Structural Behavior of Recycled Aggregate Concrete Elements

2017 ◽  
pp. 321-393
Author(s):  
Jianzhuang Xiao
Keyword(s):  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Structural Behavior ◽  
Aggregate Concrete ◽  
Concrete Elements

Structural Behavior of Recycled Aggregate Concrete Beam-Column Connection in Presence of Micro Concrete at Joint Region

Structures ◽  
2017 ◽  
Vol 11 ◽  
pp. 243-251 ◽  
Author(s):  
C. Marthong ◽  
A.S. Sangma ◽  
S.A. Choudhury ◽  
R.N. Pyrbot ◽  
S.L. Tron ◽  
...  
Keyword(s):  
Concrete Beam ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Structural Behavior ◽  
Joint Region ◽  
Aggregate Concrete

scholarly journals Eurocode Design of Recycled Aggregate Concrete for Chloride Environments: Stochastic Modeling of Chloride Migration and Reliability-Based Calibration of Cover

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 284
Author(s):  
António Albuquerque ◽  
João Nuno Pacheco ◽  
Jorge de Brito
Keyword(s):  
Stochastic Modeling ◽  
Design Guidelines ◽  
Concrete Cover ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Chloride Ingress ◽  
Aggregate Concrete ◽  
Chloride Migration ◽  
Cover Design ◽  
Concrete Elements

Recycled aggregate concrete is a solution used to minimize the environmental impact of the concrete industry. Notwithstanding research worldwide validating structural applications of recycled aggregate concrete, specific design guidelines are lacking and are needed to address reservations of construction agents. Design guidelines should be based on reliability concepts, including the stochastic modeling of material properties and the calibration of design clauses through reliability methods. This paper concerns the concrete cover design of recycled aggregate concrete elements exposed to chloride ingress. Only coarse recycled aggregates produced from concrete waste are studied. The paper describes the chloride ingress model of fib Bulletin 34, presents experiments on the chloride ion migration of several analogue natural and recycled aggregate concrete mixes, tackles the stochastic modeling of the chloride migration coefficient, and calibrates concrete cover design for recycled aggregate concrete using reliability methods. The concrete cover design followed the deemed-to-satisfy provisions of Eurocode 2 and EN 206. The case studies used in the reliability analyses covered several design situations. A 5 mm increase of concrete cover is recommended as a simple option that ensures that the probability of depassivation due to chloride ingress on recycled aggregate concrete elements is equivalent to that for analogue natural aggregate concrete elements.

scholarly journals Eurocode Shear Design of Coarse Recycled Aggregate Concrete: Reliability Analysis and Partial Factor Calibration

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4081
Author(s):  
João Pacheco ◽  
Jorge de Brito ◽  
Carlos Chastre ◽  
Luís Evangelista
Keyword(s):  
Model Uncertainty ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Shear Reinforcement ◽  
Aggregate Concrete ◽  
Natural Aggregate ◽  
Shear Design ◽  
Partial Factor ◽  
Concrete Elements

This paper contributes to the definition of design clauses for coarse recycled aggregate concrete. One of the main reasons for scepticism towards recycled aggregate concrete is the perceived notion that the heterogeneity of recycled aggregates may increase the uncertainty of the behaviour of concrete. Therefore, the paper uses structural reliability concepts to propose partial factors for recycled aggregate concrete’s design for shear failure. The paper builds upon a previous publication by the authors, in which the model uncertainty of recycled aggregate concrete elements designed for shear, with and without shear reinforcement, was compared with that of natural aggregate concrete elements. In that paper, the statistics of the model uncertainty for recycled aggregate concrete shear design were indeed found to be less favourable than those of natural aggregate concrete. Therefore, a partial factor for recycled aggregate concrete design is needed to ensure safety. This paper presents partial factors calibrated with explicit reliability analyses for different cases of design concerning beams (in the case of shear design of elements with shear reinforcement) and slabs (for the design of elements without shear reinforcement). For full incorporation of coarse recycled concrete aggregates and the design of elements without shear reinforcement, the calibrated partial factor reduces the design value of shear resistance by 10% (design with EN1992) or 15% (design with prEN1992) in comparison to natural aggregate concrete’s design. For the shear design of elements with shear reinforcement, the partial factor decreases resistance by 5% but a sensitivity analysis showed that the reduction might be, under pessimistic expectations, of up to 20%.

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