Page 11 - New Trends in Eco efficient and Recycled Concrete

x Contents

10.5 Results and discussion 281
10.5.1 Quality of recycled concrete aggregate 281
10.5.2 Durability 282
10.5.3 LCI modelling approach 283
10.5.4 CO 2 uptake 284
10.6 Conclusions 286
References 287
11 Equivalent functional unit in recycled aggregate concrete 293
Jorge de Brito, Luı ´ s Evangelista and Jose ´ D. Silvestre
11.1 Introduction 293
11.2 Definition of declared unit and functional unit 294
11.2.1 LCA analyses and balanced comparisons 294
11.2.2 Definition of the concepts of declared unit
and functional unit 295
11.2.3 Integration of these concepts in an LCA 296
11.2.4 Ways of defining equivalent functional units 296
11.2.5 Application to concrete 296
11.3 Relative performance of recycled aggregates concrete versus
conventional concrete 297
11.3.1 Recycled aggregates 297
11.3.2 Influence on the properties of fresh concrete 299
11.3.3 Influence on the mechanical properties of concrete 299
11.3.4 Influence on the durability and long-term performance
of concrete 300
11.4 Methodology for the definition of equivalent functional unit
for recycled aggregate concrete 300
11.4.1 Properties to take into account 301
11.4.2 Simplified approach (based on the compressive
strength classes only) 302
11.4.3 Discussion of a multi-criteria approach
(based on structural functionality) 303
11.5 Proposal of an equivalent functional unit for recycled
aggregate concrete 303
11.5.1 Practical rules to compare different properties
of RAC and NAC 303
11.5.2 Limit states 305
11.6 Calculation of the equivalent functional unit 306
11.6.1 K as function of durability 306
11.6.2 K as function of long-term deflection SLS 306
11.6.3 K as a function of bending ULS 308
11.6.4 K as a function of cracking SLS 309
11.6.5 Multi-criteria analysis 309