the longitudinal tensile reinforcement ratio (between 0.13% and 2.69%). The flexural ductility and the plastic rotation capacity of the RC LWAC beams are characterized by a ductility index and a plastic trend parameter, respectively. The influence of the variable studies, as well as the relation of the flexural ductility and plastic rotation capacity with the values for the neutral axis depth at failure are analyzed and discussed. Some conclusions are drawn which can be useful for the design of RC LWAC beams for flexure. In particular, it is shown that the practical rule of limiting the neutral axis depth at failure to ensure ductile behavior, as used in normal-weight aggregate concrete beams, is also valid for RC LWAC beams.

scholarly journals Evaluation of Heat Insulation and Surface Resistivity of Mineral Lightweight Aggregate Concrete(MLAC)

2020 ◽  
Vol 10 (21) ◽  
pp. 7871
Author(s):  
Jung-Nan Chang ◽  
Tung-Tsan Chen ◽  
Chang-Chi Hung ◽  
Her-Yung Wang
Keyword(s):  
Heat Insulation ◽  
Lightweight Aggregate ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Unit Weight ◽  
Lightweight Aggregate Concrete ◽  
Control Group ◽  
K Value ◽  
Aggregate Concrete ◽  
Binder Ratio

In this study, the fixed water/binder ratio is 0.40, four mineral admixtures: fly ash (FA), blast furnace slag (BFS), desulphurization slag (DLS), and glass LED powder (GLP), were added to lightweight aggregate concrete (LWAC), replacing 10% or 30% of the cement content, to study their heat insulation efficiency and engineering performance and to compare the economic impact of mineral admixtures on LWAC. In terms of heat insulation, the thermal conductivity (K value) of the controlled sample was 0.484 kcal/(m.h. °C) and the addition of mineral admixtures changed the concrete unit weight and water absorption ratio, thus reducing the K value by 0.41% to 25.71% and improving the heat insulation. As the mineral admixture hydration products and chemical contents differed, the heat insulation of the LWAC varied as well. The study indicated that the heat insulation is the greatest in concrete with the addition of 30% FA, followed by concrete with the addition of 10% GLP. The addition of mineral admixtures is 30%, the resistivity is 72–455% of the control group, and the resistivity of FA and GLP is higher than the control group. The study is indicated that the proper addition of mineral powder material has an apparent effect on increasing heat insulation efficiency.

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