Microconcreto leve autoadensável com AE-0500: estudo experimental para aplicações estruturais de alto desempenho

Abstract

Considering the increasing demand for lightweight, high-performance structural solutions, this study aimed to develop and characterize mixtures of Lightweight Self-Compacting Microconcrete (LSCMC) using AE-0500 expanded clay as lightweight aggregate, targeting a maximum density of 2.000 kg/m³ and a minimum compressive strength of 50 MPa. The methodology comprised two experimental stages. In Phase 1, lightweight concrete mixtures with different types and proportions of aggregates (AE-1506, AE-0500, and crushed stone 0) were evaluated, resulting in the selection of AE-0500 as reference aggregate after achieving a compressive strength of 47.69 MPa and a Structural Efficiency Factor (SEF) of 23.91 MPa·dm³/kg. Phase 2 involved adapting the selected mixture to meet self-compacting requirements as established by the Brazilian standard ABNT NBR 15823. Six mixtures were produced, varying aggregate volume and the AE-0500-to-sand ratio. Mixtures F1-5050 and F2-6040 stood out in the fresh state, achieving slump flow values above 760 mm (SF3), T500 times below 2 seconds (VS1), and a Visual Stability Index (VSI0). In the hardened state, mixture F1-5050 reached a compressive strength of 65.99 MPa, SEF of 34.72 MPa·dm³/kg, and an elastic modulus of 36.48 GPa, surpassing Rossignolo’s theoretical prediction (2005) by 5.45%. Results confirm the technical viability of LSCMC as a lightweight, high-strength, and self-compacting solution, and classifying as a high strength lightweight and self-compacting concrete, a HSLWSCC.