Finite element model-based code calibration for design of steel fibre reinforced recycled aggregate concrete beams

Abstract

As the construction industry is rapidly growing, the importance given to sustainable construction techniques has increased, to protect the environment and the limited reserves of natural resources. In order to reduce the negative environmental impact of the construction industry and to meet the increasing global demand for raw materials, the significance of recycling and reusing construction waste has increased over the years. Considering the wide applications of concrete and the large consumption of coarse aggregates used in concrete on a global scale, using Recycled Aggregate (RA) in concrete is an environment-friendly and sustainable construction alternative. However, Recycled Aggregate Concrete (RAC) does not exhibit adequate structural performance due to its inferior material properties compared to those of Natural Aggregate Concrete (NAC). At present, RAC is restricted to limited structural use and is extensively used only in pavements and as shotcrete in tunnels. Some previous studies have shown that RAC with adequate structural performance can be produced using various techniques. In this study, the particular technique of adding another material, Steel Fibre (SF), is investigated. SF improves the mechanical performance of RAC and makes it suitable for structural applications, especially under flexural load. This research aims to replace NAC with RAC that incorporates SF. The use of the new material, Steel Fibre Reinforced Recycled Aggregate Concrete (SFRRAC), in fabricating structural members subjected to flexure is proposed to gain advantages in terms of environmental effects, production costs and structural properties. Structural members fabricated using a new material such as SFRRAC should be designed according to proper design models and guidelines. The current design guidelines are limited to NAC and cannot be directly applied to SFRRAC due to the xxi change in the material properties. This research proposes a design model for SFRRAC beam cross-sections under flexure, developed using a reliability based framework consisting of the following four parts: (i) a new theoretical model development for predicting the moment-capacities of SFRRAC beam cross-sections; (ii) experimental investigation of SFRRAC specimens at material-level and member level; (iii) numerical investigation on SFRRAC beams using Finite Element Analysis (FEA); and (iv) capacity factor calibration for a SFRRAC flexural capacity prediction model using the theoretical predictions and the adaptively combined database of experimental and FEA results.

Date of Award	2019
Original language	English