Investigation of the Variability of the Concrete Elastic Modulus Using Non-Destructive Testing

• Grant number: 25/21894-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2025
• End date: September 30, 2026
• Field of knowledge: Engineering - Civil Engineering - Structural Engineering
• Principal Investigator: Claudius de Sousa Barbosa
• Grantee: Pedro Nishimura Carvalho
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The design of reinforced or prestressed concrete structures must comply with the guidelines of NBR 6118 (2023). Among the mechanical properties of concrete, two are particularly relevant due to their direct influence on structural design: compressive strength and elastic modulus. Similar to other international technical standards, the Brazilian code allows, in the absence of experimental data, the estimation of the elastic modulus based on the characteristic compressive strength, incorporating a correction factor related to the type of coarse aggregate used in the mix, which may lead to differences of up to 50%. However, construction methodology, quality control procedures, and the structural performance of the project can result in significant variations from the expected values. The aim of this research is to characterize the elastic modulus of concrete as delivered on-site, using distinct experimental techniques such as standardized tests on cylindrical and cubic specimens, ultrasonic pulse velocity, and acoustic resonance, in order to determine the dynamic elastic modulus in accordance with NBR 8522-2 (2021). Following a predominantly experimental methodology, concrete cores will be extracted from two different construction sites-one a multi-story residential building and the other an infrastructure project-with distinct characteristic compressive strengths. Laboratory tests will be carried out to determine both the compressive strength and the elastic modulus of the concrete, using static testing complemented by non-destructive methods (NDT). Statistical analyses of the results will provide a critical assessment of the formulation presented in NBR 6118 (2023), as well as correlations with the outcomes of the non-destructive testing procedures (AU)