Structural behavior of reinforced concrete one-way slabs cast with self-compacting concrete containing recycled concrete as coarse aggregate

Abstract EN

This work deals with the effect of using Recycled Concrete Aggregate (RCA) as a partial replacement of coarse aggregate in Self-Compacting Concrete (SCC), on the structural behavior (flexure and shear) of reinforced concrete one-way slTo the authors' knowledge, this study is one of limited studies concerning the behavior of recycled aggregate concrete one-way slsubjected to line loading with significant replacement of conventional aggregates by recycled concrete aggregate (up to 75 %).

Three replacement ratios were considered 25 %, 50 % and, 75 %.

The mixes (with natural stone coarse aggregate, NCA) have an averaged compressive strength of (Fcu = 42 MPa) at the age of 28 days with a tolerance of (± 1.

5 MPa).

While, the mixes (with RCA) have an averaged compressive strength of (38.

5, 36.

5 and 34 MPa) for the three replacement ratios respectively, at the age of 28 days with a tolerance of (± 2 MPa).

All the slwere cast with length of (1600 mm), width of (600 mm), while the thickness was variable.

For this purpose, sixteen reinforced concrete one-way slwere cast and divided into five groups (G1 to G5).

Different parameters that affect the behavior of one-way slwere studied and include type of failure, replacement ratios of NCA by RCA, amount of main reinforcement, thickness and locations of line loadings along the span.

Hardened concrete specimens results show that the compressive strength Fcu, tensile strength Ft, modulus of rupture Fr and modulus of elasticity E were decreased as the RCA replacement increased.

The experimental results of slshow that the ultimate capacity of sldecreased as the RCA replacement increased, the deflection and strain increase as the RCA replacement increases and the crack width increases as the RCA replacement increases.

From the results of ultimate capacity, cracking load and moment, deflections, crack width and pattern and concrete surface strains, it can be concluded that the recycled concrete aggregate can be used as a partial replacement of natural coarse aggregate to produce self-compacting concrete mixes.

Also, the behavior of one way slcast with SCC containing RCA is acceptable.